TM 10-4610-310-14
0009 00
Engine Air shutoff Assembly.
The diesel engine is equipped with an air shutoff valve located behind the intake filter housing. The air shutoff
valve must be in open position before the diesel engine can be started. Under normal circumstances, this takes
place automatically. An air cylinder actuates the valve. During normal operations, the solenoid valve allows the
pressurized air from the air tank to travel to the cylinder, which then opens the valve and holds it open. When
the level in the filtrate tank on the UF module falls below a preset limit; or the operating pressure in the RO
module exceeds 1250 psi; or the electrical supply is lost, the solenoid vents off the air supply, which closes the
air shutoff valve and causes the engine to shut down. It takes at least 20 psi (1.38 bar) for the air cylinder to be
operational.
In case of emergency or failure of the engine shutoff assembly, a manual override mechanism is
provided to keep the shutoff valve open and allow the operation of the LWP. Automatic shutoff is
incapacitated during manual override and the high-pressure pump is not protected from lack of
incoming water.
CAUTION
Do not use the manual override other than emergency situations. Damage to equipment
may result.
If the manual override is to be employed,
1. Pull the manual override handle out completely.
2. Rotate the handle 90 degrees in either direction (to vertical) and slide it into the deeper slot. See Figure 23.
3. Rotate the T handle on the air shutoff valve until it locks open.
4. Start the engine as usual.
5. To shut down the diesel engine, pull the manual override handle out completely and the shutoff
valve will snap close.
T HANDLE
OVERRIDE POSITION
NORMAL RUN POSITION
SOLENOID
VALVE
AIR CYLINDER
Figure 22. Operation of the Manual Override.
