Hey Guys
i'm working on a large walk-in freezer condensing unit with a copeland 9rb model semi hermetic compressor.
i found a leak where a service port T was cross threaded onto the receiver discharge service valve.
1. I was told the only way to repair would be to recover the full charge then repair the leak. is this true? or can i pump the system down by closing suction valve then at low pressure cut out close the discharge valve?
2. the oil in the sight glass looks frothy and low (1/8" above bottom of sight glass while running). i'll get the net oil pressure later today to confirm. i was thinking of changing it while i had the system down repairing the leak. what service ports on the compressor do i evacuate after completing an oil change and/or replacing gaskets?
Most likely not. On those kinds of valve the center port is always open to the system and typically won’t have a shrader core. You just need to keep a good cap on it really tight.
Hey Guys
i'm working on a large walk-in freezer condensing unit with a copeland 9rb model semi hermetic compressor.
i found a leak where a service port T was cross threaded onto the receiver discharge service valve.
1. I was told the only way to repair would be to recover the full charge then repair the leak. is this true? or can i pump the system down by closing suction valve then at low pressure cut out close the discharge valve?
2. the oil in the sight glass looks frothy and low (1/8" above bottom of sight glass while running). i'll get the net oil pressure later today to confirm. i was thinking of changing it while i had the system down repairing the leak. what service ports on the compressor do i evacuate after completing an oil change and/or replacing gaskets?
The method you describe to pump it down won’t do anything to pump out the receiver.
To replace that valve you’re going to have to recover the charge.
Most likely not. On those kinds of valve the center port is always open to the system and typically won’t have a shrader core. You just need to keep a good cap on it really tight.
You're probably right. I know a few times on compressor mounted suction service valves, theres been a schrader in one. But maybe thats a different type?
They typically don't have a Schrader because there's usually a permit gauge connected to it..It's actually the best way to mount such gauge because the valve can be backseated and not have to be mid seated. Mid seated relies on the packing to hold back the charge.
Most likely not. On those kinds of valve the center port is always open to the system and typically won’t have a shrader core. You just need to keep a good cap on it really tight.
And here I was told a while back that the only way a service port would not leak is if it has a non leaking core. The cap is just a dust cap I was told and you can't trust it not to leak without a good schrader core.
And here I was told a while back that the only way a service port would not leak is if it has a non leaking core. The cap is just a dust cap I was told and you can't trust it not to leak without a good schrader core.
I use those brass hex caps with the built-in copper washer for that.
I've never seen a Shraeder valve on any service valve port...that I can recall.
Generally, as a UL requirement, the condensing unit OEM will usually provide access ports for safety controls, like the HPC, on the discharge line or receiver without a Shrader as well...as long as there is no discharge service valve the compressor. Compressors with discharge service valves will have the HPC connected to the center port. Ports intended for operational controls will "usually" have Shraeders.
In the past, "real" refrigeration condensing units always had traditional style service valve for everything. I suspect it won't be much longer before they disappear altogether.
In the past, "real" refrigeration condensing units always had traditional style service valve for everything. I suspect it won't be much longer before they disappear altogether.
Worked on a hoshizaki self contained reach in cooler the other day. Not only did it have service ports, they were real service valves! It was less than 2 years old.
In the past, "real" refrigeration condensing units always had traditional style service valve for everything. I suspect it won't be much longer before they disappear altogether.
Yeah I miss being able to tighten the stem packing nut.
I miss the solid brass valves that were not only serviceable, but they didn't rust and lasted forever.
Tell me about it.
We installed a new Copeland condensing unit about 2 years ago and the suction service valve already rusted to the point of leaking at the pipe connection.
And here I was told a while back that the only way a service port would not leak is if it has a non leaking core. The cap is just a dust cap I was told and you can't trust it not to leak without a good schrader core.
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Originally Posted by pecmsg
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