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Stuck NPT fitting in pressure regulator

Stuck NPT fitting in pressure regulator

Stuck NPT fitting in pressure regulator

(OP)
I have a pressure regulator that has two female NPT ports (inlet and outlet). Silly me forgot to put teflon tape on the male NPT fitting and tightened the fitting all the way in.

Now it won't budge when I try to pull it back out. I don't want to buy another regulator as this one is relatively expensive. The fitting I can replace anytime. Both the fitting and the regulator are stainless steel if that helps.

Thanks!

RE: Stuck NPT fitting in pressure regulator

You are most likely have thread galling, if you do, Forcing the fitting out will gall the threads even more.
You may be forced to clamping the fitting in a vice, drilling out the excess pipe, then pulling the final spiral of pipe out of the threads.
Then you are faced with the problem of cleaning the shavings and swarf out of the regulator body, so you do not get it in the valve seats.
B.E.

The good engineer does not need to memorize every formula; he just needs to know where he can find them when he needs them. Old professor

RE: Stuck NPT fitting in pressure regulator

Unfortunately, when galling occurs, there is very little you can do, quite often you end up damaging the thread beyond repair.
However, you could try a trick I used before, with more than 50% success. Try to cool down the fitting or even freeze it if you can, then try to turn VERY slow the fitting anticlockwise. The lubrication is not going to help much, because it won't penetrate between the seized thread surfaces anyway.
Good luck,
gr2vessels

RE: Stuck NPT fitting in pressure regulator

Does it leak, if not why worry about removal? If it leaks try wicking something like loctite between the components.

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

RE: Stuck NPT fitting in pressure regulator

(OP)
Artisi: It does indeed leak even when it was "bottomed out" or tightened as much as possible originally.

gr2vessels: I will try that trick.

RE: Stuck NPT fitting in pressure regulator

If you're forced to drill it, use a left hand drill bit. That way the fitting may spin out as soon as the stored strain energy is reduced, and there may be a usable amount of female thread remaining.

If you can, clamp the regulator to something overhead when drilling it, so the chips fall out. ... onto your safety goggles.

Mike Halloran
Pembroke Pines, FL, USA

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