PTFE tape gasoline resistant?

[seagull369]

The yellow kind, which I guess is just a thicker version of the white kind, says it's safe to use on "gas," but I imagine that refers to natural gas. Does gasoline, though, eat this stuff up?

 

[rlitman]

The yellow kind, which I guess is just a thicker version of the white kind, says it's safe to use on "gas," but I imagine that refers to natural gas. Does gasoline, though, eat this stuff up?

Teflon isn't eaten by any fuels that I am aware of.

Just to be clear, almost all teflon tape products are 100% teflon, and those are ALL equally immune to being broken down by gasoline, LP, NG, Jet A, etc.

The differences between the tape colors has most to do with the tape density, and thickness, with these two sets of exceptions: Green is special, because it is certified as oil free for oxygen service. Grey and copper colored tapes have nickel and copper particles for enhanced anti-galling properties, but inferior sealing properties.

 

[bwringer]

Insolubility is kinda Teflon's whole schtick...

https://www.calpaclab.com/teflon-ptfe-compatibility/

 

[engineer2]

What type of fitting on a gasoline engine (or whatever you are doing) requires Teflon tape? Most old fuel line fittings a flare types. The flare is the seal, not the threads.

 

[seagull369]

What type of fitting on a gasoline engine (or whatever you are doing) requires Teflon tape? Most old fuel line fittings a flare types. The flare is the seal, not the threads.

This is for a npt fitting on a generator gas tank. I'll probably end up using Permatex #2 non-hardening, but it got me wondering about the thread tape

 

[Dave455]

The yellow kind, which I guess is just a thicker version of the white kind, says it's safe to use on "gas," but I imagine that refers to natural gas. Does gasoline, though, eat this stuff up?

The yellow PTFE is sold here in the U.K. as “Gas Safe”, but that refers to “Gas” as in Propane, Butane etc, not “Gasoline”.

I imagine it’s the same stuff in the U.S. (as shown below) but given the differences in terminology I’m surprised they are not a bit more specific!

I’m not sure if it’s thicker, or a different composition?

One U.K. supplier says it’s suitable for “fuel oils” which implies Diesel or Kerosene, but not Gasoline.

 

[rlitman]

This is for a npt fitting on a generator gas tank. I'll probably end up using Permatex #2 non-hardening, but it got me wondering about the thread tape

Ah, makes sense. I've never used Permatex #2 on threads, but I do use it on water pump seals. I'd probably reach for my Rectorseal 5 for this, but there are lots of things I have rated for gasoline service.

 

[bamawildcat]

Rectorseal Yellow is what I would use.

 

[bonneyman]

Insolubility is kinda Teflon's whole schtick...

https://www.calpaclab.com/teflon-ptfe-compatibility/

Yeah, like it doesn't schtick to anything.

 

[Wrench97]

Worst part of Teflon tape on Fuel fittings is the part that breaks off and get stuck in the float.................I always use pipe dope like Rectorseal posted above.

 

[4xdog]

Worst part of Teflon tape on Fuel fittings is the part that breaks off and get stuck in the float.................I always use pipe dope like Rectorseal posted above.

Yep -- I don't use Teflon tape on anything where a loose piece could get into sensitive mechanics. That includes especially engine internals.

 

[ddawg16]

Guys....

Teflon tape is not a sealer. It's friction reducer which allows you to get more turns on the fitting. It's the tapered thread which provides the sealing.

The tape provides minimal sealing.

 

[DeeKay]

Guys....

Teflon tape is not a sealer. It's friction reducer which allows you to get more turns on the fitting. It's the tapered thread which provides the sealing.

The tape provides minimal sealing.

I've heard that from quite a few people, mostly engineers. In a perfect world yes that's how tapered pipe threads are designed to work given the threader makes a 100% perfect thread form. In the real world pipe dope and teflon tape does some of the sealing work.

 

[Renegade1LI]

Rectorseal Yellow is what I would use.

I agree we only use rector seal for diesel, gasoline & oils, usually #5, the key is well cut clean threads. A quick spray of brake cleaner works great.

 

[Showkey]

Worst part of Teflon tape on Fuel fittings is the part that breaks off and get stuck in the float.................I always use pipe dope like Rectorseal posted above.

X3 carb float seat stick drops gallons of fuel on the floor or in crankcase .

Guys....

Teflon tape is not a sealer. It's friction reducer which allows you to get more turns on the fitting. It's the tapered thread which provides the sealing.

The tape provides minimal sealing.

The fills the thread gap on tapered thread especially on poor quality China pipe and fitting. Extra thick tape extra raps is the new order of the day.

There some pipe and fittings that will never seal with filling the threads no mattter how tight.

 

[seagull369]

Thanks for all the great replies. I didn't realize Rectorseal (#5) was good on gasoline. I might just use that instead, since I have some already,

On a side note after reading the product descript, I didn't know the Rectorseal ISN'T recommended for use with ABS or CPVC.

 

[anndel]

I used to work for the Chevron Refinery repairing/refurbishing air pneumatic pumps and used to use the white version of the same PTFE tape. It worked well for everything I dealt with from crude oil to gasoline and naphta until the next pump rebuild about a year later.

