Refrigeration Maintenance
95
Discharge Pressure Regulator
Valve
This unit is equipped with a discharge pressure
regulator valve, which is located in the hot gas
line between the hot gas valve and the evaporator
coil distributor head. The discharge pressure
regulator valve maintains the compressor
discharge pressure at 340 to 400 psig (2344 to
2758 kPa) during heat and defrost operation.
These higher discharge pressures create higher
discharge temperatures, resulting in enhanced
heating capabilities.
The compressor discharge pressure is sensed at
the equalizer line on the valve. The valve dome is
pre-charged with nitrogen at a pressure of
325 psig (2241 kPa) at 70 F (21 C). The valve
opens and closes as the discharge pressure varies
to maintain the discharge pressure between 340
and 400 psig (2344 and 2758 kPa). The arrow on
the valve indicates the direction of flow.
The discharge pressure regulator valve is not
repairable and must be replaced as an assembly.
CAUTION: Before removing the valve,
cut the crimped charging line on the dome
to release the pressurized nitrogen. This
will allow the valve to open completely and
equalize the refrigerant pressures before
the refrigeration system is opened.
1.
Equalizer Line
2.
Charging Line
3.
Outlet
4.
Inlet
Figure 55: Discharge Pressure Regulator Valve
Assembly
ARA033
1
2
3
4
Summary of Contents for 919180
Page 4: ...4...
Page 10: ...Table of Contents 10...
Page 32: ...Unit Description 32 Unit Photographs Figure 3 Front View Figure 4 Back View AJA584 AJA585...
Page 33: ...Unit Description 33 Figure 5 Left Side View Figure 6 Right Side View AJA586 AJA58...
Page 35: ...Unit Description 35 Figure 8 North American Power Receptacle Box AJA58...
Page 38: ...Unit Description 38...
Page 58: ...Electrical Maintenance 58...
Page 66: ...Engine Maintenance 66 Figure 37 Fuel and Oil System Components...
Page 84: ...Engine Maintenance 84...
Page 96: ...Refrigeration Maintenance 96...
Page 118: ...Hilliard Clutch Maintenance 118...
Page 136: ...Cycle Diagrams 136...
Page 140: ...Wiring and Schematic Diagrams Index 140...
Page 141: ...141 Truck S Model SR 30 Schematic Diagram Page 1 of 2...
Page 142: ...142 Truck S Model SR 30 Schematic Diagram Page 2 of 2...
Page 143: ...143 Truck S Model 30 Units with P T Wiring Diagram Page 1 of 2...
Page 144: ...144 Truck S Model 30 Units with P T Wiring Diagram Page 2 of 2...
Page 145: ...145 Truck S Model 50 Schematic Diagram Page 1 of 2...
Page 146: ...146 Truck S Model 50 Schematic Diagram Page 2 of 2...
Page 147: ...147 Truck S Model 50 Units with P T Wiring Diagram Page 1 of 2...
Page 148: ...148 Truck S Model 50 Units with P T Wiring Diagram Page 2 of 2...