Section XIV. MAINTENANCE OF PUMP - TM-5-4320-272-120073

(5) Inspect the tool box for cracks, dents,

damage; replace damaged reflectors.

severe rust, and other damage. You can remove

c. Reassembly. Reassemble and install the fire

minor rust with fine sandpaper. Refinish all areas

extinguisher, tool box, and reflectors as shown in

requiring it. Replace a damaged tool box.

figure 4-15.

( 6 ) Inspect the reflectors for cracks and

Section XIV. MAINTENANCE OF PUMP

4-40. Description

fluid through the pump by closing automatically at

shutdown. This is the normal mode of operation.

a. Suction Piping and Strainer. The suction

However, if you want the check valve to remain

system of the pump has dual, four-inch gate valves

open at shutdown so that the discharge lines drain

connected to a suction manifold. A strainer is

back to the fuel source (provided that the discharge

connected between the suction manifold and the

lines are higher than the pump inlet), you can

pump to remove solid materials from the fluid

adjust the valve to provide this type of operation.

being pumped. The suction system is provided with

e. Air Eliminator. The air eliminator assembly

female quick-disconnect fittings to facilitate your

is provided in the discharge line to expel the air

connection of the intake hoses.

during the priming cycle. It consists primarily of a

b. Discharge Piping. The discharge piping

float-operated valve that remains open until the

system of the centrifugal pump has two discharge

liquid in the air eliminator body reaches a level high

valves connected to a discharge manifold. Between

enough to buoy up the float and close the valve.

the discharge manifold and the pump are a lever-

Prior to this time the air in the housing is allowed to

operated check valve and an air eliminator. The

escape through the valve. The closing of the valve

check valve prevents reverse flow of fluid through

prevents the liquid from discharging through the

the pump. If desired, you can override the normal

valve.

check valve operation. The air eliminator expels air

from the pump during priming cycle.

4-41. Suction Piping and Strainer

c. Gate Value. Suction and discharge gate

a. Removal and Disassembly.

valves are identical. When you rotate the valve

(1) Make sure the piping is drained of all fluid

handwheel to open the valve, the valve disc

and intake hoses are disconnected before you begin

assembly is raised from the valve seat to allow fluid

to disassemble the piping.

flow. When you rotate the handwheel to close the

(2) Disconnect the pump suction gage hose

valve, the stem first lowers the disc assembly into

from the strainer housing.

alinement with the valve seat and then expands the

(3) Service the suction strainer (para 3-12).

parts of the disc assembly outward to seal the fluid

(4) Disassemble the suction piping as shown

flow through the valve.

in figure 4-16.

d. Check Value. The check valve is mounted in

the discharge line to prevent the reverse flow of

4-33