P-250 MOD 1 PORTABLE PUMP

The P-250 Mod 1 is a gasoline-driven portable pump with an internal-combustion engine. It is used in fire fighting and in dewatering operations. When used for fire fighting, the P-250 Mod 1 draws water from the sea and pumps the water through suitable hoses and nozzles at a high pressure. When used for dewatering, it draws a large volume of water

from flooded compartments and discharges it into the sea. The P-250 Mod 1 can pump 250 gpm at 125 psig. It is hand primed up to a suction lift of 16 to 20 feet.

Before operating the P-250 Mod 1, make sure that all of the suction hose connections between the foot valve and the pump are tight. Be sure that proper-size gaskets are used at all of the suction connections. The strainer should be completely submerged in water. If the pump fails to draw water or if the discharge nozzle shows and uneven stream, look for a poor connection allowing air leakage into the suction side. The suction screen should rest in clear water-not in mud or debris, which might be drawn into the pump. The suction hose should be supported. The foot valve should be completely submerged when the pump is operating. Otherwise, severe damage could result. The pump must not be operated in a confined space unless the exhaust hose is connected to the pump. The exhaust hose carries the toxic engine exhaust gases to the atmosphere. The gas tank is a 6-gallon tank mounted on top of the pump frame. The tank consist of a single hose fitting, a fuel tank cap with an integral fuel gauge, a manually operated vent screw, and an explosion suppression arrangement (Explosafe).

Operate the P-250 Mod 1 pump as follows:

WARNING

Do NOT run the pump more than 20 seconds unless pressure shows on the

gauge. If pressure does not show on the pressure gauge, stop the pump and check all suction hose connections and gaskets. Then prime and restart. If the pump is operated for more than 15 to 20 seconds with the discharge valve closed, it may begin to cavitate and speed up due to

accumulation of air in the casing. Open the discharge valve momentarily to allow trapped air to escape.

1. Connect hoses to suction, discharge, and exhaust connections.

2. Close the pump discharge valve and make certain that the tee-handle screw on the rapid priming port is tight.

3. Check the fluid levels in the fuel tank and oil tank. Fill as necessary.

4. Attach the fuel tank to the top of the pump frame. Connect the fuel hose to the fuel tank and open the vent on the fuel tank cap.

5. Prime the fuel/oil injection pump by compressing the fuel and oil priming bulbs until they are firm.

6. Pull the engine carburetor primer two to three times to prime the carburetor.

7. Prime the pump by operating the manual priming pump until water is discharged out of the priming pump discharge.

8. Set the throttle lever and START/RUN switch to the START position.

9. Pull the manual starter handle and switch to the RUN position.

10. Adjust the engine throttle lever and open discharge valve slowly to obtain the desired pump discharge pressure.

11. While the engine is running, occasionally check the discharge to ensure it remains at the desired pressure.

12. To stop the unit, gradually return the throttle lever to the start position. Press the STOP button on the control panel, and keep it depressed until the engine comes to a complete stop.

If the engine is still warm from previous operation, the start-up procedure will be modified. Simply shift the START/RUN switch to the START position and pull the manual starter handle. Priming should not be necessary. If the engine does not start immediately, prime the carburetor and crank the engine until it starts. Upon completion of the pump operation, always prepare the pump for temporary storage in the following manner.

1. Flush the pump by operating the unit in freshwater for 5 minutes.

^2. Slow the engine speed and move the throttle lever to the START position.

3. Close the discharge valve.

4. Stop the engine by disconnecting the fuel hose. Allow the engine to run until fuel is burned out of the carburetors.

5. Remove the fuel tank.

6. Disconnect the suction, discharge, and exhaust hoses.

7. Allow the water to drain from the pump casing.

8. Grease the pump wear rings.

9. Replace the thread protectors on all connections; clean and dry the entire unit.

_10. Operate the pump once each month while it is in temporary stowage.

You can find additional information on the operation and maintenance of the P-250 pump

and P-250 MOD 1 in chapter 9930 of the Naval Ships' Technical Manual and in the manufacturer's technical manual furnished with the pump.

GAS CYLINDERS AND CYLINDER VALVES

You need to know the standard Navy system for marking gas cylinders, and to be able to identify the cylinder valves and cylinders of various gases. You should be familiar with the construction, design, and size of these cylinders. You should also know how to handle and stow gas cylinders in a safe and proper manner. This chapter will give you a few of the important facts about gas cylinders and cylinder valves. Additional information concerning compressed gases can be found in MIL-STD-101 B, Change 2, December 1970, Color Codes for Pipelines and for Compressed Gas Cylinders.