Parallelograms of speeds on the impeller

When entering the blade and exiting the blade, each particle of liquid acquires, respectively:

1. Circumferential velocities U 1 and U 2 directed tangentially to the input and
output to the circumferences of the impeller.

2. Relative velocities W 1 and W 2 directed tangentially to the surface of the blade profile.

3. Absolute velocities C 1 and C 2 obtained as a result of geometric addition U1,

Since the pump is a mechanism that converts the mechanical energy of the drive into energy (pressure) that imparts the movement of fluid in the inter-blade space of the wheel, its theoretical value (pressure) obtained during pump operation can be determined using Euler’s formula:

C 2 U 2 сos α 2 – C 1 U 1 сos α 1

N t ∞ = __________________________

Due to the fact that a centrifugal pump does not have a guide vane when the liquid enters the blades, in order to avoid large hydraulic losses from liquid impacts on the blades and reduce pressure losses, the liquid inlet to the wheel is made radial (the direction of the absolute speed C 1 is radial). In this case, α 1 = 90, then cos 90 - 0, therefore, the product C 1 U 1 cos α 1 = 0. Thus, the basic equation for the pressure of a centrifugal pump, or the Euler equation, will take the form:

Н t ∞ = C 2 U 2 сos α 2 / g

In a real pump there is a finite number of blades and pressure losses due to turbulence of fluid particles are taken into account by the coefficient φ (phi), and hydraulic resistance is taken into account by the hydraulic efficiency - ηg, then the actual pressure will take the form: Нд = Нt φηг

Taking into account all losses, the efficiency of a centrifugal pump is ηn 0.46-0.80.

Under operating conditions, the pressure of a centrifugal pump is determined by an empirical formula and depends on the speed of the drive motor and the diameter of the impeller:

Nn = k"* n 2 * D 2,

where: k" - experimental dimensionless coefficient

n - impeller rotation speed, rpm.

D - outer diameter of the wheel, m.

The pump flow hp -1 is approximately determined by the diameter n of the discharge pipe:

Qн = k"d 2

where: k" - for pipe diameter up to 100 mm - 13-48, more than 100 mm - 20-25

d – diameter of the discharge pipe in dm.

2. To ensure normal and safe operation of the vessel, as well as to create appropriate conditions for people to stay on it, ship systems are used.
The ship system is understood as a network of pipelines with mechanisms, apparatus and instruments that perform certain functions on the ship. With the help of ship systems, the following is carried out: receiving and removing water ballast, fighting fires, draining ship compartments from water accumulating in them, supplying passengers and crew with drinking and washing water, removing sewage and contaminated water, maintaining the necessary air parameters (conditions) in the premises. Some vessels, such as tankers, icebreakers, refrigerators, etc., are equipped with special systems due to specific operating conditions. Thus, tankers are equipped with systems designed to receive and pump out liquid cargo, heat it to facilitate pumping, wash tanks and clean them from oil residues. The large number of functions performed by ship systems determines the variety of their design forms and the mechanical equipment used. Ship systems include: pipelines, consisting of interconnected individual pipes and fittings (gates, valves, taps), which are used to turn the system and its sections on or off, as well as for various adjustments and switching; mechanisms (pumps, fans, compressors) that impart mechanical energy to the medium flowing through them and ensure the latter moves through pipelines; vessels (tanks, cylinders, etc.) for storing a particular medium; various devices (heaters, coolers, evaporators, etc.) used to change the state of the environment; means of managing the system and monitoring its operation.
Of the listed mechanisms and apparatus, each given ship system may contain only some of them. This depends on the purpose of the system and the nature of the functions it performs.
In addition to general ship systems, the ship has systems that service the ship's power plant. On diesel ships, these systems supply the main and auxiliary engines with fuel, oil, cooling water and compressed air. Ship power plant systems are discussed in a course dedicated to these plants.

3. Modern sea vessels are places of permanent work and residence for crew members and long-term stay for passengers. Therefore, in the residential, service, passenger and public premises of these ships in any areas of navigation, at any time of the year and under any meteorological conditions, a microclimate favorable for people must be maintained, i.e. the totality of the composition and parameters of the air condition, as well as thermal radiation in limited indoor spaces. The microclimate in the ship's premises is ensured using comfortable air conditioning systems and appropriate insulation of the premises, the temperature of the internal surface of which should not differ significantly (by more than 2° C) from the air temperature in these premises.

Marine refrigeration unit.
1 - compressor; 2 - capacitor; 3 - expansion valve; 4 - evaporator; 5 - fan; o - refrigerated chamber; 7 - evaporation plant room.

Comfort air conditioning systems designed for cleaning and heat and humidity treatment of air supplied to premises. At the same time, certain, predetermined conditions must be ensured in the room, i.e. parameters of the composition and state of the air: its purity, a sufficient percentage of oxygen content, temperature, relative humidity and mobility (speed of movement). These given air conditions determine the so-called comfortable conditions for people.

In various areas of navigation of ships in different times year, the outside (atmospheric) air temperature can reach the highest (up to 40-45°C) and lowest (down to -50°C) values. The temperature of the sea water can vary widely: from +35°C to -2°C, and the moisture content in 1 kg of air is from 24-26 to 0.1-0.5 g. In such conditions, the vessel’s navigation is significantly The intensity of solar radiation also changes. If we take into account that ships are large metal structures with a high thermal conductivity coefficient, then it becomes clear how great the influence of external conditions on the formation of the microclimate in ship premises is. In addition, there are quite a lot of internal objects of heat and moisture release on the ship.

All this requires the ship's comfort air conditioning system to be highly flexible (maneuverable) in operation. In warm areas (or in the summer), it should ensure the removal of appropriate heat and moisture from the premises, and in cold areas (or in winter time) - compensate for heat loss and remove excess moisture released mainly by people, as well as some equipment. In the summer season, outside air usually needs to be cooled and dehumidified before being supplied to the premises, and in winter it needs to be heated and humidified (although outside air in winter has a high relative humidity - up to 80-90%, it contains very little large number moisture, no more than 1-3 g per 1 kg of air).

Air heating and humidification carried out, as a rule, with steam or water, and its cooling and drying is done using refrigeration machines. Thus, refrigeration machines are an integral part of shipboard comfort air conditioning installations (in the future, for the sake of brevity, we will omit the word “comfortable”).

In addition, refrigeration machines are used on almost all ships of the sea and river fleet to preserve supplies, as well as on fishing, production and transport refrigerated vessels for processing and storing perishable goods (this function of refrigeration machines is usually called refrigeration). In recent years, refrigeration machines have been used to dehumidify air in the holds of dry cargo ships and tanks of oil tankers. This prevents damage to hygroscopic cargo (flour, grain, cotton, tobacco, etc.), damage to equipment and mechanisms transported on ships and significantly reduces corrosion of internal metal parts ship hulls and equipment. This treatment of air in holds and tanks is usually called technical conditioning.

The first experience of using “machine” cooling on ships dates back to the 70-80s of the last century, when almost simultaneously steam compressor ammonia, carbon dioxide and sulfur dioxide, air and absorption refrigeration machines were created and began to spread. Thus, in 1876, the French engineer-inventor Charles Tellier successfully used “machine” cold for the first time on the Frigorific steamship to transport chilled meat from Buenos Aires to Rouen. In 1877, the steamship Paraguay, equipped with an absorption refrigeration unit, delivered frozen meat from South America to Le Havre, and the meat was frozen on the same ship in special chambers. Following this, successful flights with meat were carried out from Australia to England, in particular on the Strathleven steamship, equipped with an air refrigeration machine. By 1930, the world maritime refrigerated fleet already consisted of 1,100 ships with a total cargo capacity of 1.5 million standard tons.

Fire Pumps

Used as fire safety installations on tankers transporting liquefied natural gas, as well as on tankers converted into storage facilities in oil field areas and production facilities Manufacturer Ellehammer

As a rule, they are used as backup systems that duplicate ring fire extinguishing systems, when 3-4 emergency fire pumps do not allow water pressure to drop in the event of a failure of the main system.

Emergency fire pumps equipped with electric or diesel engines. The range of such pumps is very large: from pumps with a 4-cylinder engine, developing a power of 120 hp, which pumps 70 m3 per hour - to huge units with a 12-cylinder engine, with a capacity of 38 liters, developing a power of 1400 hp, which are capable of pumping more than 2000 m3 per hour at a pressure of 12 bar.

Fire pumps and their kingstons must be located on the ship in heated

rooms below the waterline, pumps must have independent drives and the flow rate of each stationary pump must be at least 80 % total flow divided by the number of pumps in the system, but not less 25 m3/h. Fire system pumps should not be used to drain compartments in which petroleum products or residues of other flammable liquids have been stored.

A stationary fire pump can be used on a ship for other purposes as long as another pump is kept in constant readiness for immediate action to extinguish the fire.
General flow of stationary pumps should be increased if they simultaneously serve other fire extinguishing systems along with the fire system. When determining this flow, it is necessary to take into account the pressure in the systems. If the pressure in the connected systems is higher than in the fire system, the pump flow must be increased due to the increase in flow through the fire nozzles as the pressure increases.
Stationary emergency fire pump is provided with everything necessary for operation (energy sources for its drive, receiving seacocks) in the event of failure of the main pumps and is connected to the ship's system. If necessary, it is provided with a self-priming device.

Emergency pumps located in separate rooms, and diesel-driven emergency pumps are provided with fuel for 18 h work. The supply of the emergency pump must be sufficient to operate two barrels with the largest nozzle diameter adopted for a given vessel, and not less 40% total pump supply, but not less 25 m3/h.

Centrifugal Fire Pump Vacuum System designed for pre-filling the suction line and pump with water when drawing water from an open water source (reservoir). In addition, using a vacuum system, it is possible to create a vacuum (vacuum) in the housing of a centrifugal fire pump to check the tightness of the fire pump.

Currently, two types of vacuum systems are used on domestic fire trucks. The first type of vacuum system is based on gas jet vacuum apparatus(GVA) with a jet type pump, and based on the second type - vane vacuum pump(volumetric type).

Conclusion on the issue: Modern brands of fire trucks use various vacuum systems.

Gas jet vacuum systems

This vacuum system consists of the following main elements: a vacuum valve (gate) installed on the fire pump manifold, a gas-jet vacuum apparatus installed in the exhaust tract of the fire truck engine, in front of the muffler, a GVA control mechanism, the control lever of which is located in the pump compartment, and a pipeline , connecting the gas-jet vacuum apparatus and the vacuum valve (gate). A schematic diagram of the vacuum system is shown in Fig. 1.

Rice. 1 Diagram of the vacuum system of a centrifugal fire pump

1 – body of a gas-jet vacuum apparatus; 2 – damper; 3 – jet pump; 4 – pipeline; 5 – hole to the cavity of the fire pump; 6 – spring; 7 – valve; 8 – eccentric; 9 – eccentric axis; 10 – eccentric handle; 11 – vacuum valve body; 12 – hole; 13 – exhaust pipe, 14 – valve seat.

The housing of the gas-jet vacuum apparatus 1 has a damper 2, which changes the direction of movement of the exhaust gases of the fire truck engine either to the jet pump 3 or into the exhaust pipe 13. The jet pump 3 is connected by a pipeline 4 to the vacuum valve 11. The vacuum valve is installed on the pump and communicates with it through hole 5. Inside the vacuum valve body, springs 6 press two valves 7 against seats 14. When moving handle 10 with axis 9, eccentric 8 presses valves 7 away from seats. The system works as follows.

In the transport position (see Fig. 1 “A”), damper 2 is in a horizontal position. The valves are pressed to the seats by 7 springs 6. The engine exhaust gases pass through housing 1, exhaust pipe 13 and are released into the atmosphere through the muffler.

When drawing water from an open water source (see Fig. 1 “B”), after connecting the suction line to the pump, use the vacuum valve handle to press the bottom valve down. In this case, the pump cavity through the cavity of the vacuum valve and pipeline 4 is connected to the cavity of the jet pump. Damper 2 is moved to a vertical position. The exhaust gases will be directed to the jet pump. A vacuum will be created in the suction cavity of the pump, and the pump will be filled with water under atmospheric pressure.

The vacuum system is turned off after filling the pump with water (see Fig. 1 “B”). By moving the handle, press the upper valve away from the seat. In this case, the lower valve will be pressed against the seat. The suction cavity of the pump is disconnected from the atmosphere. But now pipeline 4 will be connected to the atmosphere through hole 12, and the jet pump will remove water from the vacuum valve and connecting pipelines. This especially needs to be done on winter period to prevent water from freezing in pipelines. Then the handle 10 and the valve 2 are placed in their original position.

Rice. 2 Vacuum valve

(see Fig. 2) is designed to connect the suction cavity of the pump with a gas-jet vacuum apparatus when drawing water from open reservoirs and removing water from pipelines after filling the pump. The valve body 6, cast from cast iron or aluminum alloy, contains two valves 8 and 13. They are pressed by springs 14 to the saddles. When the handle 9 is positioned “away”, the eccentric on the roller 11 pushes the upper valve away from the seat. In this position the pump is disconnected from the jet pump. Moving the handle toward you, we press the bottom valve 13 away from the seat, and the suction cavity of the pump is connected to the jet pump. With the handle in a vertical position, both valves will be pressed against their seats.

In the middle part of the body there is a plate 2 with a hole for connecting the connecting pipeline flange. In the lower part there are two holes, closed with eyes 1 made of organic glass. The body of 4 light bulbs is attached to one of them. The filling of the pump with water is monitored through the peephole.

On modern fire trucks in the vacuum systems of fire pumps, instead of a vacuum valve (gate), ordinary plug water taps are often installed to connect (disconnect) the suction cavity of the fire pump with a jet pump.

Vacuum valve

Gas jet vacuum apparatus designed to create a vacuum in the cavity of the fire pump and suction line when they are pre-filled with water from an open water source. On fire trucks with gasoline engines, single-stage gas-jet vacuum apparatus is installed, the design of one of which is shown in Fig. 3

Housing 5 (distribution chamber) is designed to distribute the exhaust gas flow and is made of gray cast iron. Inside the distribution chamber there are lugs processed for the seats of the rotary valve 14. The housing has flanges for attaching to the engine exhaust tract and for attaching a vacuum jet pump. The valve 14 is made of heat-resistant alloy steel or ductile cast iron and is secured to the axis 12 using a lever 13. The valve axis 12 is assembled with graphite lubricant.

Using the lever 7, the axis 12 rotates, closing either the housing hole 5 or the cavity of the jet pump with a damper 14. The jet vacuum pump consists of a cast iron or steel diffuser 1 and a steel nozzle 3. The jet vacuum pump has a flange for connecting a pipeline 9 that connects the vacuum chamber jet pump with fire pump cavity through a vacuum valve. When the damper 14 is in a vertical position, the exhaust gases pass into the jet pump, as shown by the arrow in Fig. 3.25. Due to the vacuum in vacuum chamber 2, through pipeline 9, air is sucked from the fire pump with the vacuum valve open. Moreover, the greater the speed of passage of exhaust gases through nozzle 3, the greater the vacuum created in vacuum chamber 2, pipeline 9, fire pump and suction line, if it is connected to the pump.

