Installation and Maintenance Manual

Installation - Mechanical
RLC-SVX09H-EN 57
Refrigerant Relief Valve Venting
High Pressure Side Relief Valve Venting
(RTWD-Condenser, RTUD-Oil Separator)
All RTWD units utilize a refrigerant-pressure relief valve for
each circuit which must be vented to the outdoor
atmosphere.The valves are located at the top of the
condenser. Relief valve connections are 5/8” MFL. See
Figure 33. Refer to local codes for relief valve vent line
sizing requirements.
All RTUD units utilize a refrigerant-pressure relief valve for
each circuit which must be vented to the outdoor
atmosphere.The valves are located at the top of the oil
separator. Relief valve connections are 3/8” MFL. Refer to
local codes for relief valve vent line sizing requirements.
High side relief valve discharge setpoints are 300 psig for
RTWD, and 350 psig for RTUD units. Once the relief valve
has opened, it will reclose when pressure is reduced to a
safe level.
Note: Vent line length must not exceed code
recommendations. If the line length will exceed
code recommendations for the outlet size of the
valve, install a vent line of the next larger pipe size.
Pipe each relief valve on the unit into a common vent line.
Provide access valve located at the low point of the vent
piping, to enable draining of any condensate that may
accumulate in the piping.
If multiple chillers are installed, each unit may have a
separate venting for its relief valves. If multiple relief
valves are vented together, see ASHRAE 15, and/or local
codes for sizing requirements.
Note: RTWD units can be ordered with “Dual Relief
Valve” options. Model number digit 16 is a “2”.
Units with this option will have two valves on each
circuit for a total of four on the condenser. Only two
valves would release at the same time - never all
four.
Low Pressure Side Relief Valve Venting
(Evaporator)
Low-side refrigerant-pressure relief valves are located on
the top of the evaporator shell, one per circuit. Each must
be vented to the outdoor atmosphere. Relief valve
connections are 3/4” NPTFI.
Note: RTWD units can be ordered with “Dual Relief
Valve” option. Model number digit 16 is a “2”. Units
with this option will have two valves on each circuit
for a total of four on the evaporator. Only two
valves would release at the same time - never all
four.
See Figure 33, p. 57 and Table 37, p. 58. Refer to local
codes for relief valve vent line sizing requirements.
WARNING
Refrigerant under High Pressure!
System contains oil and refrigerant under high
pressure. Recover refrigerant to relieve pressure before
opening the system. See unit nameplate for refrigerant
type. Do not use non-approved refrigerants, refrigerant
substitutes, or refrigerant additives. Failure to recover
refrigerant to relieve pressure or the use of non-
approved refrigerants, refrigerant substitutes, or
refrigerant additives could result in an explosion which
could result in death or serious injury or equipment
damage.
NOTICE:
Equipment Damage!
To prevent shell damage, install pressure relief
valves in both the evaporator and condenser
water systems.
NOTICE:
Equipment Damage!
To prevent capacity reduction and relief valve
damage, do not exceed vent piping code
specifications.
Figure 33. High pressure side relief valves
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#ONDENSER
2ELIEF6ALVES
Condenser Relief Valves (RTWD only)
Oil Separator Relief Valves (RTUD only)