@$!*ing NPT fittings on my regulator

[EricsZ28]

I can't get my NPT fittings on my Mallory regulator to seal. I've tried both teflon paste and teflon tape. They both leak. I've swapped out fitting as well. I have an ever present film of gas that runs down the sides of the regulator from the inlet and outlet. The return line and the NPT plugs seem to seal OK.

Has anybody used this stuff to seal fuel line fittings? I've used it in the past for other stuff and it seals real well IMHO.

Thoughts?

I have this regulator:
http://www.summitracing.com/parts/MAA-4309/

This sealer:

 

[Doug Jaynes]

is the housing cracked ? have a good close look at it under good light

Doug

 

[EricsZ28]

Nope, it does not appear to be cracked.

 

[CamaroMan79]

I had that same regulator and it cracked on me, so be sure.

 

[muscl car]

we ran those regulators on our dirt track cars and both times we used them the threads cracked in the housing causing it to leak

 

[EricsZ28]

crap. I'll check it again.

 

[Cardinal]

Are they NPT (National Pipe Tapered) or NPS (National Pipe Straight). IF they are NPS, you can tape, dope, scream and yell, but NEVER get them to seal. A NPS has a seal that goes between the face of the two objects, in this case the regulator with a female thread is one object and the fitting with a male fitting in the other.

http://www.swagelok.com/fittings/in_search_of_the_ideal_fitting.htm

 

[mrdragster1970]

.

As mentioned, make sure what threads you have. My old regulator use a NPT, fitting. My new regulator uses a ORB fitting.

Ok, I guess I should have looked at the link 1st. That is definitely a NPT fitting.
I had that regulator a long time ago, and gave it away. I had trouble getting it stable.
As mentioned, check the threads and get them clean with a pick or ??
If there's no cracks, I would use an extra thick layer of tape and carefully try again.
It's very rare a NPT won't seal unless there's an issue, crack, burr, bad machining??

Make sure the fitting is clean, and no issues also.

.

 

[EricsZ28]

For those who have had these crack - can you recall where you found the cracks?

I'm sitting here looking at my regulator. The threads that did seal well (the return port) look pristine. The threads that were leaking look pretty rough - and they always have. I don't see any cracks in the housing.

I think you're right - it must be the threads... I've cleaned them and resealed them at least four or five times now...

Let's see how good the 1 year warranty is.

EDIT: Summit said "we're putting a new one in the mail, send us back the old one when you get the new one". Just to be safe, I bought all new NPT/AN adapters and plugs. Summit rocks

 

[mrdragster1970]

.

Good deal, alum threads have screwed me over plenty over the years.
Good luck, and make sure you don't over tighten, and stress anything.

.