Therefore, in practice, when operating a vacuum jet pump (when drawing water into a fire pump or checking it for leaks), the maximum engine speed of the fire truck is set. If the damper 14 closes the hole in the vacuum jet pump, the exhaust gases pass through the body 5 of the gas jet vacuum apparatus into the muffler and then into the atmosphere.

On fire trucks with a diesel engine, two-stage gas-jet vacuum devices are installed in vacuum systems, which resemble single-stage ones in design and operating principle. The design of these devices is capable of ensuring short-term operation of a diesel engine when back pressure occurs in its exhaust tract. A two-stage gas-jet vacuum apparatus is shown in Fig. 4. The vacuum jet pump of the device is flanged to the housing 1 of the distribution chamber and consists of a nozzle 8, an intermediate nozzle 3, a receiving nozzle 4, a diffuser 2, an intermediate chamber 5, a vacuum chamber 7, connected to the atmosphere, through a nozzle 8, and through an intermediate nozzle - with receiving nozzle and diffuser. In the vacuum chamber 7 there is a hole 9 for connecting it with the cavity of the centrifugal fire pump.

Scheme of operation of the electric pneumatic drive for switching on the GVA

1 – gas-jet vacuum apparatus; 2 – pneumatic cylinder of the GVA drive; 3 – drive lever; 4 – EPC inclusion of GVA; 5 – EPC for turning off GVA; 6 – receiver; 7 – pressure limitation valve; 8 – toggle switch; 9 – atmospheric outlet.

To turn on the vacuum jet pump, it is necessary to turn the valve in the distribution chamber 1 by 90 0. In this case, the damper will block the exit of diesel exhaust gases through the muffler into the atmosphere. Exhaust gases enter the intermediate chamber 5 and, passing through the receiving nozzle 4, create a vacuum in the intermediate nozzle 3. Under the influence of vacuum in the intermediate nozzle 3, atmospheric air passes through the nozzle 8 and increases the vacuum in the vacuum chamber 7. This design of the gas-jet vacuum apparatus allows for efficient the jet pump can operate even at low pressure (velocity) of the exhaust gas flow.

Many modern fire trucks use an electro-pneumatic GVA drive system, the composition, design, principle of operation and operating features of which are outlined in the chapter.

Rice. 4 Two-stage gas jet vacuum apparatus

The procedure for working with a vacuum system based on GVA is given using the example of tank trucks model 63B (137A). To fill a fire pump with water from an open water source or check the fire pump for leaks, you must:

make sure that the fire pump is tight (check that all taps, valves and valves of the fire pump are closed tightly);
open the lower valve of the vacuum seal (turn the handle of the vacuum valve towards you);
turn on the gas-jet vacuum apparatus (use the appropriate control lever to use the damper in the distribution chamber to block the release of exhaust gases through the muffler into the atmosphere);
increase speed idle speed engine to maximum;
observe the appearance of water in the sight glass of the vacuum valve or the reading of the pressure and vacuum gauge on the fire pump;
when water appears in the inspection eye of the vacuum valve or when the vacuum gauge readings indicate a vacuum in the pump of at least 73 kPa (0.73 kgf/cm2), close the lower valve of the vacuum seal (set the vacuum valve handle to a vertical position or turn it away from you), reduce engine speed to minimum idle speed and turn off the gas-jet vacuum apparatus (use the appropriate control lever to shut off the flow of exhaust gases to the jet pump using the damper in the distribution chamber).

The time for filling a fire pump with water at a geometric suction height of 7 m should be no more than 35 s. A vacuum (when checking a fire pump for leaks) within 73...76 kPa should be achieved in no more than 20 s.

The control system for a gas-jet vacuum apparatus can also have a manual or electro-pneumatic drive.

The manual drive for switching on (rotating the damper) is carried out by lever 8 (see Fig. 5) from the pump compartment, connected through a system of rods 10 and 12 to the lever of the damper axis of the gas-jet vacuum apparatus. To ensure a tight fit of the damper to the seats of the distribution chamber of the gas-jet vacuum apparatus during operation of the fire truck, periodic adjustment of the length of the rods is required using the appropriate adjustment units. The tightness of the damper in its vertical position (when the gas-jet vacuum apparatus is turned on) is assessed by the absence of exhaust gases passing through the muffler into the atmosphere (if the damper itself is intact and its drive is in good working order).

Conclusion on the issue:

Electric Vane Vacuum Pump

Currently, in the vacuum systems of centrifugal fire pumps, in order to improve technical and operational characteristics, vane vacuum pumps are installed, incl. ABC-01E and ABC-02E.

In terms of its composition and functional characteristics, the ABC-01E vacuum pump is an autonomous vacuum water filling system for a centrifugal fire pump. ABC-01E includes the following elements: vacuum unit 9, control unit 1 with electrical cables, vacuum valve 4, vacuum valve control cable 2, filling sensor 6, two flexible air lines 3 and 10.

Rice. 4 Vacuum system kit АВС-01Э

The vacuum unit (see Fig. 4) is designed to create the vacuum necessary for filling water in the fire pump cavity and suction hoses. It is a vacuum pump 3 of a vane type with an electric drive 10. The vacuum pump itself consists of a housing part formed by a housing 16 with a sleeve 24 and covers 1 and 15, a rotor 23 with four blades 22 mounted on two ball bearings 18, a lubrication system (including an oil tank 26, tube 25 and nozzle 2) and two pipes 20 and 21 for connecting air ducts.

Working principle of a vacuum pump

The vacuum pump works as follows. When the rotor 23 rotates, the blades 22 are pressed against the sleeve 24 under the action of centrifugal forces and thus form closed working cavities. The working cavities, due to the rotation of the rotor occurring counterclockwise, move from the suction window communicating with the inlet pipe 20 to the outlet window communicating with the outlet pipe 21. When passing through the area of the suction window, each working cavity captures a portion of air and moves it to the exhaust a window through which air is discharged into the atmosphere through an air duct. The movement of air from the suction window into the working cavities and from the working cavities into the exhaust window occurs due to pressure differences that are formed due to the presence of eccentricity between the rotor and the sleeve, leading to compression (expansion) of the volume of the working cavities.

The rubbing surfaces of the vacuum pump are lubricated by engine oil, which is supplied to its suction cavity from the oil tank 26 due to the vacuum created by the vacuum pump itself in the inlet pipe 20. The specified oil flow rate is ensured by a calibrated hole in the nozzle 2. The electric drive of the vacuum pump consists of an electric motor 10 and traction relay 7. Electric motor 10, designed for a voltage of 12 V DC. The rotor 11 of the electric motor at one end rests on the bushing 9, and the other end, through the centering bushing 12, rests on the protruding shaft of the vacuum pump rotor. Therefore, turning on the electric motor after disconnecting it from the vacuum pump is not allowed.

Torque from the engine to the rotor of the vacuum pump is transmitted through pin 13 and a groove at the end of the rotor. Traction relay 7 ensures switching of the contacts of the “+12 V” power circuit when the electric motor is turned on, and also moves the cable strand 2, leading to the opening of the vacuum valve 4, in systems where it is provided. The casing 5 protects the open contacts of the electric motor from accidental short circuit and from water getting on them during operation.

The vacuum valve is designed to automatically shut off the cavity of the fire pump from vacuum unit at the end of the water filling process and installed in addition to the vacuum seal 5. 2, fixed to the rod 7, is connected to the cable core from the traction relay of the vacuum unit. In this case, the cable braid is fixed with a sleeve 4, which has a longitudinal groove for installing the cable. When the traction relay is turned on, the cable core pulls the rod 6 by the earring 2, and the flow cavity of the vacuum valve opens. When the traction relay is turned off (i.e. when the vacuum unit is turned off), rod 6, under the action of spring 9, returns to its original (closed) position. With this position of the rod, the flow cavity of the vacuum valve remains blocked, and the cavities of the centrifugal fire pump and vane pump remain separated. To lubricate the rubbing surfaces of the valve, a lubricating ring 8 is provided, into which oil must be added through hole “A” when operating the vacuum system.

The filling sensor is designed to send signals to the control unit about the completion of the water filling process. The sensor is an electrode installed in an insulator at the top point of the internal cavity of a centrifugal fire pump. When the sensor is filled with water, the electrical resistance between the electrode and the body (“ground”) changes. The change in sensor resistance is recorded by the control unit, which generates a signal to turn off the electric motor of the vacuum unit. At the same time, the “Pump full” indicator on the control panel (unit) turns on.

The control unit (remote control) is designed to ensure operation of the vacuum system in manual and automatic modes.

Toggle switch 1 “Power” serves to supply power to the control circuits of the vacuum unit and to activate light indicators about the state of the vacuum system. Toggle switch 2 “Mode” is designed to change the operating mode of the system – automatic (“Auto”) or manual (“Manual”). Button 8 “Start” is used to turn on the motor of the vacuum unit. Button 6 “Stop” is used to turn off the engine of the vacuum unit and to remove the lock after the “Not normal” indicator lights up. Cables 4 and 5 are designed to connect the control unit, respectively, to the vacuum unit motor and the filling sensor. The remote control has the following light indicators 7, which serve for visual monitoring of the state of the vacuum system:

1. The “Power” indicator lights up when toggle switch 1 “Power” is turned on;

2. Vacuuming – signals that the vacuum pump is turned on when button 8 “Start” is pressed;

Pump full – lights up when the fill sensor is triggered when the fire pump is completely filled with water;
Not normal – records the following malfunctions of the vacuum system:
- the maximum time of continuous operation of the vacuum pump (45...55 seconds) has been exceeded due to insufficient tightness of the suction line or fire pump;
- poor or missing contact in the vacuum unit traction relay circuit due to burnt relay contacts or broken wires;
- The vacuum pump motor is overloaded due to clogging of the vane vacuum pump or other reasons.

On the ABC-02E model and the latest ABC-01E models, the vacuum valve (item 4 in Fig. 3.28) is not installed.

The ABC-02E vacuum pump ensures that the vacuum system operates only in manual mode.

Depending on the combination of the position of the “Power” and “Mode” toggle switches, the vacuum system can be in four possible states:

Inoperative The “Power” toggle switch should be in the “Off” position, and the “Mode” toggle switch should be in the “Auto” position. This position of the toggle switches is the only one in which pressing the “Start” button does not turn on the electric motor of the vacuum unit. Indication is disabled.
In automatic mode(main mode) the “Power” toggle switch should be in the “On” position, and the “Mode” toggle switch should be in the “Auto” position. In this case, the electric motor is turned on by briefly pressing the “Start” button. The shutdown is performed either automatically (when the filling sensor or one of the types of electric drive protection is triggered), or forcedly by pressing the “Stop” button. The indicator is on and reflects the state of the vacuum system.
In manual mode The “Power” toggle switch should be in the “On” position, and the “Mode” toggle switch should be in the “Manual” position. The engine is turned on by pressing the “Start” button and runs as long as the “Start” button is held down. In this mode, the electronic protection of the drive is disabled, and the readings of the light indicators only visually reflect the water filling process. The manual mode is designed to allow operation in the event of failures in the automation system or false alarms. Control of the moment of completion of the water filling process and shutdown of the vacuum pump motor in manual mode is carried out visually using the “Pump full” indicator.
To ensure the completion of a combat mission during a fire in the event of an electronic unit failure, when the system does not work in automatic mode, and in manual mode the light indicators do not reflect the actual processes taking place, there is emergency mode, in which the “Power” toggle switch must be turned off, and the “Mode” toggle switch must be moved to the “Manual” position. In this mode, the electric motor is controlled in the same way as in manual mode, but the indication is turned off, and the moment of completion of the water filling process and shutdown of the vacuum pump motor is monitored based on the appearance of water from the exhaust pipe. Systematic operation in this mode is unacceptable, because can lead to serious damage to vacuum system components. Therefore, immediately upon returning to the fire station, the cause of the control unit malfunction should be identified and eliminated.

Air ducts 3 and 10 (see Fig. 3.28) are designed, respectively, to connect the cavity of the centrifugal fire pump with the vacuum unit and to direct the exhaust from the vacuum unit.

Operating a Vacuum System with a Vane Pump

Operating order of the vacuum system:

Checking the fire pump for leaks (“dry vacuum”):

a) prepare the fire pump for testing: install a plug on the suction pipe, close all taps and valves;

b) open the vacuum seal;

c) turn on the “Power” toggle switch on the control unit (remote panel);

d) start the vacuum pump: in automatic mode, the start is made by briefly pressing the “Start” button; in manual mode, the “Start” button must be pressed and held down;

e) evacuate the fire pump to a vacuum level of 0.8 kgf/cm 2 (in the normal state of the vacuum pump, fire pump and its communications, this operation takes no more than 10 seconds);

f) stop the vacuum pump: in automatic mode, the stop is forced by pressing the “Stop” button; in manual mode, you need to release the “Start” button;

g) close the vacuum valve and use a stopwatch to check the rate of decrease in vacuum in the cavity of the fire pump;

h) turn off the “Power” toggle switch on the control unit (remote panel), and set the “Mode” toggle switch to the “Auto” position.

Automatic water intake:

b) open the vacuum seal;

c) set the “Mode” toggle switch to the “Auto” position and turn on the “Power” toggle switch;

d) start the vacuum pump - press and release the “Start” button: in this case, simultaneously with the vacuum unit drive turning on, the “Vacuuming” indicator lights up;

e) after the completion of water filling, the drive of the vacuum unit is switched off automatically: in this case, the “Pump is full” indicator lights up and the “Vacuuming” indicator goes out. In the event of a leak in the fire pump, after 45...55 seconds the vacuum pump drive should automatically turn off and the “Not normal” indicator should light up, after which the “Stop” button must be pressed;

g) turn off the “Power” toggle switch on the control unit (remote panel).

As a result of a failure of the filling sensor (this can happen, for example, if a wire is broken), the automatic shutdown of the vacuum pump does not work and the “Pump full” indicator does not light up. This situation is critical, because after the fire pump is filled, the vacuum pump does not turn off and begins to “choke” with water. This mode is immediately detected by the characteristic sound caused by the release of water from the exhaust pipe. In this case, it is recommended, without waiting for the protection to operate, to close the vacuum shutter and forcefully turn off the vacuum pump (using the “Stop” button), and upon completion of work, detect and eliminate the malfunction.

Manual water intake:

a) prepare the fire pump for water intake: close all valves and taps of the fire pump and its communications, connect the suction hoses with a mesh and immerse the end of the suction line into the reservoir;

b) open the vacuum seal;

c) set the “Mode” toggle switch to the “Manual” position and turn on the “Power” toggle switch;

d) start the vacuum pump - press the “Start” button and hold it pressed until the “Pump full” indicator lights up;

e) after filling the water (as soon as the “Pump is full” indicator lights up), stop the vacuum pump - release the “Start” button;

f) close the vacuum valve and start working with the fire pump in accordance with its operating instructions;

g) turn off the “Power” toggle switch on the control unit (remote panel), and set the “Mode” toggle switch to the “Auto” position.

In the event of a pressure failure, it is necessary to stop the fire pump and repeat operations “c” – “e”.

