gForce Ultra IOM
28
Refrigerant Piping Protection
The refrigerant in the system(s) is under high-pressure and this pressure can rapidly increase if the
refrigerant is unintentionally confined (or trapped) between isolation devices such as service valves,
liquid line solenoid valves, expansion valves, etc. If the ambient temperature surrounding the piping
system increases, this may cause the contained refrigerant pressure to increase to an unacceptable
level.
WARNING: This increased pressure can cause piping ruptures,
discharge of refrigerant, pollution, equipment damage, injury or death.
Use extreme caution when:
1. Installing the piping lines and make certain that these isolation devices
are open to prevent unintended containment (trapping) of refrigerant.
2. When charging a refrigerant system, do not exceed the Design
Pressure indicated on the unit nameplate.
3. Ensure that pressure has a path to expand when cutting or making
connections, disconnections and piping repairs.
The installing contractor must review the piping system and guard against these possible areas where
the refrigerant could be confined. If the areas cannot be vented and allow the refrigerant to expanded
freely or eliminate pressure increases, the installing contractor must field supply pressure relief devices.
Additionally, the installing contractor must consult local building and piping codes regarding installing
pressure-safety devices in the required areas of the piping system(s) that could be unintentionally
isolated during field installation, maintenance or repairs of the refrigerant systems.
After a “Direct Type” Relief Device has discharged once, it should be replaced. The “Direct Type” Relief
Device is designed to reclose automatically at a predetermined pressure, but reliability of the device to
reseal tightly and to operate at the designed pressure cannot be guaranteed after discharging. Be safe
and replace the device after such an occurrence.
NOTE: Receivers are often installed on condensers and condensing units.
The receiver includes a safety pressure-device to protect the receiver, but
the receiver also includes service valves which, if closed, will isolate this
pressure-safety device and only protect the receiver. If these valves are
closed, the rest of the piping system would not be protected from
unintended refrigerant pressure in- creases. Again, the installing contractor
must review the piping system and guard against trapping the refrigerant
by installing field supplied pressure-safety devices.
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