Check Valve, How Tight?

Old 07-24-18, 10:20 AM
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Check Valve, How Tight?

Putting my Central Pneumatic(Harbor Freight 90234) back together and I am perplexed about how tight the check valve is supposed to be. Upon starting to thread it in it goes smoothly, but when it is slightly snug I can use an open ended or adjustable wrench. I can turn it a bit more but it gets to the tightest point that it wont line up in the proper position for the copper tubes. Just how much am I suppose to lean on this thing. I am afraid to destroy the treading on either the valve stem or the tank hole.
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Old 07-24-18, 11:01 AM
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It's pipe thread... pipe thread gets bigger as it turns on the make end, smaller as it turns on the female end. This makes it seal tightly. Put it on good and tight, not enough to break or twist anything though. I don't know how hard you are turning it but generally if it isn't tight when it lines up, you give it another turn... carefully.

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