Chiller 1, M20140609 Pressure leak test Circuits A/B
Following attendance, we found the Carrier Chiller 30XA 1 was short of refrigerant due to low back pressures and subsequent flashing of the indication sight glass this indicated we are not able to condense sufficient F-gas to complete the running cycle. We proposed to complete the following.
Schedule of Work, isolate the unit electrically and mechanically, recover refrigerant down to 1 psi into a dedicated recovery cylinder for weighing and re-use, pressure test with OFN (oxygen free nitrogen) to locate leak, repair leak by means of tightening of a fitting or brazing over of a pipe only, re-pressure test with OFN (oxygen free nitrogen) to prove system is leak tight, once proved release OFN to atmosphere and evacuate system to a minimum of 2 torr, re-charge with recovered refrigerant, carry out leak test as per F Gas regulation, test run and re-commission.
Works Carried Out:
- Circuit A – had no refrigerant in the system, we found a leak on prv (pressure relief valve) oil separator manifold.
- We refitted the manifold and re-tested.
- No further leaks were found.
- Evacuated overnight below 2 torr.
- Recharged partly with reclaimed refrigerant from chiller #3 and topped up with virgin. refrigerant.
- We ran tested circuit #1 and left all functional.
- Circuit B – we reclaimed 63 kgs of R134A from the circuit.
- Tested with ofn (oxygen free nitrogen).
- We located a small leak on the bottom of oil separator prv.
- Repaired with Loctite 577 and allowed to set overnight.
- No further leaks on the circuit.
- Evacuated below 2 torr.
- Recharged with reclaimed refrigerant, topping up 5kgs of virgin R134A.
- We ran tested the circuit B and left all operational.
- Both circuits fully functioning.