 

[Hawke]

PTFE tape is the work of the devil. All its good for is lubricating taper threads (another design of Lucifier) and allowing them to overtighten and split housings, and or allow the fitting to vibrate loose. The only way to fit and seal a taper thread, is to use the correct Loctite thread sealant.

Ever wonder why you never see tape used on an aircraft or race car?

 

[ddawg16]

PTFE tape is the work of the devil. All its good for is lubricating taper threads (another design of Lucifier) and allowing them to overtighten and split housings, and or allow the fitting to vibrate loose. The only way to fit and seal a taper thread, is to use the correct Loctite thread sealant.

Ever wonder why you never see tape used on an aircraft or race car?

No....because those are different types of connections. They don't depend on the taper of the thread to provide sealing. Totally different animals...tape or dope would just cause problems.

 

[Renegade1LI]

Thanks for all the great replies. I didn't realize Rectorseal (#5) was good on gasoline. I might just use that instead, since I have some already,

On a side note after reading the product descript, I didn't know the Rectorseal ISN'T recommended for use with ABS or CPVC.

This is off the rector seal web site, good for pvc, do not use on abs or cpvc.
Applications
RectorSeal No. 5 is recommended for pipe made of galvanized steel, iron, brass,
copper, aluminum, stainless steel, polyethylene, reinforced fiberglass, and PVC. DO
NOT USE ON ABS OR CPVC.
RectorSeal No. 5 is recommended for pipe carrying:
• Acids, dilute
• Air, compressed
• Aliphatic solvents
• Ammonia – gaseous, liquid
• Caustics, dilute
• Cutting oils (low aromatic)
• Diesel fuel oil
• Gasohol (unleaded gasoline and 10%
alcohol)
• Gasoline (leaded and unleaded)
• Heating oils
• Helium, gaseous
• Hydraulic oils
• Hydrogen, gaseous
• Inert gases
• Kerosene
• Liquefied petroleum gases (butane,
propane, mixtures)
• Mineral oils
• Natural gas
• Nitrogen, gaseous
• Petroleum solvents
• Refrigerants
• Soap, liquid
• Steam
• Vegetable oils
• Water (hot or cold)

It's nice to have one sealant that covers such a wide range.

 

[rlitman]

Thanks for all the great replies. I didn't realize Rectorseal (#5) was good on gasoline. I might just use that instead, since I have some already,

On a side note after reading the product descript, I didn't know the Rectorseal ISN'T recommended for use with ABS or CPVC.

Rectorseal 5 doesn't have teflon on it, and I believe the "stiction" from ABS and CPVC is the issue. Rectorseal T plus 2 is teflon infused, and is rated for ABS and CPVC, though strangely, I don't see gasoline on the T plus 2 datasheet, whereas it is clearly listed on the 5.

 

[Renegade1LI]

I wouldn't recommend using abs or cpvc for gasoline or even pvc. If you are burying the pipe it should be frp, hdpe or ul971 flex pipe. Above ground usually sch 40 steel pipe is specd, A53 seamless.

 

[rlitman]

I wouldn't recommend using abs or cpvc for gasoline or even pvc. If you are burying the pipe it should be frp, hdpe or ul971 flex pipe. Above ground usually sch 40 steel pipe is specd, A53 seamless.

LOL, I can certainly agree to that. The point I was making is that Rectorseal dopes are not a one-size-fits-all product. But yeah, PVC and gasoline are kind of mutually exclusive, so it's not a problem.

However, for those crazy enough to need a one-size product for these edge cases, check out the Laco 41600 SLIC-TITE STIK. That stuff is rated for gasoline, and plastic pipes (yeah, probably not at the same time), and checks off more boxes on a single product than anything else I've seen.

 

[59 wagon man]

old school way was anything such as rectorseal, pipe dope , grape goo , whatever paste you wanted to use and spoolwick. cotton based thread wound into the threads and coated with any paste you wanted. more time consuming but never had a leak with thousands of joints made

 

[JRC3]

This thread hits home right now...I have a question...I'm going to use this on a plastic tank. I will use a regular nut on the inside, I also have another petcock and could use the nut and washer off that on on the inside. My question is, will that washer seal the threads or will I need sealant? I just can't imagine that washer smashing into the threads enough.

The project is an old Honda generator that's missing the tank, gonna use a regular red plastic gas can. Thanks.

Added another pic

 

[Wrench97]

That looks like it the seal to me, I would not put anything on it.

 

[rlitman]

That looks like it the seal to me, I would not put anything on it.

Correct. Thread sealant is for NPT (or BSP) tapered threads. It's really not appropriate anywhere else, though I've been known to coat metal-to-metal connections with a swipe of the above SlicTite crayon on flares and unions when they give me issues.

 

[Renegade1LI]

old school way was anything such as rectorseal, pipe dope , grape goo , whatever paste you wanted to use and spoolwick. cotton based thread wound into the threads and coated with any paste you wanted. more time consuming but never had a leak with thousands of joints made

Wanna laugh, I learned the hard way recently, like usual. Do not use wick with any oil! I have a fitter, who is a great pipe guy install fuel piping for new boilers in a school. Well somehow he thought that wick would leak proof it, 6 months later every joint leaked, had to reseal every joint. The wick works just like in a lamp, wicks the oil right through the threads. With water it swells up tight, not oil, he truly earned his nickname, leakum.