Features of work in winter:

a) After each use of the pumping unit, it is necessary to purge the air lines of the vacuum pump, even in cases where the fire pump supplied water from a tank or hydrant (water can enter the vacuum pump, for example, through a loose or faulty vacuum seal). Purge should be done by briefly (3÷5 seconds) turning on the vacuum pump. In this case, it is necessary to remove the plug from the suction pipe of the fire pump and open the vacuum seal.

b) Before starting work, check the vacuum valve for freezing of its moving part. To check, you need to make sure that its rod is mobile by pulling the earring 2 (see Fig. 3.30), to which the cable core is connected. In the absence of freezing, the earring together with the vacuum valve rod and the core cable should move with a force of approximately 3–5 kgf.

c) To fill the oil tank of the vacuum pump, use winter grades of motor oils (with reduced viscosity).

Conclusion on the issue: In vacuum systems of centrifugal fire pumps, vane vacuum pumps are installed in order to improve technical and operational characteristics.

Maintenance

At simultaneously with checking the fire pump for leaks, check the performance of the gas-jet vacuum apparatus, the vacuum valve and carry out (if necessary) adjustment of the drive rods of the gas-jet vacuum apparatus.

TO-1 includes daily maintenance operations. In addition, if necessary, dismantling, complete disassembly, lubrication, replacement of worn parts and installation of a gas-jet vacuum apparatus and vacuum valve are carried out. To lubricate the damper axis in the distribution chamber of a gas-jet vacuum apparatus, graphite lubricant is used.

At TO-2, in addition to TO-1 operations, the performance of the vacuum system is checked on special stands at the technical diagnostic station (post).

To ensure constant technical readiness of the vacuum system, the following types are provided: maintenance: daily maintenance (ETO) and first maintenance (TO-1). List of works and technical requirements for carrying out these types of maintenance are given in table.

List of works during maintenance vacuum system ABC-01E.

View maintenance	Contents of work	Technical requirements (methodology)
Daily Maintenance (DTO)	1. Check for the presence of oil in the oil tank.	1. Maintain the oil level in the tank at least 1/3 of its volume.
Daily Maintenance (DTO)	2. Checking the functionality of the vacuum pump and the functioning of the lubrication system of the vane pump.	2. Carry out the test in the fire pump leak test mode (“dry vacuum”). When the vacuum pump is turned on, the oil supply tube must be completely filled with oil up to the nozzle.
First maintenance	1. Check the tightness of fasteners.	1. Check the tightness of the fasteners components vacuum system.
	2. Lubricate the vacuum valve rod and control cable.	2. Place a few drops of engine oil into hole A of the vacuum valve body. Disconnect the cable from the vacuum valve and place a few drops of engine oil into the cable.
	3. Checking the axial play of the vacuum valve control cable braid at the point of its connection with the traction relay of the vacuum pump electric drive.	3. Axial play is allowed no more than 0.5 mm. Determine the play by moving the cable braid back and forth. If there is a discrepancy, eliminate the play.
	4. Checking the correct position of the vacuum valve earring 2.	4. Check the gap sizes: — Gap “B” — when the electric drive is not working; — Gap “B” — with the electric drive running. The gap sizes “B” and “C” must be at least 1 mm. If necessary, the gaps should be adjusted. To adjust, disconnect the cable from the vacuum valve, loosen the lock nut and set the earring to the required position; tighten the locknut.
	5. Checking oil consumption.	5. Average oil consumption per operating cycle of 30 seconds. must be at least 2 ml.
	6. Cleaning the working surfaces of the fill sensor.	6. Unscrew the sensor from the housing, Clean the electrode and the visible part of the housing surface down to the base metal.

Conclusion on the issue: Maintenance is necessary to maintain vacuum systems in working condition.

Malfunctions of vacuum systems

When operating a vacuum system as part of a pumping unit, the most typical malfunction of the vacuum system is: the pump does not fill with water (or the required vacuum is not created) when the vacuum system is turned on. This malfunction, if the engine of the fire truck is working properly, can be caused by the following reasons:

The damper does not completely block the exit of exhaust gases through the muffler into the atmosphere. The reasons may be the presence of carbon deposits on the damper and in the GVA housing, violation of the adjustment of the control rod drive, wear of the damper axis.
The diffuser or nozzle of the vacuum jet pump is clogged.
There are leaks in the connections of the vacuum valve and fire pump, the vacuum system pipeline or cracks in it.
There are deformations or cracks in the GVA housing.
There are leaks in the exhaust tract of a fire truck engine (as a rule, they occur due to burnout of the exhaust pipes).
The vacuum system pipeline is clogged or water freezes in it.

Possible malfunctions of the ABC-01E vacuum systemand methods for eliminating them

Name of failure, its external signs	Probable Cause	Elimination method
When the “Power” toggle switch is turned on, the “Power” indicator does not light up.	The control unit fuse has blown.	Replace the fuse.
	Open circuit in the power supply circuit of the control unit.	Eliminate the break.
When operating in automatic mode after drawing water automatic shutdown the vacuum pump does not occur.	Open circuit from the electrode or from the fill sensor housing.	Repair open circuit.
	Reduced electrical conductivity of the housing surface and the fill sensor electrode	Remove the fill sensor and clean the electrode and the surface of its housing from dirt.
	Insufficient supply voltage at the control unit.	Check the reliability of contacts in electrical connections; provide a supply voltage to the control unit of at least 10 V.
In automatic mode, the vacuum pump starts, but after 1-2 seconds. stops; The “Vacuum” indicator goes out and the “Not normal” indicator lights up. In manual mode the pump operates normally.	Unreliable contact in the connecting cables between the control unit and the electric drive of the vacuum pump.	Check the reliability of contacts in electrical connections.
	The wire tips on the contact bolts of the traction relay are oxidized or the nuts securing them are loose.	Clean the ends and tighten the nuts.
	Large (more than 0.5 V) voltage drop between the contact bolts of the traction relay during operation of the electric motor.	Remove the traction relay and check the ease of movement of the armature. If the armature moves freely, then clean the relay contacts or replace it.
The vacuum pump does not start either automatically or manually. After 1-2 seconds. after pressing the “Start” button, the “Vacuum” indicator goes out and the “Not normal” indicator lights up	It is difficult to move the strand of the vacuum valve control cable.	Check the ease of movement of the cable core, if necessary, eliminate a strong bend in the cable or lubricate its core with engine oil.
	It is difficult to move the vacuum valve stem.	Lubricate the valve through hole A. In winter, take measures to prevent freezing of the vacuum valve parts.
	Open power supply circuit	Repair open circuit.
	The position of the vacuum valve earring is broken.	Adjust the position of the earring.
	Electrical break circuits in the cable connecting the control unit to the electric drive of the vacuum unit.	Repair open circuit.
	The contacts of the traction relay are burnt.	Clean the contacts or replace the traction relay.
	The electric motor is overloaded (the vane pump is blocked by frozen water or foreign objects).	Check the condition of the vane pump. In winter, take measures to prevent mutual freezing of vane pump parts.
When operating the vacuum pump, it is noted that the oil consumption is too low (on average less than 1 ml per operating cycle)	The lubricating oil is of the wrong grade or is too viscous.	Replace with all-season motor oil according to GOST 10541.
	The dosing hole of jet 2 in the oil line is clogged.	Clean the dosing hole in the oil line.
	There is air leakage through the joints of the oil pipeline.	Tighten the oil pipe fastening clamps.
When the vacuum pump is running, the required vacuum is not provided	Air leakage in suction hoses, through open valves, drain taps, through damaged air ducts.	Ensure the vacuum volume is sealed.
	Air leakage through the oil tank (with complete absence oils).	Fill the oil tank.
	Insufficient supply voltage to the electric drive of the vacuum unit.	Clear contacts power cables, battery terminals; Lubricate them with petroleum jelly and tighten securely. Charge the battery
	Insufficient lubrication of the vane pump.	Check oil consumption.

Conclusion on the issue: Knowing the structure and possible malfunctions of vacuum systems, the driver can quickly find and eliminate the malfunction.

Lesson conclusion: The vacuum system of a centrifugal fire pump is designed to pre-fill the suction line and pump with water when drawing water from an open water source (reservoir), in addition, using the vacuum system, you can create a vacuum (vacuum) in the body of the centrifugal fire pump to check the tightness of the fire pump.

24 "Bulkhead deck" is the uppermost deck, to which transverse watertight bulkheads are extended.

25 "Deadweight" is the difference (in tons) between the displacement of the ship in water of density 1.025 at the load line corresponding to the assigned summer freeboard, and the displacement of the ship when light.

26 “Lightweight displacement” is the vessel’s displacement (in tons) without cargo, fuel, lubricating oil, ballast, fresh and boiler water in tanks, ship stores, as well as without passengers, crew and their property.

27 "Combination vessel" is a tanker designed to transport oil in bulk or dry cargo in bulk.

28 "Crude oil" is any oil found in natural form in the depths of the earth, petroleum, whether or not processed to facilitate its transportation, including:

1 crude oil from which some distillation fractions may have been removed; And

2 crude oil to which some distillation fractions may have been added.

29 "Dangerous goods" are those goods referred to in regulation VII/2.

30 "Chemical tanker" is a tanker constructed or adapted and used for the carriage in bulk of any liquid flammable product specified:

1 in Chapter 17 of the International Code for the Construction and Equipment of Ships Carrying Dangerous Chemicals in Bulk, hereinafter referred to as the International Bulk Chemical Code, adopted by resolution MSC.4(48) of the Maritime Safety Committee, as may be amended by the Organization; or

2 in Chapter VI of the Code for the Construction and Equipment of Ships Carrying Dangerous Chemicals in Bulk, hereinafter referred to as the "Chemical Bulk Code", adopted by resolution A.212(VII) of the Assembly of the Organization, as amended as have been or may be adopted by the Organization

depending on what is applicable.

31 "Gas carrier" is a tanker built or adapted and used for the carriage in bulk of any liquefied gas or other flammable products specified:

1 in chapter 19 of the International Code for the Construction and Equipment of Ships Carrying Liquefied Gases in Bulk, hereinafter referred to as the International Gas Carrier Code, adopted by resolution MSC.5(48) of the Maritime Safety Committee, as may be amended by the Organization; or

2 in Chapter XIX of the Code for the Construction and Equipment of Ships Carrying Liquefied Gases in Bulk, hereinafter referred to as the LNG Carrier Code, adopted by resolution A.328DH) of the Assembly of the Organization, as amended as have been or may be adopted by the Organization, as applicable.

32 "Cargo area" is the part of the ship containing cargo tanks, slop tanks and cargo pump rooms, including pump rooms, cofferdams, ballast spaces and void spaces adjacent to cargo tanks, as well as deck areas along the entire length and beam of the ship above the mentioned premises.

33 For ships constructed on or after 1 October 1994, the following definition applies instead of the definition of main vertical zones given in paragraph 9:

"The main vertical zones are zones into which the hull, superstructure and deckhouses of the ship are divided by class "A" floors, the average length and width of which on any deck does not exceed, as a rule, 40 m,"

34 "Ro-ro passenger ship" is a passenger ship with cargo spaces with horizontal way loading and unloading or with special category premises defined in this rule.

34 Code of Fire Test Procedures means the International Code of Application of Fire Test Procedures adopted by the Organization's Maritime Safety Committee in resolution MSC.61(67). as may be amended by the organization, provided that such amendments are adopted, come into force and have effect in accordance with the provisions of Article VIII of this Convention relating to amendment procedures applicable to the Annex other than Chapter I thereof.

Rule 4

Fire pumps, fire lines, taps and hoses

(Paragraphs 3.3.2.5 and 7.1 of this rule apply to ships constructed on or after 1 February 1992)

1 Every ship shall be provided with fire pumps, fire mains, cocks and hoses complying, as far as applicable, with the requirements of this regulation.

2 Fire pump performance

2.1 The required fire pumps must supply water to fight a fire under pressure specified in paragraph 4 in the following quantities:

1 pumps on passenger ships - at least two-thirds of the amount provided by bilge pumps when pumping water from holds; And

2 pumps on cargo ships, other than any emergency pump, not less than four-thirds of the quantity provided by each independent bilge pump in accordance with regulation II-1/21 when pumping water from holds on a passenger ship of the same size; however, the total required fire pump capacity on any cargo ship need not exceed 180 m3/h.

2.2 The capacity of each of the required fire pumps (other than any emergency pump required by paragraph 3.3.2 for cargo ships) shall be not less than 80% of the total required capacity divided by the minimum number of fire pumps required, but in no case less than 25 m^3 /h, each such pump must in any case supply at least two jets of water. These fire pumps must supply water to the fire main under the required conditions. If the number of pumps installed exceeds the required minimum number, the capacity of additional pumps shall be as required by the Administration.

3 Measures related to fire pumps and fire mains

3.1 Ships must be equipped with fire pumps with independent drives in the following quantities:

	passenger		at least 3
		capacity
4000 reg.t and more
	passenger		at least 2
		capacity
less than 4000 reg.t and at
cargo
with a capacity of 1000 reg.t and

on cargo ships gross			according to requirements
capacity less than 1000			Administration

3.2 Sanitary, ballast, and bilge pumps or general purpose pumps may be considered fire pumps provided that they are not normally used for the transfer of fuel, and if they are occasionally used for the transfer or transfer of fuel, appropriate switching devices must be provided.

3.3 The location of receiving seawalls, fire pumps and their energy sources must be such that:

1 on passenger ships with a gross tonnage of 1000 gross tonnage or more, a fire in any compartment could not disable all fire pumps;

2 in cargo ships of 2,000 gross tonnage and above, if a fire in any compartment is likely to destroy all pumps, there is another means available consisting of a permanently driven, independently driven emergency pump which shall supply two jets of water as required Administration. This pump and its location must meet the following requirements:

2.1 the pump capacity must be at least 40% of the total fire pump capacity required by this regulation, and in any case not less than 25 m^3/h;

2.2 in the event that the pump supplies the amount of water required by paragraph 3.3.2.1, the pressure in any tap must be not less than the minimum specified in paragraph 4.2;

2.3 Any diesel-powered power source feeding a pump must be capable of being easily started manually from a cold state, down to a temperature of 0°C. If this is not practicable or if it is expected that more low temperatures, it is necessary to consider the possibility of installing and operating heating means acceptable to the Administration to ensure rapid start-up. If manual starting is impracticable, the Administration may permit the use of other means of starting. These means must be such that the diesel power source can be started at least 6 times within 30 minutes and at least twice within the first 10 minutes;

2.4 any service fuel tank must contain a sufficient amount of fuel to ensure that the pump can operate at full load for at least 3 hours; outside the main machinery room there must be sufficient fuel reserves to ensure that the pump operates at full load for an additional 15 hours.

2.5 under conditions of list, trim, roll and pitch that may occur during operation, the total suction lift and net positive suction lift of the pump must be such that the requirements of paragraphs 3.3.2, 3.3.2.1, 3.3.2.2 and 4.2 of this are met rules;

2.6 the structures enclosing the room in which the fire pump is located must be insulated to a standard of structural fire protection equivalent to that required by regulation II-2/44 for the control room;

2.7 it is not allowed to have access directly from the machinery space to the room in which the emergency fire pump and its energy source are located. In cases where this is not practicable, the Administration may permit an arrangement in which access is through a vestibule, both doors of which are self-closing, or through a watertight door, which can be operated from the room containing the emergency fire pump and which is likely not will be cut off in the event of a fire in these premises. In such cases, a second means of access to the room containing the emergency fire pump and its power source must be provided;

2.8 ventilation of the room in which there is an independent source of energy for the emergency fire pump must

prevent, so far as is practicable, the possibility of smoke entering or being drawn into the space in the event of a fire in the machinery space;

2.9 ships built on or after 1 October 1994, in lieu of the provisions of paragraph 3.3.2.6, must meet the following requirements:

the room in which the fire pump is located should not be adjacent to the boundaries of machinery spaces of category A or to those spaces in which the main fire pumps are located. Where the above is not practicable, the common bulkhead between the two spaces shall be insulated to a standard of structural fire protection equivalent to that required for control rooms in regulation 44.

