| Tweet |
Custom Search
|
|
|
||
 TM 55-1905-219-14-8
4-7.9.
PRESSURE REGULATOR AND OPERATING CYLINDER - MAINTENANCE
INSTRUCTIONS.
a.
The pressure regulator is mounted on the pump end of the exhaust receiver, and its adjusting
screw is accessible through a hole in the hood. By means of this adjusting screw, the pressure of the water
delivered by the fire pump may be adjusted within a range from 80 pounds per square inch to 120 pounds per
square inch, (551.6 -827.4 kPa), depending on the volume of water being delivered by the pump, which is
determined by the size and number of nozzles used.
b.
Inside the regulator is a bellows, which is connected by tubing to a similar bellows on the pressure
side of the pump. The bellows and tube assembly is filled with a non-freezing liquid. The bellows in the
regulator operates a small metering valve. There is a water line from the pump to this valve, and a pressure
line from the regulator to the operating cylinder. The metering valve regulates the water pressure delivered to
the operating cylinder.
c.
The operating cylinder is in turn connected by mechanical linkage to both the throttle valve
(carburetor) and the magneto. When the engine is not running, there is no water pressure transmitted to the
operating cylinder.
4-229
|
||
|
||
