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 TM 55-1905-220-14-8
4-29.
AIR CONDITIONING SYSTEM - MAINTENANCE INSTRUCTIONS (Continued).
k. Water Regulating Valves.
(1) The water regulating valves are modulated type valves which automatically control the sea water
flow through the condenser to maintain a relatively constant condensing pressure and temperature. Water
regulating valves are actuated by refrigerant head pressure in condenser.
(2) Operation.
(a) Refrigerant head pressure from condenser is applied to bellows assembly. When refrigerant
head pressure increases, the bellows plate is compressed forcing the bellows push rod upward, moving the
valve seat in the opening direction and allowing increased water flow through condenser. As the valve unseats,
pressure is exerted upward through valve disc, valve disc holder, guide post and valve center assembly screw
to compress range spring.
(b) Increased water flow through condenser reduces head pressure. When head pressure
decreases, the range spring expands moving the valve seat in the closing direction and reducing water flow.
(3) Adjustment.
The opening point of the valve can be adjusted by turning the adjusting stem. To raise valve opening
point, turn adjusting stem counterclockwise. To lower valve opening point, turn adjusting stem clockwise.
Closing point of valve is about 3 to 7 psi (20.7 to 48.3 kPa) below opening point and is non-adjustable. Adjust
valve to maintain a refrigerant head pressure of 90 to 125 psig (620.5 to 861.9 kPa).
NOTE
If compressor operates in high ambient temperatures, gas
pressure may at times remain high enough to cause valve to
partly open when compressor is idle. In such a case, raise
opening point of valve just enough to cause valve to close
during compressor stand-by periods.
4-887
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