3 in passenger ships of less than 1,000 gross tonnage and in cargo ships of less than 2,000 gross tonnage, where a fire in any compartment is likely to render all pumps inoperable, there are other means of supplying water to combat the fire to the satisfaction of the Administration;

3.1 For ships constructed on or after 1 October 1994, the alternative means provided in accordance with the provisions of paragraph 3.3.3 shall be an independently powered emergency fire pump. The pump's power source and the pump's seacock must be located outside the machine room.

4 In addition, in cargo ships on which other pumps, such as general purpose pumps, bilge pumps, ballast pumps, etc., are located in the machinery space, provisions have been made to ensure that at least one of these pumps having capacity and pressure required by paragraphs 2.2 and 4.2, could supply water to the fire main.

3.4 Measures to ensure constant availability of water supply should:

1 for passenger ships of 1,000 gross tonnage and above, be such that at least one effective stream of water can be immediately supplied from any fire hydrant in the interior spaces and that a continuous supply of water is ensured by the automatic starting of the required fire pump;

2 for passenger ships of less than 1000 gross tonnage and for cargo ships to meet the requirements of the Administration;

3 for cargo ships, when their machinery spaces undergo intermittent unattended maintenance or when only one person is required to keep a watch, provide an immediate supply of water from fire main under appropriate pressure or by remote start one of the main fire pumps from the navigation bridge and

With control post for fire extinguishing systems, if any, or by constant maintenance pressure in the fire main by one of the main fire pumps, except that the Administration may waive this requirement in cargo ships of less than 1,600 gross tonnage if the access location is in

the machine room makes this unnecessary;

4 for passenger ships where their machinery spaces are periodically unattended in accordance with regulation II-1/54, the Administration shall specify requirements for a fixed water fire extinguishing system for such spaces that are equivalent to those for the system for normally manned machinery spaces.

3.5 If fire pumps are capable of producing pressures greater than those piping, valves and hoses are designed to withstand, all such pumps must have relief valves. The placement and adjustment of such valves should help prevent excessive pressure from occurring in any part of the fire main.

3.6 On tankers, in order to preserve the integrity of the fire main in the event of a fire or explosion, shut-off valves must be installed on it in the bow of the poop in a protected place and on the deck of cargo tanks at intervals of no more than 40 m.

4 Diameter of the fire main and pressure in it

4.1 The diameter of the fire main and its branches must be sufficient for efficient distribution of water with the maximum required supply of two simultaneously operating fire pumps; however, on cargo ships it is sufficient that such a diameter ensures a flow of only 140m^3/h.

4.2 If two pumps simultaneously supply through the barrels specified in paragraph 8 the amount of water specified in paragraph 4.1 through any adjacent taps, then the following minimum pressure must be maintained in all taps:

passenger ships:
gross tonnage
	reg.t and more
gross tonnage
	reg.t and more,
but less than 4000 reg.t
gross tonnage		in accordance with the requirements of the Administration
less than 1000 reg.t
cargo ships:
gross tonnage
	reg.t and more
gross tonnage
	reg.t and more,

4.2.1 Passenger ships built on 1 October. 1994 or after that date, in lieu of the provisions of paragraph 4.2, must meet the following requirements:

if two pumps simultaneously supply water through the trunks and taps specified in paragraph 8 to ensure the supply of the amount of water specified in clause 4.1, then a minimum pressure of 0.4 N/mm^2 must be maintained in all taps for ships with a gross tonnage of 4000 gross tonnage and more and 0.3N/mm^2 for ships with a gross tonnage of less than 4000 gross tonnage.

4.3 The maximum pressure in any valve should not exceed the pressure at which the fire hose can be operated effectively.

5 Number and placement of taps

5.1 The number and placement of taps must be such that at least two streams of water from different taps, one of which is supplied through a single hose, reach any part of the ship usually accessible to passengers or crew during navigation, as well as to any part of any empty vessel. cargo space, any cargo space with a horizontal loading and unloading method or any special category space, and in the latter case, any part of it must be reached by two jets supplied through solid hoses. In addition, such taps should be located at the entrances to the protected premises.

5.2 On passenger ships, the number and placement of cranes in accommodation, service and machinery spaces must be such that fall under the requirements of paragraph 5.1 when all watertight doors and all doors in the bulkheads of the main vertical zones are closed.

5.3 If on a passenger ship the machinery space of category A is provided with access at a lower level from the adjacent propeller shaft tunnel, two taps shall be provided outside the machinery space but close to the entrance to it. If such access is provided from other rooms, then two taps must be provided in one of these rooms at the entrance to the machine room of category “A”. This requirement may not apply if the tunnel or adjacent spaces are not part of the escape route.

6 Pipelines and taps

6.1 For the manufacture of fire mains and valves, materials that easily lose their properties when heated should not be used if they are not properly protected. Pipelines and taps must be located so that fire hoses can be easily connected to them. The location of pipelines and taps must prevent them from freezing. On ships which may carry deck cargo, the location of cranes should be such as to ensure easy access at all times and piping should be routed as far as practicable to avoid the risk of damage by the cargo. If the vessel does not provide a hose and barrel for every crane, complete interchangeability of the connecting heads and barrels must be ensured.

6.2 A valve shall be provided to service each fire hose so that any fire hose can be disconnected while the fire pumps are operating.

6.3 Isolation valves for isolating the section of the fire main located in the machinery space in which the main fire pump or pumps are located from the rest of the fire main shall be installed in an easily accessible and convenient location outside the machinery spaces. The location of the fire main shall be such that, with the isolation valves closed, all the ship's valves, except those located in the above-mentioned machinery space, can be supplied with water from a fire pump located outside the machinery space through pipes passing outside it. As an exception, the Administration may allow short sections of emergency fire pump suction and pressure piping to pass through the machinery space if it is not practicable to route them bypassing the machinery space, provided that the integrity of the fire main is ensured by enclosing the piping in a strong steel casing.

7 Fire hoses

7.1 Fire hoses must be made of wear-resistant material approved by the Administration, and their length must be sufficient to supply a stream of water to any of the rooms in which their use may be required. Fire hoses of wear-resistant material must be provided on ships constructed on or after 1 February 1992, and on ships constructed before 1 February 1992 when replacing existing fire hoses. The maximum length of sleeves must meet the requirements of the Administration. Each hose must be equipped with a barrel and the necessary connecting heads. Hoses, referred to in this chapter as "fire hoses", together with all necessary accessories and tools, must be kept in visible places near taps or connections in constant readiness for use. In addition, in the interior of passenger ships carrying more than 36 passengers, fire hoses must be permanently connected to the valves.

7.2 Vessels must be equipped with fire hoses, the number and diameter of which must meet the requirements of the Administration.

7.3 On passenger ships, at least one fire hose shall be provided for each crane required in paragraph 5, which hoses shall be used only for fire-fighting purposes or for testing the operation of fire extinguishing devices.

What fixed fire extinguishing systems are used on ships?

Fire extinguishing systems on ships include:

●water fire extinguishing systems;

●low and medium expansion foam extinguishing systems;

●volumetric extinguishing systems;

●powder extinguishing systems;

●steam extinguishing systems;

●aerosol extinguishing systems;

Ship premises, depending on their purpose and degree of fire hazard, must be equipped various systems fire extinguishing The table shows the requirements of the Rules of the Register of the Russian Federation for equipping premises with fire extinguishing systems.

Stationary water fire extinguishing systems include systems that use water as the main extinguishing agent:

fire protection water system;
water spray and irrigation systems;
flooding system for individual rooms;
sprinkler system;
deluge system;
water mist or water mist system.

Stationary volumetric extinguishing systems include the following systems:

carbon dioxide extinguishing system;
nitrogen extinguishing system;
liquid extinguishing system (using freons);
volumetric foam extinguishing system;

In addition to fire extinguishing systems, fire warning systems are used on ships, such systems include an inert gas system.

What are the design features of water fire protection system?

The system is installed on all types of ships and is the main one for extinguishing fires, as well as a water supply system for ensuring the operation of other fire extinguishing systems, general ship systems, washing tanks, tanks, decks, for washing anchor chains and hawses.

Main advantages of the system:

Unlimited supplies of sea water;

Cheapness of fire extinguishing agent;

High fire extinguishing ability of water;

High survivability of modern UPS.

The system includes the following main elements:

1. Receiving seawalls in the underwater part of the vessel for receiving water in any operating conditions, incl. roll, trim, roll and pitch.

2. Filters (dirt boxes) to protect pipelines and system pumps from clogging with debris and other waste.

3. Non-return valve, which does not allow the system to empty when the fire pumps are stopped.

4. Main fire pumps with electric or diesel drives for supplying sea water to the fire main to fire hydrants, fire monitors and other consumers.

5. Emergency fire pump with an independent drive for supplying sea water in the event of failure of the main fire pumps with its own seacock, valve, safety valve and control device.

6. Pressure gauges and pressure-vacuum gauges.

7. Fire cocks (end valves) located throughout the vessel.

8. Fire main valves (shut-off, non-return shut-off, secant, shut-off).

9. Fire main pipelines.

10. Technical documentation and spare parts.

Fire pumps are divided into 3 types:

1. main fire pumps installed in machinery spaces;

2. emergency fire pump located outside the machinery spaces;

3. pumps allowed as fire pumps (sanitary, ballast, drainage, public use, unless they are used for pumping oil) on cargo ships.

The emergency fire pump (AFP), its seacock, the receiving branch of the pipeline, the discharge pipeline and shut-off valves are located outside the machine access. The emergency fire pump must be a stationary pump with an independent drive from a power source, i.e. its electric motor must also be powered from an emergency diesel generator.

Fire pumps can be started and stopped both from local posts at the pumps and remotely from the navigation bridge and control room.

What are the requirements for fire pumps?

Vessels are provided with independently driven fire pumps as follows:

●passenger ships with a gross tonnage of 4000 and more must have at least three, less than 4000 - at least two.

●cargo ships of 1000 gross tonnage and more - at least two, less than 1000 - at least two pumps driven by a power source, one of which has an independent drive.

The minimum water pressure in all fire hydrants when two fire pumps are operating should be:

● for passenger ships with a gross tonnage of 4000 and more 0.40 N/mm, less than 4000 – 0.30 N/mm;

● for cargo ships with a gross tonnage of 6000 and more – 0.27 N/mm, less than 6000 – 0.25 N/mm.

The flow rate of each fire pump must be at least 25 m/h, and the total water supply on a cargo ship must not exceed 180 m/h.

Pumps are located in different compartments; if this is not possible, then an emergency fire pump must be provided with its own power source and seacock located outside the room where the main fire pumps are located.

The capacity of the emergency fire pump must be at least 40% of the total capacity of the fire pumps, and in any case not less than the following:

● on passenger ships with a capacity of less than 1000 and on cargo ships with a capacity of 2000 or more - 25 m3/h; And

● on cargo ships with a gross tonnage of less than 2000 – 15 m3/h.

Schematic diagram of a water fire system on a tanker

1 – Kingston highway; 2 – fire pump; 3 – filter; 4 – kingston;

5 – water supply pipeline to fire hydrants located in the aft superstructure; 6 – water supply pipeline to the foam fire extinguishing system;

7 – double fire hydrants on the poop deck; 8 – deck fire main; 9 – shut-off valve for disconnecting the damaged section of the fire main; 10 - double fire hydrants on the forecastle deck; 11 – non-return shut-off valve; 12 – pressure gauge; 13 – emergency fire pump; 14 – clinker valve.

The system construction scheme is linear, powered by two main fire pumps (2) located in the MO and an emergency fire pump (13) APZhN on the tank. At the inlet, the fire pumps are equipped with a kingstone (4), a line filter (dirt box) (3) and a clinker valve (14). A non-return shut-off valve is installed behind the pump to prevent water from draining from the main when the pump stops. A fire valve is installed behind each pump.

From the main line through clinker valves there are branches (5 and 6) into the superstructure, from which fire hydrants and other consumers of sea water are supplied.

The fire main is laid on the cargo deck and has branches every 20 meters to dual fire hydrants (7). On the main pipeline, secant fire mains are installed every 30-40 m.

According to the Maritime Register Rules, portable fire nozzles with a spray diameter of 13 mm are mainly installed in interior spaces, and 16 or 19 mm on open decks. Therefore, fire hydrants (hydrates) are installed with D of 50 and 71 mm, respectively.

On the forecastle and poop decks in front of the wheelhouse, twin fire hydrants (10 and 7) are installed on the side.

When the ship is moored in port, the fire water system can be supplied from the international shore connection using fire hoses.

How do water spray and irrigation systems work?

The water spray system in special category rooms, as well as in machine rooms of category A of other ships and pumping rooms, must be powered by an independent pump, which automatically turns on when the pressure in the system drops, from the water fire main.

In other protected premises, the system may only be powered from the fire water main.

In special category spaces, as well as in machinery spaces of category A of other ships and pumping rooms, the water spray system must be constantly filled with water and be under pressure up to the distribution valves on the pipelines.

Filters must be installed on the receiving pipe of the pump feeding the system and on the connecting pipeline with the water fire main to prevent clogging of the system and nozzles.

Distribution valves must be located in easily accessible places outside the protected area.

In protected rooms with permanent occupancy, remote control of distribution valves from these rooms must be provided.

Water spray system in the machine and boiler room

1 – roller drive bushing; 2 – drive roller; 3 - drain valve of the impulse pipeline; 4 – upper water spray pipeline; 5 – impulse pipeline; 6 – quick-acting valve; 7 – fire main; 8 – lower water spray pipeline; 9 – spray nozzle; 10 – drain valve.

Sprayers in protected areas must be placed in the following places:

1. under the ceiling of the room;

2. in the mines of machinery spaces of category A;

3. on equipment and mechanisms whose operation involves the use of liquid fuel or other flammable liquids;

4. over surfaces on which liquid fuel or flammable liquids may spread;

5. over stacks of bags of fishmeal.

Sprayers in the protected area must be located in such a way that the coverage area of any sprayer overlaps the coverage areas of adjacent sprayers.

The pump may be driven by an independent internal combustion engine, located so that a fire in the protected space does not affect the air supply to it.

This system allows you to extinguish a fire in the Ministry of Defense under the slans using lower water spray nozzles or, at the same time, upper water spray nozzles.

How does a sprinkler system work?

Passenger ships and cargo ships are equipped with such systems according to the IIC protection method for signaling a fire and automatic fire extinguishing in protected premises in the temperature range from 68 0 to 79 0 C, in dryers at a temperature exceeding the maximum temperature in the overhead area of no more than 30 0 C and in saunas up to 140 0 C inclusive.

The system is automatic: when the maximum temperature in the protected premises is reached, depending on the area of the fire, one or more sprinklers (water spray) are automatically opened, fresh water is supplied through it for extinguishing, when its supply runs out, the fire extinguishing will continue with sea water without the intervention of the ship’s crew.

