Leak Testing
Refrigerant leaks are best detected with a halide or electronic leak detector.
WARNING
Use of Pressure Regulator –
Valves – Gauges!
Always use pressure regulators, valves, and gauges to control drum and line pressures when pressure testing equipment. Failure to follow these instructions could result in an explosion causing death, serious injury, or equipment damage.
WARNING
Leak Testing!
Do not exceed 200 psig when leak testing system. Failure to follow these instructions could result in an explosion causing death or serious injury.
The importance of careful leak testing cannot be over emphasized. Undetected leaks invariably lead to repeated calls and eventually result in system contamination, restrictions and burned out compressors.
For a system that contains a refrigerant charge and is suspected of having a leak, stop the operation, check all tubing and fittings. Soap suds may also be used.
Note: The flame of the halide detector will glow green in the presence of R22 refrigerant.
If a leak is detected, do not attempt to apply more brazing material to the joint. Recover the charge, unbraze the joint, clean and rebraze.
For a system that has been newly repaired and does not contain a charge, connect a cylinder of refrigerant, through a gauge manifold, to the process tube of the compressor and liquid line strainer. Open the valve on the cylinder and manifold and allow the pressure to build up within the system. Check for and handle leaks as described above.
After the test has been completed, recover the test charge, evacuate the system, and recharge with clean refrigerant.
Maintenance
Brazing
WARNING
Hazard of Explosion!
Use only dry nitrogen with a pressure regulator for pressurizing unit. Do not use acetylene, oxygen or compressed air or mixtures containing them for pressure testing. Do not use mixtures of a hydrogen containing refrigerant and air above atmospheric pressure for pressure testing as they may become flammable and could result in an explosion. Refrigerant, when used as a trace gas should only be mixed with dry nitrogen for pressurizing units. Failure to follow these recommendations could result in death or serious injury or equipment or
CAUTION
High Temperatures!
Brazing requires high temperatures. Direct contact with hot surfaces may cause minor or moderate injury.
Satisfactory brazing results require cleanliness, experience and the use of proper material and equipment. Verify brazing connections are properly sized, free of rough edges, and clean.
Use of these generally accepted brazing materials:
•
Note: DO NOT USE FOR A COPPER TO STEEL CONNECTION.
Recommended heat is approximately 1400°F.
•SILVER SOLDER (Alloy of 30% silver, 38% copper, 32% zinc): use with fluoride base flux on copper to steel, brass to copper, steel to steel, or brass to steel. Recommended heat is approximately 1200°F.
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