Help. Vacuum pump oil sucked into system.

[rpauls]

Hi all,
I was working on a system last week and got vacuum pump oil sucked back into the system during evacuation. After pressure testing I had vacuumed down to 500 microns and blocked off the system by ball valves at the charging ports and turned off the pump. I should have closed the pump valve, but did not. Apparently the automatic check valve is not working, and oil from the pump was sucked out into the hose set and manifold (about 4 ounces). I did not know this at the time. After 20 mins or so the vacuum in the system rose to about 1000 microns and I turned the pump back on and opened the two ball valves. My first clue something was wrong was that the vacuum did not go down, then I saw that the oil level in the pump was low. When I took the hoses off they were filled with oil. I have no way of knowing if or how much oil may have entered the system.

This was a new startup. Charge has not yet been released from compressor. I want to clean this up right. Do I need to flush the lines or can I just blow it out with nitrogen? I did install an access port at the evaporator so I could flush or blow out from there to the service valves.

Many thanks for your advice,

Rich

[raidersfan7]

YES U NEED TO FLUSH SYSTEM.......TREAT IT LIKE A BURNOUT....

[Twilly]

Twilli says rut-roh

[bustawrench1]

Flush lineset and evap and blow out with nitro, change the compressor oil a couple of times, once at 24 hours and agian within the first week. Should be ok after that............we're not talking an entire quart of oil here, right?

[Texas-Tech]

For that small amount of oil I'm not sure if it will be a problem or not. Sounds pretty strange to me, never had that happen before. Did you look under the pump for oil?

[rpauls]

For that small amount of oil I'm not sure if it will be a problem or not. Sounds pretty strange to me, never had that happen before. Did you look under the pump for oil?

Yeah, it sounds strange to me too. There is supposed to be a valve in the pump (Robinair 15400) to prevent exactly this, but it must not be working.

I just checked the oil level now. There is about 3 oz missing, and I'm sure the hose set and manifold must hold this much alone (it is a 3/8 evac hose). Maybe only about 1/2 oz may have gotten into the lineset, maybe none, problem is I have no way to know for sure.

As I said, this is a new system and the charge has not yet been release from the compressor. Is the vacuum pump oil so very different than the oil in the compressor already? (R22 system)

[rpauls]

Flush lineset and evap and blow out with nitro, change the compressor oil a couple of times, once at 24 hours and agian within the first week. Should be ok after that............we're not talking an entire quart of oil here, right?

Since I posted earlier today I've been doing some research on this. Apparently the only potential issue is oil breakdown if the oils are incompatible. Seems like it might not be a problem since it is an R22 system, which is either mineral oil or AB based and the vacuum pump oil is also mineral oil.

Given that it is R22 do you guys still think an ounce of vacuum pump oil merits a complete system flush?

[t527ed]

since you have not broken the system open yet i would blow what i could out of it and pull another vacuum.

since it is a r-22 system i would not lose a minutes sleep over it.

[phxurs]

I Agree blow out and pull Vac - cant be much if any?

flush / ad Dryer if you fell like your not sure....and it will keep you up at night

[beenthere]

Just blow it out.

[mustardman]

I agree blow it out and then get your vacuum pump fixed.

[rpauls]

Thanks for all the replies. I've decided to blow it out with nitro today and re-evac. During the blow out I'll be able to see how much oil/mist comes out anyway. If there's any problem I'll post a followup.

[vmc1161]

Many years ago there was a maintenance guy who put in vacuum pump oil instead of 3gs and the morgue unit ran fine. That is until he added even more oil...this time the right oil but to much by over a gallon. That's when they called us, seems the compressor was making noise... We cleaned it all out, we took everything apart. The unit ran fine after that, he was filling by the oil sight glass...problem was it was already full...and then some. This happened over about a six month period. We figured out the vacuum oil by the fact that he left all his trash behind and we asked him why the empty containers...oh I added oil...hey that's not refrigeration oil... He pleaded with us to not tell on him…we did not…

.

[Paul savage]

Hi all,
I was working on a system last week and got vacuum pump oil sucked back into the system during evacuation. After pressure testing I had vacuumed down to 500 microns and blocked off the system by ball valves at the charging ports and turned off the pump. I should have closed the pump valve, but did not. Apparently the automatic check valve is not working, and oil from the pump was sucked out into the hose set and manifold (about 4 ounces). I did not know this at the time. After 20 mins or so the vacuum in the system rose to about 1000 microns and I turned the pump back on and opened the two ball valves. My first clue something was wrong was that the vacuum did not go down, then I saw that the oil level in the pump was low. When I took the hoses off they were filled with oil. I have no way of knowing if or how much oil may have entered the system.

This was a new startup. Charge has not yet been released from compressor. I want to clean this up right. Do I need to flush the lines or can I just blow it out with nitrogen? I did install an access port at the evaporator so I could flush or blow out from there to the service valves.

Many thanks for your advice,

Rich

So I know this is a very old thread but I wanted to add my experience here so others would have this information. It was the first search result when I was panicking so hopefully others will end up here too...
So I was pulling a vaccum on a 7 ton lennox RTU after a condensor coil replacement. We use a solenoid valve inline, plugged in with the pump to prevent these issues if there's a power failure or some a hole unplugs our pump. Anyways fresh oil in pump and left it overnight.... come back the next day.... pumps not running and its dry on oil.....not much in my vac hoses either...oh crap and that's how I ended up here the first time. So after confirming the entire pump of oil was inside this 410 system we start to weigh our options.....we decide after some research that we will pull another vaccum and see how it runs.....so that was about 8 months ago.. system ran fine with normal pressures for conditions on startup and we haven't been back other than for preventative maint. So no we didn't tell the customer and yes we would have eaten it if it went badly. Long story short... didn't seem to have any issiues it's a 410 system with Poe And it was nu calgon vac pump oil. So I dont know if anyone has had a real bad experience as a result of this kind of mishap but mine went well I will update here if I ever hear anything further on this system. But I figured 8 months was a pretty good trial period. Further details..... there was no power failure as the solenoid never closed.... I think the pump just died.... and it was having trouble pulling below 100 microns with the gauge direct to the pump that week so I think it was getting weak and worn out. (Newer pumps always pull at least 50 microns directly at the pump in my experience) if anyone has any questions feel free to contact me. And dont sweat it too bad lol I know I was pretty puckered it happened. Cheers

Paul