air compressor sealant

[Dave Fritz]

516990I'm putting an extension on the bottom of my air compressor so I can more easily drain the tank and remove moisture. The kit came with several adaptors, two of which are shown. All the male fitting have the red substance on the threads like those pictured. Is that the sealant? If so would you still use Teflon tape or some other sealant? Thank you so much for your help.

[Brian Elfert]

I never add sealant when the fitting already has sealant on it. I haven't had a leak with a fitting like that in my memory.

[Dave Fritz]

I never add sealant when the fitting already has sealant on it. I haven't had a leak with a fitting like that in my memory.

Thank you Brian.

[Bill Howatt]

Easy to re-do if it does leak and it most probably won't since I'd say that is sealant.

[Richard Coers]

Hardly a plumber alive that would put some pipe dope on every fitting. I watched a video where the plumber added pipe dope to that rubber donut that seals the toilet tank to the bowl. What's the harm?

[Bruce Wrenn]

Teflon tape ISN'T a sealant! Pipe threads are tapered, and seal by tightening. The Teflon tape "greases" the threads to allow for extra tightening. Some products (Rector Seal #5 as an example) are true sealants. Teflon tape isn't allowed on gas lines, as it can shred off and lodge in gas valves, causing them to leak. Yes. I know the big box stores sell the extra thick yellow stuff, but it still doesn't pass code. Holder of both P-2 and P-1 plumbing licensees in working years.

[Jason Roehl]

Teflon tape ISN'T a sealant! Pipe threads are tapered, and seal by tightening. The Teflon tape "greases" the threads to allow for extra tightening. Some products (Rector Seal #5 as an example) are true sealants. Teflon tape isn't allowed on gas lines, as it can shred off and lodge in gas valves, causing them to leak. Yes. I know the big box stores sell the extra thick yellow stuff, but it still doesn't pass code. Holder of both P-2 and P-1 plumbing licensees in working years.

Teflon tape is not banned in plumbing code around here. My (union) plumbers at work tape and dope gas pipe thread (any pipe thread to be sealed, really). If you hold the tape back one thread on the male threads, there is no way it's getting in the pipe. Three clockwise wraps, plus a thin, even layer of dope works every time.

Re: the original post...If it comes with sealant from the factory, I don't add it, unless it leaks after assembly.

[Ronald Blue]

Teflon tape is not banned in plumbing code around here. My (union) plumbers at work tape and dope gas pipe thread (any pipe thread to be sealed, really). If you hold the tape back one thread on the male threads, there is no way it's getting in the pipe. Three clockwise wraps, plus a thin, even layer of dope works every time.

Re: the original post...If it comes with sealant from the factory, I don't add it, unless it leaks after assembly.

I found the same thing. On the Oatey website they say their yellow PFTE tape is approved by code for use on natural gas lines and the yellow color is to make it easily identified.

[Michael Schuch]

The red substance is sealant and no additional sealant is necessary.

I have been using PTFE paste and only PTFE paste (water, air and natural gas) for the past 30+ years and have never had any leaks. Like said above it is as much about lubrication so the tapered threads mesh thoroughly and seal. PTFE paste is a lot like anti-seize in that it gets everywhere if not used sparingly.

Compressed air fittings that come with sealant on the threads I always use as is without additional sealant. A good tight fit is the key to no leaks on a "tapered" joint. Straight thread fittings require another sealing device like a rubber washer or compression ring and can be compromised if over tightened.

[Bill Howatt]

I know this is NOT the thinking on the PTFE taped joints and that the tape is performing as a lubricant to allow easier/more tightening of the tapered joint. But when I have taken such joints apart I see what I'll call compressed tape film coating the threads and to my way of thinking, that coating is contributing to sealing whether needed or not.
Just my thoughts.

[Mike Cutler]

Dave

The red sealant painted on those threads is fine. I know it feels dry to the touch, but once you begin to tighten it, the pressure and friction will make is conform to the threads. If you wrap it with teflon tape, you will be defeating the purpose of both products. "Generally" fittings that are pre treated with a sealant are a one time use fitting. They're not really made to be taken apart and reassembled multiple times
Teflon tape fills in the gaps between the machining differences of NPT fittings. It seals by filling the voids between the male and female NPT thread bodies. If you have fittings that may be taken apart for convenience, Teflon would be good for that application. If it's a fitting that you know will be undisturbed for years, a liquid sealant is a better choice. There are dozens, upon dozens, to choose from. Everyone has their favorite. It is hard to go wrong with Rector Seal.
Some the the "yellow" tape that you se in the big box stores is nothing more than colored teflon tape. Some of it though changes properties with the friction and heat generated by tightening two pipe fittings. Only way to know if it's allowed is to ask the local building inspector. However, if someone has a P1, and a P2, license, it's worth paying attention to what they're saying. ;)