Water Regulating Valve.

TM 55-1905-223-24-17

(6)

(a)

The water regulating valve on self-contained units (A/C 1 and 3) is automatic and non-

adjustable. These valves are set for 95 F outlet water temperature. The regulating valve

on A/C 2 (accommodations) is adjustable and is designed for 210 psig discharge (head)

pressure.

(7)

Moisture Indicator (A/C-2; Accommodations). Moisture indicator is placed in refrigerant line to

show the wet or dry condition of the refrigerant. The indicator has a viewing glass that shows a

positive change from green (dry condition) to yellow (wet condition). When the indicator shows

yellow, the system must be purged, evacuated, and recharged with R-22.

(8)

Refrigeration Ball Check Valves (A/C-2; Accommodations). Ball check valves are placed in

refrigerant lines to control the direction of flow through the lines. Two types of valves are used in

the system.

(a)

Valve with Visual Exposed OPEN/CLOSE Indicator. This type of valve can be visually

checked to determine if it is opened or closed. This type of valve is manually opened or

closed by turning the indicator stem 1/4 turn.

(b)

Valve with Unexposed OPEN/CLOSED Indicator. This type of valve has a brass seal cap

that must be removed to expose the OPEN/CLOSED indicator. This type valve is also

manually opened or closed by turning the indicator stem 1/4 turn.

(9)

Refrigerant Receiver (A/C-2; Accommodations). The receiver is a tank, or cylinder, located in

the liquid refrigerant (high side) line that serves three purposes on large air conditioning units.

The smaller self-contained units do not have a receiver.

(a)

Acts as a refrigerant surge suppressor from the compressor pump and condenser where

the pump and condenser are overloaded for short periods of time.

(b)

Stores a sufficient amount of liquid refrigerant to keep the expansion valve adequately

supplied when small leaks may occur over long periods of time.

(c)

The receiver is large enough to hold most of the refrigerant when pumping down the

system.

(10) Hot Gas Valve (A/C-2; Accommodations). During low-load periods, the hot gas valve opens,

allowing hot gas to flow to the cooling coil. This action induces the air conditioner to run longer,

avoiding shut run cycles. When demand cycles the air conditioner off, a solenoid on the hot gas

valve closes. This action prevents the hot gas valve from keeping the system running longer

than necessary.

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