Question about Teflon tape for air compressors

Nov 19, 2005 41 Replies

A few months ago I bought a portable air compressor, and it came supplied with a roll of teflon tape. When assembling all of the various couplers/hoses/tools, I found that I needed to use copious amounts of that tape on all the threads in order to get anything to hold pressure. So far, so good.



This morning I was reading a review of a large Porter Cable compressor on Amazon, and the reviewer made the following statement regarding a leaking connector:



"After depressurizing the tank, I removed the factory compound from the threads and put on fresh joint compound (teflon tape is a no-no for air applications)."



So my question is, why is Teflon tape a bad idea for compressors? It's worked like a charm for me so far.



Thanks in advance.



| So my question is, why is Teflon tape a bad idea for compressors? | It's worked like a charm for me so far.

Little 'threads' of Teflon probably won't help air tools work better.

That said, I'll confess that I used the tape for the majority of my tool and hose couplings.

-- Morris Dovey DeSoto Solar DeSoto, Iowa USA

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On 11/19/2005 10:13 AM wood snipped-for-privacy@yahoo.com mumbled something about the following:

The person who made that comment has no clue. Teflon tape is as good (if not better than) teflon pipe dope for air applications. If you wind teflon tape wrong, it's a no-no in any application, as it can block air/water/fuel/etc passage. If you wind it correctly, it's preferrable to teflon pipe dope.

On 11/19/2005 10:17 AM Morris Dovey mumbled something about the following:

That works both ways for tape and dope. If improperly applied, both can allow pieces of tape or dope into the system and clog up air tools. Tape is easier to apply without allowing it into the system than is dope.

As do I, but I am careful to wrap the tape carefully to avoid having any tape extending into the air pathways. I also wrap in a direction that makes insertion tighten the wrap, rather than loosen. I usually peel the excess from the fitting when done - but I'm kind of anal...

I also cover my air inlets, insure there is no dirt in the coupler before connecting a tool, and oil my tools regularly.

I have never heard of any chemical reactions that would cause failure of either the compressor, hose or tools. But I could be in error. I would be interested in seeing reputable evidence supporting the magazine writer's phobia.

FWIW,

Greg G.

I'd accept the fact that PC _includes_ Teflon tape with the compressor kit that the Amazon reviewer has his/her head up the ol' arse.

Barry

It isn't - it works fine. You can even use it on oxygen systems.

You might need (or be required by local bylaws) to use the high density PTFE tape for sealing flammable gas systems in your locality (yellow spools in the UK) rather than the "water grade". The cost is only trivially more so many people only use the "gas grade" for everything.

Remember too that PTFE thread sealer tape is only useful on tapered threads, not parallel threads (there needs to be some compression) and it's certainly not useful on metal compression joints, metal face joints or around metal olives. If you're using parallel threaded pipe, use a liquid sealer that sets.

I don't dissagree with your conclusion, but by that analogy, including keys with a new car is not necessarily in the public's best interest.

Greg G.

Hmm... metal olives - quaint term. I believe I'll have one of those in my next Martini. Shaken, not stirred...

(I know what you are referring to, just never heard them called that before - you're in the UK, no?)

Greg G.

I use Teflon tape everyday at work. ( 31 years as a Pipe fitter). We use it on any threaded connection. On air lines, especially instrument air lines, you have to be careful not to allow any of the tape to extent over the ends of the threads. This could let lose pieces of tape come off and enter the air system. Lose pieces in the system can stop up air ports or any filters in the system. If you are concerned about this possibility you can buy liquid Teflon in a tube from HD or any hardware store.

In reality the Teflon in not a sealant. It is an anti-galling compound that keeps the male and female thread from galling together (welding together by the heat of friction) when you tighten the connection up.

Henry

The source of the comment should be enough to ignore it. Its a bogus comment. Even the idea of removing all the factory compound and redoing all the joints is weird. Did they repaint the compressor as well?

You'll do fine with Teflon. I believe the comment from the person who is a pipefitter is as well founded advise as you could get.

Bob

Never mind - I now notice you said "Amazon" --- 'nuf said.

Greg G.

Agreed, & same here; never had a problem with it & it's convenient when making changes/mods to my setups which I do occasionally.

So what do you call them in the USA ?

And what's a "Martini" Outside of M*A*S*H and Bond I think I've seen more of these as rifles than as drinks. Does anyone really drink them?

If installed properly there are no 'little threads' to get in the way. It should be installed 1 thread down from the end so there is no end overlap and 3 complete wraps in the opposite direction of the threads so it doesn't bunch up when twisted on. I've never ever had a problem using teflon tape for any thread sealing work, air, water, fuel or anything else I've used it on. John

Actually, I don't know. Are you talking about the flared part of a compression fitting?

Yes. People drink martini's.

No, those are "flares" - I think the terminology is the same. An olive is the loose ring that's used in some other types of joint. They can either be soldered in place (an old sort of flare) or they're sharp-edged and used on soft copper pipe with a compression fitting.

LOL. I didn't know they had a name. I've always called them "the compression ring". Let me check the Web.

Ahhhh....

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ring is the American jargon.

Adding "olive" to the same google search, produces some UK sites.

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= compression ring

BTW...it appears that

Spanner = Pipe wrench

I was thinking of basin c*ck couplings - something which is not seen much anymore. Could also be used for compression ring couplings.

A cocktail made of gin or vodka and dry vermouth.

Plutocrats love'em.

Greg G.

As do I. I ran a scuba shop for ten years in my first career, and teflon tape was commonly used throughout that industry for making high pressure air connections anywhere there wasn't already a captured o-ring. We used compression fittings a lot too.... either copper for up to 2500 psi and stainless steel for pressures up to 5-6000 psi. But we used teflon tape damned near everywhere. I never saw anyone use pipe dope for air fittings.

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