Pressure Test Pass. Vac test fail.

[Dillan]

Hi all,

I am new to the refrigeration sector. Recently I received a call out to an industrial switch room cooling system. The system was tripping on high head pressure. This system uses a fresh water condenser with a 12oC inlet temp. It also uses a danfoss head pressure control valve. However upon inspection the liquid sightglass doesn’t have a moisture indicator. The liquid looked “milky” in colour. I proceeded to recover refrigerant as I suspected a burst condenser. When pressure tested the condenser held 21bar overnight. Released a pressure, before I put it on a vac I put gloves over the water inlet and outlet connections of the condenser. When system was in a deep vac I noticed the gloves had been sucked inside the condenser. At this point the vac was also rising in pressure. Has anyone ever had similar issues. Seems strange that it would pass a pressure test and fail on vacuum. I also checked and manually opened the head pressure control valve and rodded the condenser to eliminate that.

[seanf]

Yer had similar leaks only showing up on vac, also leaks only showing up when parts get warmed up or cool down during running.

[al]

Fair play on thinking of putting the gloves on, nice touch. Have had similar, usually threaded joints. Was the refrigerant or oil contaminated?