I have a JB Eliminator DV-3E vacuum pump. I have a BV mounted on the tree to relieve the vacuum prior to shutting it down. I have a T fitting with two vacuum rated hoses and use two Appion CRTs.

After vacuuming down a system I close the CRTs, open the BV on the pump for a few second, shut the pump off and put the exhaust pipe plug back in.

This was a MVAC or automotive system and was left for several days under a vacuum which held. I was going to break the vacuum with N2 and vacuum again. The T fitting was pointing straight up and when I removed the hose to use it for the N2, oil came running out of the fitting.

I emailed JB and they said that it shouldn’t happen and was I sure that it wasn’t system oil? The oil is BVA POE 100 day-glo or bright green. As long as it’s not too bright, it’s easy seen on white paper toweling. I replied to JB about the oil but they haven’t responded.

The JB is supposed to have a check valve in case of a power failure the pump oil won’t be pulled into the system. They said that it just had a ball which seals against the intake fitting which doesn’t sound good to me. I have seen these little rubber ball type check valves stick closed on can taps.

In the mean time I’ve added another BV on the pump before the T fitting.

Anybody else see this before?