Gas System Thread Sealant?

**wbmiller3** · 07-30-2006, 04:28 PM

When I opened up the tank valve on one of the propane tanks this weekend there was a big leak at the "hand-tighten" fitting. I bought a new hose seqment with fitting from a handy dealer, but when I took the old one off, it appeared that the brass threads were sealed with a red substance. Anybody know what this is, and whether it is OK to use Teflon tape instead?

Thanks in advance!

Leslie & Nick · 07-31-2006, 05:42 AM

I've used Teflon tape for gas connections. However this tape was made for gas work and is yellow in color, as opposed to the more commonly used white tape used for plumbing applications. The yellow tape seems to be thicker than the white.

Speckul8r · 07-31-2006, 09:07 AM

The "Hand tighten" fitting on the propane tank shouldn't need any tape. It tightens down using a flare fitting which should seal it. If it isn't sealing, look for dirt or a burr on either one of the fittings.

07-31-2006, 09:40 AM

This may be old news-or even old proceedure-but once upon a time LP filling stations used to clean the threads of the tanks with a red solution before attaching their hoses. This left a red ring on the tank. I haven't seen this proceedure used since I was very little--over 40 years ago!

07-31-2006, 10:49 AM

(The "Hand tighten" fitting on the propane tank shouldn't need any tape. It tightens down using a flare fitting which should seal it. If it isn't sealing, look for dirt or a burr on either one of the fittings.)

I think they're talking about the threads on the end of the hose, not the "hand tighten" fitting itself.

Speckul8r · 07-31-2006, 10:52 AM

Sorry, I took it literally.

07-31-2006, 11:00 AM

When I worked in the RV business, we always used teflon paste on the gas fittings. It's available in small tubes at Home Depot or Lowes - probably even Wally World, but I've never checked. ( A word of caution, when using teflon tape or teflon paste, be careful not to over tighten the fitting. If you do the fitting can crack and you'll have your leak again.)

**wbmiller3** · 07-31-2006, 07:27 PM

Thanks to all, I will look for the yellow Teflon tape. Sorry my post wasn't clear, it's the threaded fitting where the hose screws into the regulator that I am trying to seal.

Speckul8r · 08-01-2006, 11:34 AM

Looked at this fitting a few minutes ago and it, too, is a flare fitting. So , I'll say it again, it should not need any sealant. If it's not sealing properly, there is a problem that needs to be fixed.

**wbmiller3** · 08-01-2006, 07:43 PM

Quote:

Originally Posted by Speckul8r

If it's not sealing properly, there is a problem that needs to be fixed.

Yep, that's why I'm replacing it.

Incidentally, went shopping for brass fittings today, and there was a sign over the display rack saying not to use Teflon tape on them.

Thanks again.