Table of Contents
Advertisement
5 2
Section E - Refrigeration System
TESTING FOR REFRIGERANT LEAKS
If the system is diagnosed as short of refrigerant and the system has not been
recently opened, there is probably a leak in the system. Adding refrigerant without
first locating and repairing the leak or replacing the component will not permanently
correct the difficulty. The leak must be found. Sufficient refrigerant may have
escaped to make it impossible to leak test effectively. In such cases, add a ¼" line
piercing valve to the compressor process tube. Add sufficient refrigerant vapor to
increase the pressure to 40 to 50 lb. per sq. in. Check the low side for leaks. Run
the compressor 2 or 3 minutes and check the high side for leaks. Recover
refrigerant using an EPA approved recovery system.
N OTE
The line piercing valve (clamp-on type) should be used for test purposes only. It must
be removed from system after it has served its purpose.
CHECKING FOR INTERNAL (HOT TUBE) LEAKS
Before checking for internal leaks, check all accessible system components and
joints for leaks.
If an internal hot tube leak is suspected, it must be confirmed. Use the following
procedure:
1.
Recover refrigerant by using EPA approved recovery system.
2.
After system refrigerant is completely recovered, disconnect drier from hot
tube. Pinch off and solder end of hot tube closed.
3.
Cut line from condenser to hot tube and solder a ¼"charging hose fitting to
open end of hot tube or put compression fitting on tube.
4.
Connect pressure gauge and access valve to hot tube and pressurize to 250
psig using dry nitrogen or carbon dioxide.
WARNING
NEVER PRESSURIZE WITH OXYGEN. NEVER OPEN A HIGH PRESSURE TANK UNLESS IT
IS EQUIPPED WITH A PRESSURE REGULATOR. NEVER PUT HIGH PRESSURE ON DOME
OF COMPRESSOR – IT COULD EXPLODE. MAKE SURE GAUGE, HOSES, AND ALL
FITTINGS ARE IN GOOD CONDITION AND DO NOT LEAK.
5.
Leave pressure on hot tube for 24 hours. Any drop in pressure is indication of
leak.
Hide quick links:
Advertisement
Table of Contents
