49
INSTALL VENT PIPING TO RELIEF VALVES —
The 23XRV chiller is factory equipped with relief valves on
the cooler and condenser shells. Refer to Fig. 59 and Table 21
for size and location of relief devices. Vent relief devices to the
outdoors in accordance with ANSI/ASHRAE 15 (latest
edition) Safety Code for Mechanical Refrigeration and all
other applicable codes.
1. Dual pressure relief valves are mounted on the three-way
valves in some locations to allow testing and repair with-
out transferring the refrigerant charge. Three-way valve
shafts should be turned either fully clockwise or fully
counterclockwise so only one relief valve is exposed to
refrigerant pressure at a time.
The flow area of discharge piping routed from more than
one relief valve, or more than one heat exchanger, must
be greater than the sum of the outlet areas of all relief
valves that are expected to discharge simultaneously. All
relief valves within a machinery room that are exposed to
refrigerant may discharge simultaneously in the event of a
fire. Discharge piping should lead to the point of final
release as directly as possible with consideration of pres-
sure drop in all sections downstream of the relief valves.
2. Provide a pipe plug near outlet side of each relief device
for leak testing. Provide pipe fittings that allow vent
piping to be disconnected periodically for inspection of
valve mechanism.
3. Piping to relief devices must not apply stress to the
device. Adequately support piping. A length of flexible
tubing or piping near the relief device is essential on
spring-isolated machines.
4. Cover the outdoor vent with a rain cap and place a
condensation drain at the low point in the vent piping to
prevent water build-up on the atmospheric side of the
relief device.
COOLER
CONTROL CENTER
COOLER REFRIGERANT
PUMPOUT VALVE
COOLER INLET
ISOLATION VALVE
COOLER CHARGING
VALVE
CONDENSER
CHARGING
VALVE
DISCHARGE ISOLATION
VALVE (OPTIONAL)
OIL
SEPARATOR
PUMPOUT
CONDENSER
WATER SUPPLY
AND RETURN
PUMPOUT
CONDENSER
2
3
4
5
PRESSURE
RELIEF SAFETY
VALVE
PUMPOUT
COMPRESSOR
SERVICE VALVE
1a
SERVICE VALVE ON
PUMPOUT UNIT
=
SERVICE VALVE ON
CHILLER
=
7
1a
1b
11
Fig. 57 — Optional Pumpout System Piping Schematic without Storage Tank — Configured to Store
Refrigerant in Cooler or Condenser (Unit with R Compressor Shown)
a23-1545
COMPRESSOR
OIL
SEPARATOR
CONDENSER
LEAVING
WATER
ENTERING
WATER
VALVE
5
VALVE
4
VALVE
2
CONTROL
PA NE L
FRAME
ASSEMBLY
OIL
HEATER
VALVE
3
OIL FILL
FITTING
Fig. 58 — Pumpout Unit
a23-1546
DANGER
Refrigerant discharged into confined spaces can displace
oxygen and cause asphyxiation.
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