General scheme sprinkler system

1 – sprinklers; 2 – water main; 3 – distribution station;

4 – sprinkler pump; 5 – pneumatic tank.

Schematic diagram of a sprinkler system

The system consists of the following elements:

Sprinklers grouped into separate sections of no more than 200 each;

Main and sectional control and signaling devices (KSU);

Fresh water block;

Sea water block;

Panels for visual and audio signals when sprinklers are activated;

Sprinklers – these are closed-type sprayers, inside of which are located:

1) sensitive element - a glass flask with a volatile liquid (ether, alcohol, gallon) or a low-melting Wood's alloy lock (insert);

2) a valve and diaphragm that close the hole in the sprayer for supplying water;

3) socket (divider) for creating a water torch.

Sprinklers must:

Trigger when the temperature rises to preset values;

Be resistant to corrosion when exposed to sea air;

Installed in the upper part of the room and placed so as to supply water to the nominal area with an intensity of at least 5 l/m2 per minute.

Sprinklers in residential and service premises must operate in the temperature range of 68 - 79 ° C, with the exception of sprinklers in drying and galley rooms, where the response temperature can be increased to a level exceeding the temperature at the ceiling by no more than 30 ° C.

Control and alarm devices (KSU ) are installed on the supply pipeline of each sprinkler section outside the protected premises and perform the following functions:

1) sound an alarm when sprinklers are opened;

2) open water supply paths from water supply sources to operating sprinklers;

3) provide the ability to check the pressure in the system and its performance using a test (bleed) valve and control pressure gauges.

Fresh water block maintains pressure in the system in the area from the pressure tank to the sprinklers in standby mode, when the sprinklers are closed, as well as supplying the sprinklers with fresh water during the period when the sprinkler pump of the seawater unit is started.

The block includes:

1) Pressure pneumatic hydraulic tank (NPHTS) with a water meter glass, with a capacity for two water reserves equal to two capacities of the sprinkler pump of the seawater unit in 1 minute for simultaneous irrigation of an area of at least 280 m2 at an intensity of at least 5 l/m2 per minute.

2) Means to prevent sea water from entering the tank.

3) Means for supplying compressed air to the NPGC and maintaining such air pressure in it that, after using up the constant supply of fresh water in the tank, would provide a pressure not lower than the operating pressure of the sprinkler (0.15 MPa) plus the pressure of the water column measured from the bottom tanks to the highest located sprinkler system (compressor, pressure reducing valve, compressed air cylinder, safety valve, etc.).

4) A sprinkler pump to replenish the supply of fresh water, which turns on automatically when the pressure in the system drops, before the constant supply of fresh water in the pressure tank is completely used up.

5) Pipelines made of galvanized steel pipes located under the ceiling of the protected premises.

Sea water block supplies sea water to the sprinklers that open after the sensitive elements are activated to irrigate the premises with a spray jet and extinguish the fire.

The block includes:

1) Independent sprinkler pump with pressure gauge and piping system for continuous automatic supply of sea water to the sprinklers.

2) A test valve on the discharge side of the pump with a short outlet pipe having an open end to allow water flow at the pump capacity plus the water column pressure measured from the bottom of the pumping station to the highest sprinkler.

3) Kingston for independent pump.

4) A filter for cleaning sea water from debris and other objects in front of the pump.

5) Pressure switch.

6) Pump start relay, which automatically turns on the pump when the pressure in the sprinkler power system drops before the constant supply of fresh water in the NPGC is completely consumed.

Visual and audio panels about the activation of sprinklers are installed on the navigation bridge or in the central control room with a constant watch, and in addition, visual and audio signals from the panel are output to another location to ensure that the crew immediately receives a fire signal.

The system must be filled with water, but small external areas may not be filled with water if this is the case. necessary measure precautions at low temperatures.

Any such system must always be ready for immediate operation and be activated without any intervention by the crew.

How does the deluge system work?

Used to protect large areas of decks from fire.

Diagram of the deluge system on a RO-RO vessel

1 – spray head (drenchers); 2 – highway; 3 - distribution station; 4 – fire or deluge pump.

The system is not automatic; it irrigates large areas at the same time with water from deluges at the choice of the team, uses sea water for extinguishing, and is therefore in an empty state. Drenchers (water sprayers) have a design similar to sprinklers but without a sensitive element. It is supplied with water from a fire pump or a separate deluge pump.

How does the foam extinguishing system work?

The first fire extinguishing system using air-mechanical foam was installed on the Soviet tanker Absheron with a deadweight of 13,200 tons, built in 1952 in Copenhagen. On the open deck, for each protected compartment, the following was installed: a stationary air-foam barrel (foam monitor or monitor barrel) of low expansion, a deck main (pipeline) for supplying the foam concentrate solution. A branch equipped with a remotely controlled valve was connected to each trunk of the deck main. The foaming agent solution was prepared in 2 foam extinguishing stations bow and stern and supplied to the deck main. Fire hydrants were installed on the open deck to supply the PO solution through foam hoses to portable air-foam nozzles or foam generators.

foam extinguishing stations

Foam extinguishing system

1 – kingston; 2 – fire pump; 3 – fire monitor; 4 – foam generators, foam barrels; 5 – highway; 6 – emergency fire pump.

3.9.7.1. Basic requirements for foam extinguishing systems. The productivity of each monitor must be at least 50% of the design productivity of the system. The length of the foam jet must be at least 40 m. The distance between adjacent monitors installed along the tanker should not exceed 75% of the flight range of the foam jet from the gun in the absence of wind. Twin fire hydrants are evenly installed along the ship at a distance of no more than 20 m from each other. A shut-off valve must be installed in front of each monitor.

To increase the survivability of the system, cutting valves are installed on the main pipeline every 30–40 meters, with the help of which the damaged section can be disconnected. To increase the tanker's survivability in case of fire in the cargo area, two fire monitors are installed on the deck of the first tier of the aft deckhouse or superstructure and dual fire hydrants are installed to supply solution to portable foam generators or guns.

The foam extinguishing system, in addition to the main pipeline laid along the cargo deck, has branches into the superstructure and into the MO, which end with fire foam valves (foam hydrants), from which portable air-foam nozzles or more efficient portable foam generators of medium expansion can be used.

Almost all cargo ships combine two water fire extinguishing systems and a foam fire extinguishing pipeline in the cargo area by laying these two pipelines in parallel and branches from them to combined foam-water fire monitors. This significantly increases the survivability of the vessel as a whole and the ability to use the most effective fire extinguishing agents depending on the class of fire.

Stationary foam extinguishing system with main consumers

1 - fire monitor (on the VP); 2 - foaming heads (indoors); 3 - medium-expansion foam generator (at the VP and indoors);

4 - manual foam barrel; 5 - mixer

The foam extinguishing station is an integral part of the foam extinguishing system. Purpose of the station: storage and maintenance of foam concentrate (FO); replenishment of supplies and unloading of software, preparation of a foaming agent solution; flushing the system with water.

The foam extinguishing station includes: a tank with a supply of software, a sea water supply pipeline (very rarely fresh water), a software recycling pipeline (mixing software in the tank), a software solution pipeline, fittings, instrumentation, and a dosing device. It is very important to maintain a constant percentage

PO – water ratio, because The quality and quantity of foam depends on this.

What are the steps to use the foam station?

LAUNCH OF FOAM STATION

1. OPEN VALVE “B”

2. START THE FIRE PUMP

3. OPEN VALVES “D” and “E” 4. START FOAM AGENT PUMP

(BEFORE CHECKING THAT VALVE “C” IS CLOSED)

5. OPEN THE VALVE TO THE FOAM MONITOR (OR FIRE HYDRANT),

AND START STEWING

FIRE.

EXTINGUISHING BURNING OIL

1. Never direct the foam jet directly at burning oil, as this may cause burning oil to splash and spread the fire.

2. The foam jet must be directed so that the foam mixture “floats” onto the burning oil layer by layer and covers the burning surface. This can be done by taking advantage of the prevailing wind direction or the slope of the deck where possible.

3. You need to use one monitor and/or two foam barrels

Foam extinguishing station fire monitor

Stationary volumetric foam extinguishing systems are designed to extinguish fires in military buildings and other specially equipped premises by supplying them with high- and medium-expansion foam.

What are the design features of a medium-rate foam extinguishing system?

Medium expansion foam extinguishing uses several medium expansion foam generators permanently installed in the upper part of the room. Foam generators are installed above the main sources of fire, often on different levels MO to cover as much of the extinguishing area as possible. All foam generators or their groups are connected to a foam extinguishing station located outside the protected premises by pipelines of the foam concentrate solution. The principle of operation and design of the foam extinguishing station is similar to the conventional foam extinguishing station discussed earlier.

Disadvantages of the dyna system:

Relatively low expansion rate of air-mechanical foam, i.e. less fire extinguishing effect compared to high expansion foam;

Higher foam concentrate consumption; compared to high expansion foam;

Failure of electrical equipment and automation elements after using the system, because the foaming agent solution is prepared using sea water (the foam becomes electrically conductive);

A sharp decrease in the foam expansion rate when hot combustion products are ejected by a foam generator (at a gas temperature of ≈130 0 C, the foam expansion rate decreases by 2 times, at 200 0 C – by 6 times).

Positive indicators:

Simplicity of design; low metal consumption;

Use of a foam extinguishing station designed to extinguish fires on the cargo deck.

This system reliably extinguishes fires on mechanisms, engines, spilled fuel and oil on floors and under them, but practically does not extinguish fires and smoldering in the upper parts of bulkheads and on the ceiling, thermal insulation of pipelines and burning insulation of electrical consumers due to the relatively small layer of foam.

Diagram of a medium volumetric foam extinguishing system

What are the design features of a volumetric fire extinguishing system with high expansion foam?

This fire extinguishing system is much more powerful and efficient than the previous medium-extinguishing system, because uses more effective high-expansion foam, which has a significant fire extinguishing effect, fills the entire room with foam, displacing gases, smoke, air and vapors of combustible materials through a specially opened skylight or ventilation closures.

The foaming solution preparation station uses fresh or desalinated water, which significantly improves foaming and makes it non-conductive. To obtain high-expansion foam, a more concentrated solution of PO is used than in other systems, approximately 2 times. To obtain high-expansion foam, stationary high-expansion foam generators are used. Foam is supplied into the room either directly from the generator outlet or through special channels. The channels and the outlet from the supply cover are made of steel and must be hermetically sealed to prevent fire from entering the fire extinguishing station. The lids open automatically or manually simultaneously with the supply of foam. Foam is fed into the MO at platform levels in places where there are no obstacles to the spread of foam. If there are fenced-off workshops or storerooms inside the MO, then their bulkheads must be designed in such a way that foam gets into them, or it is necessary to connect separate valves to them.

Schematic diagram for obtaining thousandfold foam

Schematic diagram of volumetric fire extinguishing with high-expansion foam

1 - Fresh water tank; 2 - Pump; 3 - Tank with foaming agent;

4 – electric fan; 5 - Switching device; 6 - Skylight; 7 - Foam supply blinds; 8 - Upper closure of the channel for releasing foam onto the deck; 9 - Throttle washer;

10 - Foaming mesh for high-expansion foam foam generator

If the area of the room exceeds 400 m2, then it is recommended to introduce foam in at least 2 places located in opposite parts of the room.

To check the operation of the system, a switching device (8) is installed in the upper part of the channel, which diverts the foam outside the room to the deck. The supply of foam concentrate for replacing systems should be five times to extinguish a fire in the largest room. The performance of foam generators should be such that it fills the room with foam in 15 minutes.

High-expansion foam is produced in generators with forced air supply to a foam-forming mesh wetted with a foaming agent solution. An axial fan is used to supply air. To apply the foam solution to the mesh, centrifugal sprayers with a swirl chamber are installed. Such sprayers are simple in design and reliable in operation; they have no moving parts. Generators GVPV-100 and GVGV-160 are equipped with one sprayer, other generators have 4 sprayers each installed in front of the tops of pyramidal foam-forming meshes.

Purpose, design and types of carbon dioxide extinguishing systems?

Carbon dioxide fire extinguishing as a volumetric method began to be used in the 50s of the last century. Until this time, steam extinguishing was very widely used, because Most of the ships were equipped with steam turbine power plants. Carbon dioxide fire extinguishing does not require any type of ship's energy to operate the installation, i.e. it is completely autonomous.

This fire extinguishing system is designed to extinguish fires in specially equipped, i.e. secured premises (MO, pump rooms, paint storerooms, storerooms with flammable materials, cargo rooms mainly on dry cargo ships, cargo decks on RO-RO ships). These rooms must be sealed and equipped with pipelines with sprayers or nozzles for supplying liquid carbon dioxide. In these premises, sound (howlers, bells) and light (“Go away! Gas!”) warning alarms are installed to indicate the activation of the volumetric fire extinguishing system.

System composition:

Carbon dioxide fire extinguishing station, where carbon dioxide reserves are stored;

A minimum of two launch stations for remote activation of the fire extinguishing station, i.e. for releasing liquid carbon dioxide into a specific room;

A ring pipeline with nozzles under the ceiling (sometimes at different levels) of the protected premises;

Sound and light alarms warning the crew when the system is activated;

Elements of the automation system that turn off the ventilation in this room and shut off the quick-closing valves for the fuel supply to the operating main and auxiliary mechanisms to stop them remotely (for MO only).

There are two main types of carbon dioxide fire extinguishing systems:

High pressure system - storage of liquefied CO 2 is carried out in cylinders at a design (filling) pressure of 125 kg/cm 2 (filling with carbon dioxide 0.675 kg/l of cylinder volume) and 150 kg/cm 2 (filling 0.75 kg/l);

Low pressure system - the estimated amount of liquefied CO 2 is stored in a tank at an operating pressure of about 20 kg/cm 2, which is ensured by maintaining the CO 2 temperature at about minus 15 0 C. The tank is served by two autonomous refrigeration units to maintain negative temperature CO 2 in the tank.

What are the design features of a high-pressure carbon dioxide extinguishing system?

CO 2 extinguishing station is a separate heat-insulated room with powerful forced ventilation located outside the protected premises. Double rows of 67.5 liter cylinders are installed on special stands. The cylinders are filled with liquid carbon dioxide in an amount of 45 ± 0.5 kg.

The cylinder heads have quick-opening valves (full flow valves) and are connected by flexible hoses to the manifold. The cylinders are grouped into batteries of cylinders using a single manifold. This number of cylinders should be enough (according to calculations) to extinguish a certain volume. In a CO 2 extinguishing station, several groups of cylinders can be grouped to extinguish fires in several rooms. When the cylinder valve is opened, the gaseous phase of CO 2 displaces liquid carbon dioxide through the siphon tube into the collector. A safety valve is installed on the manifold, releasing carbon dioxide when the maximum CO 2 pressure is exceeded outside the station. A shut-off valve for supplying carbon dioxide to the protected area is installed at the end of the collector. This valve is opened either manually or by compressed air (or CO 2 or nitrogen) remotely from the starting cylinder (the main control method). Opening the valves of CO 2 cylinders into the system is done:

The valves of the heads of a number of cylinders are opened manually using a mechanical drive (outdated design);

Using a servomotor, which is capable of opening a large number of cylinders;

Manually by releasing CO 2 from one cylinder into the launch system of a group of cylinders;

Remotely using carbon dioxide or compressed air from a launch cylinder.

