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i-5
Glossary
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Table of Contents-
Indexlow side
— the low pressure side of a system, from
the expansion valve orifice to the compressor inlet
low side service valve
— a valve on the compres-
sor used to service the low pressure side of the
system and permit it to be checked
lubricant
— refrigeration oil specially formulated
to be free of all contaminants and moisture. Note:
different for R-12 and R-134a
magnetic clutch
— an electrically operated de-
vice used to cycle the compressor on and off
manifold
— the part of the manifold gauge device
designed to control refrigerant flow
manifold gauge hoses
— hoses connected to the
manifold gauge set used to test, evacuate, recover
and charge the air conditioning system
manifold gauge set
— a system measuring device
containing two (sometimes three) gauges and three
or more service connections
melting point
— the temperature at which a solid
turns into a liquid
mercury
— used to indicate the amount of vacuum
(a perfect vacuum is 29.92 inches of mercury at sea
level)
molecular sieve
— a drying agent used in the
receiver-drier to absorb moisture and filter con-
taminants out of the refrigerant
natures laws
— the principals of conduct in natu-
ral process or function in nature
PAG
— a polyalkylene glycol lubricant used in
many R-134a systems
parallel flow
— a coil design where refrigerant
flows through both upper and lower tubing at the
same time
phosgene
— a poison gas produced when R-12
comes in contact with an open flame
POA valve
— a suction throttling valve used in
some systems
pressure drop
— pressure lost while passing
through a component, the difference between pres-
sure in and pressure out
pressure range
— a measured spread between a
high and low pressure
pressure switch
— a pressure sensitive electrical
switch mounted at the receiver-drier, on some accu-
mulators or in the suction line to activate or inter-
rupt electrical current cycling the compressor
clutch
propane
— a flammable gas used in the Halide
leak detector
psi
— abbreviation for “pounds per square inch”
psig
— abbreviation for “pounds per square inch
gauge”
purge
— to remove the refrigerant from an AC
system and hoses by opening the system or using
pressure to eliminate the contents
R-12
— the common name of the refrigerant used
in vehicle air conditioner systems to move heat
energy
R-134a
— a new refrigerant which does not harm
the atmosphere
radial compressor
— a compressor that has pis-
tons in a radial design
radiation
— heat waves (heat energy) passing
through the air
radiator shutter
— a metal vane assembly on
some truck radiators where the vanes can be
opened or closed to allow or exclude ram air flow to
the radiator, radiator mounted condenser and en-
gine
ram air
— air through which a vehicle passes,
increasing in force as the speed of the vehicle in-
creases
receiver-drier
— a container which receives,
stores, and removes moisture from refrigerant
reciprocating compressor
— a compressor hav-
ing pistons that move back and forth in cylinders
reclaim
– the process of restoring refrigerant to
new product specifications
recovery
– the process of removing refrigerant
from an AC system