View Poll Results: What provides the seal? The Schrader valve or its cap?
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The Schrader Valve.
The Service Port Cap.
Schrader Valve or Cap? What's the seal?
What ultimately provides the seal?
I'm talking about the common 1/4" service ports we connect our guages to. A member of another forum (Non HVAC&R related) called me out on what I believe to be true.
So what's y'alls thoughts?
When it comes to providing the actual sealing and containment of refrigerant within a given circuit at the schrader type service port, is it the valve core or the cap (that I keep finding laying on the floor of the compressor section )?
I say it's the cap.
While we're at it, if you believe it's the cap, what type do you prefer (and why)? Metal for its new metal-to-metal seal with each snugging or the metal/plastic with an O-ring?
I'm a new member of these forums and just cut the cheese in the back of the room. Opps.
Last edited by BC847; 07-10-2008 at 12:36 AM.
The valve core only seals long enough so you can remove you gauges and put the cap on which actually seals it. Not saying it is going to leak, but it won't leak for sure if the cap is tightened down on it.
Yup (you're preaching to the choir).
Originally Posted by Joe Cool
If you didn't do it right the first time it probably makes sense that your here asking the right way to do it now
Both. Now, guess which one is the primary and which one is the backup.
It is only rubber
The cap is what protects the loss during cool days.
Do it right the first time.
Generally the valve seals pretty well. but they can get crap under the seat. I've had ice build up in the valve and push the core down. I've seen the valves on discharge lines seats fail due to over heating. On the same valve I've seen the brass caps rubber seal fail for the same reason (heat).
When we get refits in the local supermarkets the commissioning bloke goes round and replaces all the quickseal brass caps with flare nuts and copper bonnets. He says it's cheaper than replacing a charge in a rack
Mistakes are a part of being human. Appreciate your mistakes for what they are: precious life lessons that can only be learned the hard way. Unless it's a fatal mistake, which, at least, others can learn from. Al Franken, "Oh, the Things I Know", 2002
True Heavy Metal Geek
neither one stops the leak. a schrader port is a hole in an otherwise sealed system. this hole leaks it must be stopped with a schrader valve and a cap with O-ring.
The valve core.
If the cap is put on to tight it warps the body where the valve goes.
If the valve gives out the cap is still there with the oring to minimize loses.
If valves blow they let it all out. I believe the thinking behind the cap is sto slow the leak down till someone identifies they have a problem before ref. is completely out.
Lots of system you walk up to have no caps on them and I don;t find many of just the valves leaks.
I have found valves that were shot or leaked slightly and with the cap on and you pull it off you hear "tiss" for a sec.
to minimize loss there is a primary....the valve...and the secondary back up the valve....to keep out debris.
If they have plastic caps they are really only to keep debris out while at least the brass ones can serve as a temp means to keep excess ref. from escaping in case of valve core failure.
All in all i check for a leak after I tighten the cap,cause after that who gives a rats ass if the valve core leaks or not.
There are three signs of old age.
The first is your loss of memory,
the other two I forget.