The CO 2 extinguishing station must have a device for weighing cylinders or instruments for determining the liquid level in the cylinder. By level of liquid phase CO 2 and temperature environment you can determine the weight of CO 2 from tables or graphs.

What is the purpose of the launch station?

Launch stations are installed outdoors and outside the CO 2 station. It consists of two starting cylinders, instrumentation, pipelines, fittings, and limit switches. Launch stations are mounted in special cabinets that are locked with a key; the key is located next to the cabinet in a special case. When the cabinet doors are opened, the limit switches are activated, which turn off the ventilation in the protected room and supply power to the pneumatic actuator (the mechanism that opens the CO 2 supply valve to the room) and to the sound and light alarm. The scoreboard lights up in the room "Leave! Gas!" or the blue flashing lights come on and an audible signal is given by a bellow or loud bell. When the valve of the right starting cylinder is opened, compressed air or carbon dioxide is supplied to the pneumatic valve and the CO 2 supply to the corresponding room is opened.

How to turn on a carbon dioxide fire extinguishing system for a pumpmain and engine rooms.

2. ENSURE THAT ALL PEOPLE LEAVE THE PUMP COMPARTMENT, PROTECTED BY THE CO2 SYSTEM.

3. SEAL THE PUMP COMPARTMENT.

6. SYSTEM IN WORK.

1. OPEN THE DOOR OF THE START CONTROL CABINET.

2. ENSURE THAT ALL PERSONS HAVE LEFT THE ENGINE ROOM PROTECTED BY THE CO2 SYSTEM.

3. SEAL THE ENGINE COMPARTMENT.

4. OPEN THE VALVE ON ONE OF THE STARTING CYLINDERS.

5. OPEN VALVES No. 1 And No. 2

6. SYSTEM IN WORK.

3.9.10.3. COMPOSITION OF THE SHIP SYSTEM.

Carbon dioxide extinguishing system

1 – valve for supplying CO 2 to the collecting manifold; 2 – hose; 3 - blocking device;

4 – non-return valve; 5 – valve for supplying CO 2 to the protected area

Diagram of the CO 2 system of a separate small room

What are the design features of a low-pressure carbon dioxide extinguishing system?

Low pressure system - the calculated amount of liquefied CO 2 is stored in a tank at an operating pressure of about 20 kg/cm 2, which is ensured by maintaining a CO 2 temperature of about minus 15 0 C. The tank is served by two autonomous refrigeration units (cooling system) to maintain a negative CO 2 temperature in the tank.

The tank and the sections of pipelines connected to it, filled with liquid carbon dioxide, have thermal insulation that prevents pressure from increasing below the setting of the safety valves within 24 hours during a blackout of the refrigeration unit at an ambient temperature of 45 0 C.

The tank for storing liquid carbon dioxide is equipped with a remote liquid level sensor, two control valves for the liquid level of 100% and 95% of the calculated filling. The emergency warning system sends light and sound signals to the control room and mechanics' cabins in the following cases:

When the maximum and minimum (at least 18 kg/cm 2) pressures are reached in the tank;

When the CO 2 level in the tank decreases to the minimum permissible 95%;

In case of malfunction in refrigeration units;

When starting CO 2.

The system is started from remote posts from carbon dioxide cylinders, similar to the previous high-pressure system. The pneumatic valves open and carbon dioxide is supplied to the protected area.

How does a volumetric chemical extinguishing system work?

In some sources, these systems are called liquid extinguishing systems (LES), because The principle of operation of these systems is to supply the fire extinguishing liquid halon (freon or freon) to the protected premises. These liquids evaporate at low temperatures and turn into gas, which inhibits the combustion reaction, i.e. are combustion inhibitors.

The freon supply is located in steel tanks of the fire extinguishing station, which is located outside the protected premises. In protected (guarded) premises, under the ceiling there is a ring pipeline with tangential type sprayers. Sprayers spray liquid refrigerant and, under the influence of relatively low room temperatures from 20 to 54 o C, it turns into gas, which easily mixes with gas environment indoors, penetrates into the most remote parts of the room, i.e. is also able to combat the smoldering of flammable materials.

Freon is forced out of the tanks using compressed air stored in separate cylinders outside the extinguishing station and the guarded room. When the refrigerant supply valves are opened, a sound and light warning alarm is triggered. You must leave the premises!

What is the general structure and principle of operation of the stationary system powder fire extinguishing?

Vessels intended to carry liquefied gases in bulk must be equipped with dry chemical powder extinguishing systems to protect the cargo deck as well as all loading areas at the bow and stern of the ship. It should be possible to supply powder to any part of the cargo deck using at least two monitors and (or) hand guns and hoses.

The system is driven by an inert gas, usually nitrogen, from cylinders located close to where the powder is stored.

It is necessary to ensure the presence of at least two independent, autonomous powder extinguishing installations. Each such installation must have its own controls, high pressure gas, piping, monitors, and hand guns/hoses. On ships with a capacity of less than 1000 r.t., one such installation is sufficient.

Protection of the areas around the loading and unloading manifolds should be provided by a monitor, either locally or remotely controlled. If from its fixed position the monitor covers the entire area protected by it, then it does not require remote targeting. At least one hand sleeve, gun or monitor should be provided at the rear end of the cargo area. All arms and monitors should be capable of being actuated on the arm reel or monitor.

The minimum permissible feed for the monitor is 10 kg/s, and for the hand sleeve - 3.5 kg/s.

Each container must contain enough powder to supply all monitors and hand arms connected to it for 45 seconds.

What is the principle of working withAerosol fire extinguishing systems?

The aerosol fire extinguishing system refers to volumetric fire extinguishing systems. Extinguishing is based on chemical inhibition of the combustion reaction and dilution of the flammable environment with a dusty aerosol. Aerosol (dust, smoke fog) consists of tiny particles suspended in the air, produced by the combustion of a special discharge of a fire extinguishing aerosol generator. The aerosol floats in the air for about 20 minutes and during this time affects the combustion process. It is not dangerous to humans, does not increase the pressure in the room (a person does not receive a pneumatic shock), and does not damage ship equipment and electrical mechanisms that are under voltage.

The ignition of the fire extinguishing aerosol generator (for igniting the charge with a squib) can be set manually or by applying an electrical signal. When the charge burns, the aerosol exits through the cracks or windows of the generator.

These fire extinguishing systems were developed by JSC NPO "Kaskad" (Russia), they are new, fully automated, do not require large installation and maintenance costs, and are 3 times lighter than carbon dioxide systems.

System composition:

Fire extinguishing aerosol generators;

System and alarm control panel (SCUS);

A set of sound and light alarms in a protected area;

Ventilation and fuel supply control unit for MO engines;

Cable routes (connections).

When detecting signs of fire in the premises, automatic detectors send a signal to the control panel, which issues a sound and light signal to the central control room, control center (bridge) and to the protected room, and then supplies power to: stop ventilation, block the fuel supply to the mechanisms to stop them and ultimately to activate fire extinguishing aerosol generators. Different types of generators are used: SOT-1M, SOT-2M,

SOT-2M-KV, AGS-5M. The type of generator is selected depending on the size of the room and the materials being burned. The most powerful SOT-1M protects 60 m 3 of space. Generators are installed in places that do not prevent the spread of aerosol.

AGS-5M is manually activated and thrown indoors.

To increase survivability, the power supply unit is powered from different sources power supply and batteries. The control panel can be connected to a unified computer fire extinguishing system. When the control panel fails, the generators self-start when the temperature rises to 250 0 C.

How does a water mist extinguishing system work?

The fire extinguishing properties of water can be improved by reducing the size of water droplets .

Water mist extinguishing systems, called "water mist extinguishing systems", use smaller droplets and require less water. Compared to standard sprinkler systems, water mist extinguishing systems have the following advantages:

● Small diameter of pipes, facilitating their installation, minimal weight, lower cost.

●Requires lower capacity pumps.

●Minimum secondary damage associated with the use of water.

● Less impact on vessel stability.

The higher efficiency of an aqueous system operating using small droplets is achieved due to the ratio of the surface area of the water droplet to its mass.

Increasing this ratio means (for a given volume of water) increasing the area through which heat transfer can occur. Simply put, small water droplets absorb heat faster than larger ones and therefore have a greater cooling effect on the fire zone. However, excessively small droplets may not reach their destination because they do not have enough mass to overcome the warm air currents generated by the fire. Water mist extinguishing systems reduce the oxygen content in the air and therefore have an asphyxiating effect. But even in enclosed spaces, such action is limited, both due to its limited duration and due to the limited area. When the droplet size is very small and the heat content of the fire is high, which leads to the rapid formation of significant volumes of steam, the suffocating effect is more pronounced. In practice, water mist extinguishing systems provide extinguishing mainly through cooling.

Water mist extinguishing systems should be carefully designed, should provide uniform coverage of the protected area, and, when used to protect specific areas, should be located as close as possible to the relevant potential hazard area. In general, the design of such systems is the same as the previously described sprinkler systems (with “wet” pipes), except that water mist extinguishing systems operate at a higher operating pressure, about 40 bar, and they use specially designed heads that create drops of the required size.

Another advantage of water mist extinguishing systems is that they are excellent at protecting people because small water droplets reflect thermal radiation and bind flue gases. As a result, personnel involved in extinguishing the fire and ensuring evacuation may move closer to the source of the fire.

Welcome reader, in this article you will find everything necessary materials for fire pumps, a menu (content) was specially created to quickly find the necessary information. Additionally, we have collected in the article links to all available data on pumps posted on the project pages.

Instructions for use:

Literature:

Fire equipment third edition, revised and expanded. Edited by Honored Scientist of the Russian Federation, Doctor of Technical Sciences, Professor M.D. Bezborodko Moscow 2004

Definition, classification, general structure, principle of operation and application in fire protection

Pumps– these are machines that convert the supplied energy into the mechanical energy of the pumped liquid or gas.

Purpose of pumps

Of all the variety of fire-fighting equipment, pumps represent the most important and complex type. Fire trucks for various purposes use a diverse range of pumps operating according to various principles. Pumps, first of all, ensure the supply of water for extinguishing fires and the operation of such complex mechanisms as ladder trucks and articulated lifts. Pumps are used in many auxiliary systems, such as vacuum systems, hydraulic elevators, etc. The widespread use of pumps is due not only to their design, but also to their performance characteristics, features of their operating modes, which ensures their effective use for extinguishing fires.

The first mention of pumps dates back to the 3rd – 4th centuries. B.C. At this time, the Greek Ctesibius proposed a piston pump. However, it is not known for sure whether it was used to extinguish fires.

The manufacture of manually driven piston fire pumps was carried out in the 18th century. Fire pumps driven by steam engines were produced in Russia as early as 1893.

The idea of using centrifugal forces to pump water was expressed by Leonardo da Vinci (1452 - 1519), while the theory of a centrifugal pump was substantiated by a member of the Russian Academy of Sciences, Leonhard Euler (1707 - 1783).

Creation centrifugal pumps developed intensively in the second half of the 19th century. In Russia, engineer A.A. was involved in the development of centrifugal pumps and fans. Sablukov (1803 - 1857) and already in 1840 he developed a centrifugal pump. In 1882, a sample of a centrifugal pump was produced for the All-Russian Industrial Exhibition. It supplied 406 buckets of water per minute.

Soviet scientists I.I. made a great contribution to the creation of domestic hydraulic machines, including pumps. Kukolevsky, S.S. Rudnev, A.M. Karavaev et al. Fire centrifugal pumps domestic production were installed on the first fire trucks (PMZ-1, PMG-1, etc.) already in the 30s. last century. Research in the field of fire pumps has been carried out for many years at VNIIPO and VIPTSH. Currently, fire trucks use various types of pumps. They ensure the supply of fire extinguishing agents, the functioning of vacuum systems, and the operation of hydraulic control systems.

The operation of all mechanically driven pumps is characterized by two processes: suction and discharge of the pumped liquid. In this case, a pump of any type is characterized by the amount of fluid supplied, developed by pressure, suction height and the value of the efficiency factor.

Pump delivery is the volume of liquid pumped per unit time Q, l/s.

Pressure pump is the difference between the specific energies of the liquid after and before the pump. Its value is measured in meters of water column, N, m.

where e2 and e1 are the energy at the inlet and outlet of the pump;
Р2 and Р1 – liquid pressure in the pressure and suction cavities, Pa;
ρ – liquid density, kg/m3;
v2 and v1 – fluid velocity at the outlet and inlet to the pump, m/s;
g – free fall acceleration, m/s.

The difference between z2 and z1 is also small, so for practical calculations they are neglected.

In accordance with the figure, the pressure developed by the pump N, must ensure water rises to a height N g, overcome resistance in the suction h sun and pressure line h n and ensure the required pressure on the barrel N st. Then we can write

N =N G + h Sun + h n + N stv

Losses in the suction and pressure lines are determined by the formula

h Sun = S Sun Q2 And h n = S n Q 2

Where S sun and S n – resistance coefficients of suction and discharge lines.

1 – pump; 2 – suction pipe; 3 – collector; 4 – pressure valve; 5 – sleeve line; 6 – trunk

Operating principle of a centrifugal pump

A wheel is installed in the pump housing and rotates freely. When rotating, the wheel blades act on the fluid and impart energy to it, increasing pressure and speed. The flow part of the pump housing is made in the form of a spiral. The pump body is equipped with a flat, removable “tooth” platform, with the help of which water is removed from the pump wheel and directed into the diffuser. As a result of the rotation of the pump wheel, a vacuum (vacuum) appears at the inlet in the suction channel, and gauge (excess) pressure appears at the outlet in the diffuser. Flow separators are provided in the suction cavity of the wheel cover to prevent it from twisting. It is also recommended to make the inlet part of the channel at the entrance to the pump wheel in the form of a confuser, which increases the flow rate at the inlet by 15-20%. The outlet part of the spiral outlet of the housing is made in the form of a diffuser with a cone angle of 8°.

The cross sections of the diffuser are circular. You can make sections other than circular; in this case, the ratios of areas and lengths are chosen by analogy with a diffuser with circular cross sections. Compliance with these recommendations prevents the formation of turbulent fluid movement, reduces hydraulic losses in pumps and increases efficiency. To prevent the flow of liquid from the pressure cavity into the suction cavity, gap seals are provided between the housing and the pump wheel. The design of the gap seals allows for a slight flow of liquid between the cavities, including into the closed cavity between the wheel and the pump housing on the side of the bearing supports. To relieve pressure in this closed cavity, the pump wheel has through holes directed into the suction cavity. The number of holes is equal to the number of wheel blades.

To form a mixture of water and foam, a foam mixer is provided on the pump. Through the foam mixer, part of the water from the pressure manifold is directed into the suction cavity of the pump cover, together with the foam concentrate. The foaming agent can be supplied to the pump either through pipelines from the tank of a fire truck, or from an external tank through a flexible corrugated hose. Dosing (proportional ratio) of foam and water is carried out through holes of different diameters in the dosing disk of the foam mixer. To regulate the supply of water or foam mixture to fire hoses or other consumers, shut-off valves are installed. If necessary, a valve with a pneumatic drive can be installed on the pump to connect devices that require remote activation, such as a fire monitor, feed combs of foam generators of airfield fire trucks, etc.

Positive displacement, jet, centrifugal pumps

Positive displacement pumps

Positive displacement pumps– pumps in which the movement of liquid (or gas) is carried out as a result of periodic changes in the volume of the working chamber.

These include pumps:

piston
plastic
gear
water ring

Piston pumps

In piston pumps, the working element (piston) performs a reciprocating movement in the cylinder, imparting energy to the pumped liquid.

Piston pumps have a number of advantages. They can pump various liquids, creating high pressures (up to 15 MPa), have good suction capacity (up to 7 m) and high efficiencyη = 0.75–0.85.

Their disadvantages are: low speed, uneven fluid supply and the inability to regulate it.

Axial piston pumps

Axial piston pump:

1 – distribution disk; 2 – piston; 3 - drum; 4 – rod; 5 – axis; 6 – shaft; 7 – distribution disc

Several piston pumps 2 placed in one drum 3 rotating on the axis of the distribution disk 1 . Piston rods 4 hinged on a disk rotating on an axis 5 . When the shaft rotates 6 The pistons move axially and simultaneously rotate with the drum. These pumps are used in hydraulic systems and pump oils.

The distribution disk 7 has two crescent-shaped windows. One of them is connected to the oil tank, and the second to the line into which the oil is supplied.

For one revolution of the drum shaft, each piston moves forward and backward (suction and discharge).

Double acting piston pumps

Pumps of this type are used as vacuum pumps on a number of fire pumps manufactured by foreign companies. Pump pistons 5 bolted together 3 into a single whole. They move mounted on an axis 2 eccentric 1 by means of a slider 4 .

1 – eccentric; 2 – axis; 3 – rod connecting the pistons; 4 – slider; 5 – piston; 6 – exhaust pipe; 7 – large membrane; 8 – small membrane; 9 – suction pipe; 10 - frame; 11 - lid

The rotation speed of the eccentric shaft is the same as the rotation speed of the pump shaft. The eccentric shaft is driven by a V-belt from the power take-off. Turning the eccentric 1 sliders 4 act on the pistons 5 . They perform a reciprocating movement. In the position shown in the figure, the left piston will compress the air that previously entered the chamber. Compressed air will overcome the resistance of the cuff 7 and will be removed through the pipe 6 into the atmosphere.

Simultaneously with this, a vacuum will be created in the right chamber. In this case, the resistance of the first small cuff will be overcome 8 . A vacuum will be created in the fire pump and it will gradually fill with water. When water enters the vacuum pump, it turns off.

For each half revolution of the eccentric, the pistons make a stroke equal to 2e. Then the pump flow, m3/min, can be calculated using the formula:

Where d– cylinder diameter, m;
e – eccentricity, m;
n– roller rotation speed, rpm.

At a rotation speed of 4200 rpm, the pump ensures filling of the fire pump from a suction depth of 7.5 m in less than 20 s

Consists of their body 2 and gears 1 . One of them is set in motion, the second, in engagement with the first, rotates freely on an axis. When the gears rotate, the fluid moves in depressions 3 teeth around the circumference of the body.

They are characterized by a constant fluid supply and operate in the range of 500–2500 rpm. Their efficiency, depending on the rotation speed and pressure, is 0.65–0.85. They provide a suction depth of up to 8 m and can develop a pressure of more than 10 MPa. The NShN-600 pump used in fire fighting equipment provides the supply Q= 600 l/min and develops pressure N up to 80 m at n= 1500 rpm.

1 – gear; 2 – body; 3 – depression

The pump flow is determined by the formula, where R And r– radii of gears along the height and tooth cavities, cm; b– gear width, cm; n– shaft rotation speed, rpm; η – efficiency. These pumps are equipped with a bypass valve. When there is excess pressure, liquid flows through it from the discharge cavity into the suction cavity.

Vane (vane) pump

Consists of a body with a sleeve pressed into it 1 . In the rotor 2 steel plates placed 3 . The drive pulley is fixed to the rotor 2 .

Rotor 2 placed in a sleeve 1 eccentric. When the blade rotates 3 under the influence of centrifugal force they are pressed against the inner surface of the sleeve, forming closed cavities. Suction occurs due to a change in the volume of each cavity as it moves from the suction port to the outlet.

1– sleeve; 2 – rotor; 3 – plate

Vane pumps can create pressures of 16–18 MPa and provide water intake from a depth of up to 8.5 m with an efficiency of 0.8–0.85.

The vacuum pump is lubricated by oil, which is supplied to its suction cavity from the oil tank due to the vacuum created by the pump itself.

Liquid ring pump

Can be used as a vacuum pump. The principle of its operation is easy to understand from Fig. 2.8. When the rotor rotates 1 with blades, the liquid is pressed against the inner wall of the pump housing under the influence of centrifugal force 4 . When rotating the rotor from 0 to 180°, the working space 2 will increase and then decrease. As the working volume increases, a vacuum is formed through the opening of the suction channel 3 air will be sucked in. As the volume decreases, it will be pushed out through the discharge port hole 5 into the atmosphere.

A liquid ring pump can create a vacuum of up to 9 m of water column. This pump has a very low efficiency of 0.2-0.27. Before starting work, you need to fill it with water - this is its significant drawback.

1 – rotor; 2 – workspace; 3 – suction channel; 4 - frame; 5 – channel opening

Jet pump

Jet pumps are divided into:

Gas jet;
water jet

Water jet pump– a firefighter hydraulic elevator is included in the fire safety equipment kit of each fire truck. It is used to withdraw water from water sources with a water level exceeding the geodetic suction height of fire pumps. With its help, you can take water from open water sources with swampy banks, which are difficult for fire trucks to access. It can be used as an ejector to remove water spilled when extinguishing fires from premises.

The fire hydraulic elevator is an ejector type device. Water (working fluid) from the fire pump flows through a hose connected to the head 7 , in the knee 1 and further into the nozzle 4 . In this case, the potential energy of the working fluid is converted into kinetic energy. In the mixing chamber, an exchange of momentum occurs between the particles of the working and sucked fluid: when the mixed fluid enters the diffuser 5 the kinetic energy of the mixed and transported liquid is converted into potential energy. Thanks to this, a vacuum is created in the mixing chamber. This ensures the absorption of the supplied liquid. Then, in the diffuser, the pressure of the mixture of working and transported fluids increases significantly as a result of a decrease in movement speed. This allows water injection.

Firefighting hydraulic elevator G-600A

Dependence of hydraulic elevator performance on suction height and pump pressure: 1 – suction height; 2 – water suction range at a suction height of 1.5 m

Gas jet ejector pump

Used in gas-jet vacuum devices. They help ensure that suction hoses and centrifugal pumps are filled with water.

The working fluid of this pump is the exhaust gases of the AC internal combustion engine. They enter the high pressure nozzle, then into the chamber 3 pump housing 2 , into the mixing chamber 4 and diffuser 5 . As in the liquid ejector, in the chamber 3 a vacuum is created. The air ejected from the fire pump ensures the creation of a vacuum in it and, consequently, filling the suction hoses and the fire pump with water.

The pump has two nozzles: small 2 and large 4. A tube b is inserted into the chamber between them, connecting the jet and centrifugal pumps. When diesel exhaust gases enter along arrow a, the large nozzle creates a vacuum in chamber b and air enters it from the pump through tube 3 and is additionally sucked in from the atmosphere (arrow b). This suction helps stabilize the operation of the jet pump. Such jet pumps are used on ACs with the Ural chassis and YaMZ-236 (238) engines.

Classification of centrifugal pumps

by number of impellers: one-; two- and multi-stage;

by shaft location: horizontal, vertical, inclined;

according to the developed pressure: normal up to – 100m, high – 300m and more; combination pumps simultaneously supply water under normal and high pressure;

by location on fire trucks: anterior, middle, posterior.

Schematic diagrams of fire pumps

Schematic diagrams of single (left), double (middle) and differential (right) action piston pumps.

Scheme of a vane (vane) pump.

1 – rotor, 2 – gate, 3 – variable volume, 4 – housing

Schematic diagram of a liquid ring pump

1 – rotor, 2 – volume between the blades, 3 – water ring, 4 – housing, 5 – suction pipe, 6 – discharge pipe

1 – pressure cavity, 2 – driven gear, 3 – suction cavity, 4 – housing, 5 – drive gear

1 – shaft, 2 – impeller, 3 – suction pipe, 4 – pressure pipe, 5 – housing, 6 – spiral chamber

Technical characteristics of pumps used in fire protection

Normal pressure fire pump NTsPN-100/100

Designed for supplying water and aqueous solutions of foaming agents with temperatures up to 303° K (30° C), with a hydrogen index (pH) from 7 to 10.5 and a density of up to 1100 kg/m 3, mass concentration up to 0.5%, with their maximum size 6 mm. It is used to complete fire pumping stations, installation on fire boats and for pumping large volumes of water.

INDICATORS	NORMAL PRESSURE FIRE PUMPS
INDICATORS	NTsPN-100/100 M1 (M2)
TACTICAL, TECHNICAL AND OPERATIONAL CHARACTERISTICS
Nominal flow, l/s	100
Pressure in nominal mode, m	100
	155 (210 hp)
Rated rotation speed of the drive shaft, rpm	2000
	7,5
Pump filling time from the highest geometric suction height, s	40 (no more)
Maximum pump flow at the highest geometric suction height, l/s	50 (not less)
	1…10
Number of simultaneously operating GPS-600, pcs.	16 (at 6% concentration of foam solution)
Weight, kg	360.0 (no more)
Overall dimensions, mm	930x840x1100 (no more)
Service life, years	12 (at least)

Options for pump NTsPN-100/100:

M1 – equipped with two side pressure valves;
M2 - additionally equipped with a central locking device

General view pumping unit NTsPV-4/400-RT and technical characteristics

– pump flow in nominal mode – 0.004 m3/s (4 l/s);
– pump pressure in nominal mode – 400 m.water column;
– power consumption in nominal mode – 35 kW (48 l/s);
– nominal speed of the pump shaft – 6400 rpm;
– pump efficiency – 0.4;
– cavitation (critical) pump reserve – 5 m;
– overall dimensions – 420mm. x 315mm. x 400mm;
– weight (dry) – 35 kg;
– maximum size of solid particles in the working fluid – 3 mm;
– foam agent dosage level when working with one
– barrel – sprayer type SRVD 2/300 – 3, 6, 12%.

General view of the pumping unit NTsPK-40/100-4/400V1T and technical characteristics of NTsPV-4/400

Name of indicators	Meaning of indicators
Name of indicators	NTsPK-40/100-4/400	NTsPV-4/400
Pump flow in nominal mode, m3/s (l/s)	40-4-15/2*	4
Pump pressure in nominal mode, m. water. Art.	100-400-100/400*	2
Power in nominal mode, hp	89-88-100*	36
Rated shaft speed, rpm	2700	6300
Efficiency factor, not less	0,6-0,35-0,215*	0,4
Allowable cavitation reserve, m, no more	3,5	5,0
Vacuum system type	automatic	automatic
Foam dosing system type	automatic	manual
Maximum geometric suction height, m	7,5	–
Suction time from the highest geometric suction height, s, no more	40	–
Overall dimensions, mm, no more than length width height	800800800	420315400
Weight (dry), kg	150	50
Foaming agent dosage level, %	6,0+/- 1,23,0+/- 0,6	6,0+/-1,23,0+/- 0,6

Centrifugal fire pump PN-40UV (left) and its modification PN-40UV.01 with a built-in vacuum system (right)

Characteristics of pumps NTsPN-40/100, PN-40UA, PN-40UB;

Pump type	NTsPN- 40/100	PN-40UA	PN-40UB;
Pump flow in nominal mode, l/s	40	40	40
Pump pressure in nominal mode, MPa (m,v,st,)	1 (100)	1 (100)	1 (100)
Rated shaft rotation speed, min-1	2700	2700	2700
Power consumption in nominal mode, kW	65,4	68	65; 62
Vacuum system type	automatic	gas jet	gas jet
Geometric suction lift, m	7,5	7,0	7,5
Suction time, s	40	45	40
Efficiency	0,6	0,6	0,6
Cavitation reserve, m	3	3	3
Max, pressure at the pump inlet, MPa	0,59	0,4	0,4
Type of dosing device	manual PS-5	manual PS-5	manual PS-5
Number and nominal diameter of suction pipes, pcs./mm	1/125	1/125	1/125

Centrifugal fire pump PN-40UV.01, PN-40UV.02 (PN-60)

The PN-40UV pump is designed for supplying water or aqueous solutions of foaming agent with a temperature of up to 30 C with a pH value of 7 to 10.5, a density of up to 1100 kg*m -3 and a mass concentration of solid particles of up to 0.5% with a maximum size of 3 mm. The pump is used for installation in closed compartments of fire trucks, in which a positive temperature is ensured during operation.

PN40-UV.01 – pump with autonomous system water intake.
PN40-UV.02 – pump with an autonomous water intake system, technical characteristics similar to the PN-60 pump

Indicator name	PN-40UV	PN-40UV-01	PN-40UV-02 (PN-60)
Productivity, m 3 /s (l/s)	0,04 (40)	0,04 (40)	0,06 (60)
Head, m	100+5	100+5	100+5
Power, kW (hp)	62,2 (84,9)	77,8 (106)	91,8 (125)
Maximum geometric suction height, m	—	7,5	7,5
Filling time from the highest geometric suction height, s	—	40	40
Shaft rotation speed, rpm	2700	2700	2800
Largest number of simultaneously operating GPS units, units	5	5	7
Conditional diameter DN of connecting pipes:
pressure	70	70	70
suction	125	125	125
Dimensions, mm	700 x 900 x 700	700 x 900 x 700	700 x 900 x 700
Weight, kg	65	90	90

Centrifugal fire pump PN-40UVM.01, PN-40UVM.E

Fire pumps of the PN-40UVM type are equipped with a seal made of thermally expanded graphite, designed and manufactured specifically for these pumps using nanotechnology, and roller bearings are installed that do not require lubrication throughout the entire life of the pump. The pump is equipped with a set of control and measuring instruments (electronic tachometer, hour meter, pressure gauge, pressure vacuum gauge), an anti-cavitation device is installed, protected by invention patent No. 2305798, the flow part of the pump is improved, allowing it to have a reserve on the main output parameters (flow rate - up to 60 l/s , pressure – up to 120 m, efficiency – up to 70%).

At the request of the customer, a vacuum pump with a mechanical drive (PN-40UVM-01) or with an electric drive (PN-40UVM.E) can be installed on the PN40-UVM pump. The PN-40UVM.E fire pump is available in two versions: with a vacuum system, which is supplied separately from the pump, and in a monoblock version (the vacuum system is installed directly on the pump body).

Tactical and technical characteristics of PN-60 and PN-110

Name of indicators	Dimension	PN-60	PN-110
Pressure	m	100	100
Innings	l/s	60	110
Rotational speed	rpm	2500	1350
Impeller diameter	mm	360	630
Efficiency	–	0,6	0,6
Power consumption	kW	98	150
Maximum suction lift	m
Weight	kg	180	620

Tactical and technical characteristics of NTS-20/160

The NTS-20/160 pump is designed for supplying water and aqueous solutions of foaming agent with a temperature of up to 303°K (30°C), a density of up to 1100 kg/m 3 and a mass concentration of suspended solid soil particles of up to 0.5%, with a maximum size of 3 mm.

Posters for the technical class are available by clicking the “DOWNLOAD” button in high resolution.

Malfunctions, symptoms, causes and solutions

Malfunctions (failures) that occur in pumping units and water-foam communications lead to a disruption in their performance, a decrease in the effectiveness of fire extinguishing and an increase in losses from them.

Work failures pumping units arise due to a number of reasons:

firstly, they may appear as a result of incorrect actions by drivers when turning on water and foam communications. The probability of failures for this reason is lower, the higher the level of qualification of combat crews;
secondly, they appear due to wear of the working surfaces of parts. Failures for these reasons are inevitable (you need to know them and be able to evaluate them in a timely manner);
thirdly, violations of the tightness of connections and associated fluid leaks from systems, the inability to create a vacuum in the suction cavity of the pump (it is necessary to know the causes of these failures and be able to eliminate them).

Malfunctions of PN pumping units.

Signs of possible malfunctions leading to failures, their causes and solutions are given in the table.

Signs malfunctions	Causes of malfunctions	Remedies
When the vacuum system is turned on, no vacuum is created in the cavity of the fire pump	Air leak: 1. The drain valve of the suction pipe is open, the valves are not seated tightly on the seats of the valves and gate valves, the valves and gate valves are not closed.2. Leaks in connections between the vacuum valve and pump, foam mixer diffuser bowl, vacuum system pipelines, pump seals, plug valve	1. Close all taps, valves, and valves tightly. If necessary, disassemble them and eliminate the malfunction.2. Check the tightness of the connections, tighten the nuts, replace the gaskets if necessary. If the pump seals are worn, replace them

The fire pump first supplies water, then its output decreases. The pressure gauge needle fluctuates greatly	Leaks have appeared in the suction line, hose delamination, the suction mesh is clogged. The impeller channels are clogged. Leaks in the seals of the fire pump	Find leaks and eliminate them, replace the hose, clean the mesh. Disassemble the fire pump, clean the channels. Tighten the oiler cap, replace the seals
The fire pump does not create the required pressure	The impeller channels are partially clogged. Excessive wear of the sealing rings. Air leaks. Damage to the impeller blades.	Disassemble the pump, clean the channels. Disassemble the pump, replace the rings. Eliminate air leaks. Disassemble the pump, replace the wheel
The foam mixer does not supply foam agent	The pipeline from the tank to the foam mixer is clogged. The dispenser holes are clogged.	Disassemble and clean the pipeline. Disassemble the dispenser and clean its holes
Gas siren does not work well, the sound is weakened	The channels of the gas distributor and resonator are clogged. The exhaust pipeline is not completely blocked by the damper	Clean the channels and resonator. Adjust the rod length. Disassemble and clean the valve
Gas siren works after switching off	The damper spring is weakened or broken. The adjustment of the length of the traction elements is disturbed.	Replace the spring. Adjust the rod
The monitor control valve and the valve for water and foam communications do not open when the taps on the column are opened	Low air pressure in the brake system. Connections of valves, taps, pipelines are leaky. The limiting valve is faulty	Increase the pressure in the system. Tighten the fitting nuts, replace the gaskets. Disassemble, fix

Malfunctions of monitoring station pumping units.

Signs malfunctions	Causes of malfunctions	Remedies
1. When the pump is running, the flow rate has decreased, the outlet pressure is below normal	1. The suction mesh is clogged.2. The protective mesh at the pump inlet is clogged3. The pump flow exceeds the permissible flow rate for a given suction lift.4. The impeller channels are clogged	1. Check the suction mesh.2. Check the integrity of the suction mesh, if necessary, clean the protective mesh at the pump inlet.3. Reduce feed (number of working barrels or rotation speed).4. Clear channels
2. There is knocking and vibration when the pump is running.	1. The pump mounting bolts are loose.2. Pump bearings are worn out.3. Foreign objects have entered the pump cavity.4. Impeller damaged	1. Tighten the bolts. 2. Replace worn bearings with new ones. 3. Remove foreign objects.4. Replace impeller
4. Water flows in a trickle from the drainage compartment of the pump.	1. Violation of the tightness of the end shaft seal	1. Replace worn parts (assemblies) of the end seal
5. The dispenser handle does not turn	1. The appearance of crystalline deposits and corrosion products on friction surfaces as a result of poor flushing	1. Disassemble the dispenser, clean the mating surfaces from deposits
6. High oil consumption in the oil bath of the shaft bearings	1. Wear of rubber cuffs	1. Replace cuffs
7. The pump shaft rotates, the tachometer needle is at zero	1. Open circuit of the tachometer	1. Detect and eliminate open circuits
8. When the ejector is turned on and the dispenser is open, the foam agent does not flow into the pump	1. The shut-off valve of the dispenser does not operate due to clogging of the pipeline supplying water to the bellows controlling the valve	1. Clean the pipeline (channel)
9. When the foam mixer is operating, software is not supplied to the pump or its dosage level is insufficient	1. Depressurization of the vacuum system control drive2. Jamming of the spool in the foam mixer valve or clogging of its cavity as a result of poor flushing	1. Find leaks where liquid is leaking, eliminate the leaks, check the vacuum seal diaphragm.2. Disassemble the foam mixer valve and clean its cavity and parts from dirt
10. If there is no water supply, the “No Supply” indicator does not light up	1. Break in power supply circuits.2. The LED (lamp) has burned out.3. The falling valve is jammed in the guide.4. Magneto-electric contact faulty	1. Detect and eliminate.2. Replace the LED (lamp).3. Identify the causes and eliminate jamming.4. Replace magneto-electric contact
11. When the ASD is turned on, the “ASD power” indicator does not light up, the dispenser handle does not move	1. Break in the power supply circuit “fire truck - electronic unit”. 2. Insufficient friction grip tion coupling of the dispenser drive	1. Detect and eliminate an open circuit.2. Adjust the clutch
12. When the ASD is turned on, the dispenser handle does not move, the “ASD power” indicator lights up	1. Break in electrical circuit“electronic unit – electric motor” of the dispenser2. Insufficient adhesion of the friction clutch of the metering drive	1. Detect and repair open circuit2. Adjust couplings
13. When dispensing a foam concentrate in automatic mode, the quality of the foam is unsatisfactory, the dispenser handle does not reach the position corresponding to the number of operating foam generators	1. High hardness of water supplied by the pump	1. Using a corrector, increase the concentration of the foaming agent or switch to manual dosing
14. Increased consumption of foaming agent when dosing in automatic mode, the dispenser handle stops in a position corresponding to more foam generators than are actually connected	1. Contamination of the electrodes of the foam concentrate concentration sensor	1. Clean the electrodes of the concentration sensor
15. When dispensing foam concentrate in automatic mode, the dispenser handle reaches the stop (position “5- 6%"), but the “ASD norm” indicator does not light up, and the dispenser motor continues to rotate	1. The shut-off valve of the dispenser does not open due to clogging of the pipeline supplying water to the bellows controlling the valve.2. If the malfunction appears only when working with a large number of GPS-600 (4- 5 pcs.), the reason is an increase in the hydraulic resistance of the foam concentrate line as a result of its clogging.3. Open circuit “electronic unit - concentration sensor”	1. Clean the pipeline (channel). 2. At the next maintenance, clean the foam concentrate line, including the dispenser cavities. 3. Detect and repair open circuit
16. The operating time counter does not work	1. Open circuit in the power supply between the primary foam concentrate and the electronic unit or between the electronic unit and the indicating device on the panel.2. Electronic unit malfunction3. The operating time counter is faulty	1. Detect and eliminate open circuit.2. Replace or repair the electronic unit. 3. Replace the meter

The PTsNV-4/400 pump does not have a suction system, but its design has two valves: a bypass and a shut-off valve. Faults in them serve to disrupt the normal operation of the pump.

Their list is given in the table:

Signs malfunctions	Causes of malfunctions	Remedies
1. Water flows in a trickle from the pump drain hole.	1. End seal leakage	1. Disassemble the pump, replace worn seal parts
2. When the pump is running, its body becomes very hot.	1. The passage holes in the bypass and shut-off valves are clogged	1. Remove valves, disassemble and troubleshoot
3. Water supply has decreased, the pressure in the pressure manifold is normal	1. Bypass valve jammed	1. Remove the valve, eliminate the fault
4. With the ejector on, the dispenser open and the spray barrel foam agent does not enter the pump	1. The bypass is faulty valve.2. Shut-off valve jammed	1. Remove the valves, eliminate any detected faults
5. Foaming agent dosage level is below normal	1. Clogging of the foam concentrate line, in particular, the flow cavity of the shut-off valve	1. Disassemble and clean all elements of the foam concentrate line

Procedure for operating pumps

Since the fire pump is not self-priming, it must be filled before use. When the pump operates from a fire truck tank, due to the fact that the liquid level in the tank is higher than the pump level, filling is possible by opening the shut-off valves, without creating a vacuum. When operating the pump from an open reservoir, initial filling is necessary using an additional vacuum pump. Therefore, before putting into operation, turn on the vacuum pump. The vacuum pump sucks water into the fire pump, after which the vacuum pump is turned off and the rotation of the fire pump is turned on. When the pump is full, the pump pressure gauge shows excess pressure.

After pressure appears, the valves on the pump are slowly opened and water flows into the pressure fire hoses until a stream without air impurities is obtained. After which, the fire pump is ready for operation. The fire pump works steadily, sucking up water from a height of up to 7.5 m. A further increase in the suction height leads to cavitation, unstable pump operation and, as a rule, jet breakdown. For normal operation of the pump, it is important to ensure the tightness of the internal working cavities. During operation, the pumps are periodically checked for leaks by vacuum. The maximum vacuum value is created and the valve between the main and vacuum pump is closed. It is considered normal if the vacuum drop in 1 minute does not exceed 0.1 kgf/cm2.

The difference between NCPV and PN

The developers have completely preserved the traditional design of the pump, right down to the location of the controls and all the mounting connections, but at the same time achieved a significant improvement in the parameters and eliminated all the known “sores” of the old design.

In particular:

productivity increased 1.5 times (up to 60 l/s when operating from hydrants and up to 50 l/s when operating from reservoirs);
pressure increased by 20% and efficiency by 10%;
Accordingly, the capacity of the foam mixer has been increased, which now ensures the simultaneous operation of 8 foam generators;
The design of the dispenser has been improved; thanks to the built-in gearbox, it is now possible to smoothly regulate the concentration and ensure economical consumption of any type of software;
The stuffing box assembly has been fundamentally redesigned; it does not require any maintenance and consumables, and in terms of wear resistance and reliability it has no analogues;
the pump is equipped with a full package of modern instrumentation and a built-in vacuum system of the “ABC” type (the advantages of this vacuum system are described in detail below).

What practical benefits can these benefits bring to your daily work?

Increased productivity and pressure allows you to save time on refueling the tank, which, under certain circumstances, helps in localizing large fires. It also becomes possible to use more powerful monitors and foam installations.

Efficiency is an indicator that is seemingly abstract and has no obvious practical importance. However, it is easy to calculate that increase in efficiency pump by 10% gives fuel savings of at least 2 liters per hour of operation. And over the entire service life of the pump, the savings on fuel and lubricants will be measured in tens of thousands of rubles. And these are no longer abstractions.

Speaking about economic effects, of course, it is worth mentioning the consumption of expensive foaming agent, which, with smooth and fine dosing in the NTsPN-40/100 pump, is carried out more rationally, as well as savings on repairs (replacements) and maintenance of the seal. However, not everything is measured in rubles. An important advantage of this pump, according to the developers, is is the so-called ergonomics - simplicity and ease of use. The driver-mechanic operating the pumping unit should not experience inconvenience and divert his attention to various additional operations (pressing the same oil seal, problems with water intake, jamming of the dispenser plug, etc.). Judging by consumer reviews, the creators of the pump have managed to make significant progress in this matter.

What technical difficulties may arise when installing this pump on an AC? And how expensive will the described modernization of the pumping unit cost?

No technical difficulties. All overall and connecting parameters of the NTsPN-40/100 pump completely coincide with the well-known PN-40UV. The pump can be replaced directly at the fire department.

When assessing the preference of a particular pump model from a price point of view, one should “bring them to a common denominator” in terms of equipment level and functionality. With this approach, we can say that the difference in price of pumps NTsPN-40/100 and PN-40UV is completely insignificant. And taking into account the direct economic advantages mentioned earlier, the use of NTsPN-40/100 is certainly more profitable.

One of the most important elements of the pumping unit is the vacuum water filling system.

A vacuum system is used to lift water from an open pond to a fire pump. Very high reliability requirements are placed on it. Its readiness for work must be checked daily. That is why this element of the pumping unit is subject to modernization as a matter of priority.

How can you replace an obsolete and unreliable ? Vacuum pump АВС-01Э – best solution for water filling systems of fire pumps.

This product is fundamentally different from all known analogues (including foreign ones) in that it operates independently of the AC propulsion motor and fire pump, i.e. offline. Hence its name: “ABC” – autonomous vacuum system.

Let's consider the advantages of the ABC-01E vacuum pump in comparison with the gas-jet vacuum apparatus (GVA), used in most ACs, when performing specific work operations.

Daily readiness checks (so-called “dry vacuum”) during guard changes. GVA - you need to start and warm up the engine (often you have to drive the car out of the box to do this), create the required level of vacuum in the cavity of the fire pump, operating the engine at high speeds. The procedure is so troublesome that sometimes it is neglected, in violation of established norms. ABC-01E – by pressing the button on the control panel, start the vacuum pump and after 5-7 seconds. the required vacuum level has been reached. The engine of the tank truck is not used.
. GVA - it is necessary to perform 11 operations in a clear sequence, manipulating the engine and pump controls. An inexperienced driver does not always succeed the first time. Good skills required. And at high suction heights, the GVA is often completely unable to create the required vacuum. ABC-01E – starts by pressing a button and turns off automatically when water is drawn. The vacuuming speed is such that water rises from the maximum suction height in 20-25 seconds, and at low heights even the presence of leaks in the suction line is not a hindrance.
Reliability and durability. GVA - works in an extremely aggressive environment, which determines its relatively short service life. ABC-01E has been mass-produced in large quantities since 2001. The results of controlled operation show very high level reliability. In addition, the product is equipped with electronic protection against overloads and all kinds of emergency situations.

What is the scope of application of the ABC-01E vacuum pump? Will it fit older model tank trucks? And what is required to install it?

This product is suitable for any pumping installations, including old tankers equipped with a PN-40UV pump. Installation of the product is very simple and can be done directly in parts (the product is supplied with detailed instructions). All special parts required for installation of АВС-0Э are included in the delivery set.

Does the use of ABC-01E provide economic benefits?

The initial price of ABC-01E is higher than the price of GVA. However, only savings on direct costs (fuels and lubricants) make it possible to obtain economic benefits from the use of ABC-01E within the next year or two after commissioning.

We must not forget about the human factor. It is quite obvious how much easier the work of technical personnel is when using the ABC-01E vacuum pump instead of the outdated GVA. In addition, one should not discount the indirect benefits associated with the higher reliability of ABC-01E. In addition to the inevitable additional costs for repairing the HVAC, it is quite possible that the failure of the HVAC at the most inopportune moment can lead to increased damage from a fire.

Developing the topic of modernizing a fire truck by replacing special units with more advanced models, one cannot fail to mention combined pumps.