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Teflon tape


asihi
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I have a question. A friend of mine asked me to look at an inspection report for a house that he's selling. Here's what the inspector wrote regarding teflon tape:

"White Teflon tape used on gas pipe connections is forbidden, because small pieces of tape can get shredded during assembly, break off and flow downstream to block the gas valve. There's a special yellow Teflon tape and compounds available for gas piping and you should have this condition evaluated by a licensed plumber-water heater supply line"

It sounds like he's talking about the gas line to the water heater, which I'm assuming is black iron. I have never heard of teflon tape being illegal.

Am I missing something or is he making this up?

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I have a question. A friend of mine asked me to look at an inspection report for a house that he's selling. Here's what the inspector wrote regarding teflon tape:

"White Teflon tape used on gas pipe connections is forbidden, because small pieces of tape can get shredded during assembly, break off and flow downstream to block the gas valve. There's a special yellow Teflon tape and compounds available for gas piping and you should have this condition evaluated by a licensed plumber-water heater supply line"

It sounds like he's talking about the gas line to the water heater, which I'm assuming is black iron. I have never heard of teflon tape being illegal.

Am I missing something or is he making this up?

I know you know this, but ask the inspector to cite the authority that forbids it. (Forbidden sounds so ominous, doesn't it? Kinda like a skull will glow and shoot death rays at the culprit.)

I used to write that up 15 years ago or so...heard it somewhere. Never heard of a problem, though, so I quit worrying about it.

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There is a tape designed for gas piping, and it is yellow. IIRC, the reason for using it has more to do with proper thread lubrication and spark hazards than with the white stuff dislodging and clogging gas valves. If I were installing gas lines I'd use the right stuff (dope is still better than tape IMHO), but if I saw white tape on an inspection I'm not sure I'd make a big deal of it. It kind of depends on what else was wrong.

Tom

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I frequently find "White" Teflon tape on gas pipe joints, particularly on Water Heater gas supply pipes. Until I'm told otherwise, I will continue to write up the use of White (single density) tape used on gas pipe joints.

If I notice that the tape is yellow or a light pink, then I don't write it up. A while back I found this excerpt on one of the Plumbing Forums:

When double density PTFE tape first came on the scene it was also white, packed on a white spool and primarily only marketed to professional tradesmen through the plumbing or HVAC supply houses. Most plumbers quickly adopted it because it was quicker and easier to apply and made a much more reliable joint. Shortly thereafter many gas codes were amended to require the use of double density tape on gas joints. Once the codes were changed they began making the double density tape yellow so that the inspectors would have a visual indicator that the correct tape had been used, thus to this day the yellow double density tape is often labeled as "Gas Tape".

As the PTFE tape industry evolved into more products they adopted a standardized color code.

WHITE- Single density tape to be used as a thread sealant on NPT (National Pipe Taper) threads which are equal to or less than 3/8".

YELLOW-Double density "Gas tape" suitable for NPT threads equal to or greater than 1/2" but not more than 2"

Red- Triple density tape suitable for NPT threads equal to or greater than 1/2" but not more than 2". (NOTE-The package is a red spool with a red cover ring and plainly labeled 'triple density", but the tape itself appears as a pale pink color).

GREEN TAPE- Listed as "OXY/MED tape"-certified oil free to be used on lines conveying oxygen and some specified medical gasses.

COPPER TAPE- Contains copper granules and is certified as a mechanical thread lubricant but is not certified as a thread sealant.

Kevin

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PTFE thread seal tape (Teflon is a trademark of Dupont) that's color coded yellow indicates that it is high density as compared to the standard white. It's UL listed and AGA aproved for natural gas and LPG. I don't think it has anything to do with "small pieces... shredded during assembly". I think it's manufactured and tested to be more resistant to chemicals associated with fuel gas, hydrocarbons and solvents.

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I've been calling the use of teflon tape on gas connections for a long time too. I had a buddy call me and ask what code section he could refer to.

In the NJ IRC, section G2414.9.3 States Thread compounds- Thread (joint) compounds (pipe dope) shall be resistant to the action of liquefied petroleum gas or to any other chemical constituents of the gas to be conducted through the piping.

However, when I call the DCA for clarification, they could find no section that prohibits teflon tape, so , like Jerry, i stopped calling it out too.

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I have a question. A friend of mine asked me to look at an inspection report for a house that he's selling. Here's what the inspector wrote regarding teflon tape:

"White Teflon tape used on gas pipe connections is forbidden, because small pieces of tape can get shredded during assembly, break off and flow downstream to block the gas valve. There's a special yellow Teflon tape and compounds available for gas piping and you should have this condition evaluated by a licensed plumber-water heater supply line"

It sounds like he's talking about the gas line to the water heater, which I'm assuming is black iron. I have never heard of teflon tape being illegal.

Am I missing something or is he making this up?

It's a good catch on the inspector's part but his reasoning is flawed and confused. There is nothing illegal about white teflon tape, it's not designed for gas piping.

Pipe joint tape comes in different colors such as white, rose (pink) or yellow.

Each have a different application. Personally I use the white for finish work and pink for boilers, irrigation, or rough work where the joint is not visible; the tape is thicker. The yellow is known as Gas-Tape, and is designed to resist petroleum degradation.

Here is how the specs read on the spool.

For use on threaded metal pipe joints (not exceeding nominal pipe size 3) in assemblies handling natural gas and methane propane and butane and petroleum distillates (pressures not exceeding 15,514 kPa (2,250 psi)

In so far as his statement regarding the shredding and possible blockage of valves, that's an installation issue, regardless of color, that doesn't apply to the concern at hand.

"......you should have this condition evaluated by a licensed plumber-water heater supply line." There is nothing to evaluate, consult a competent and licensed gas fitter to correct this installation....Overtime the affected joints may fail and leak gas and go BOOM and you might never see your dog again......etc.[:-monkeyd

Technically it's known as Thread Sealing Tape.

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There are several seal compounds on the market and the one I use is Jet-Lube No. 60, it's non hardening. Its function is to cool, lubricate and seal a threaded pipe joint without galling and minimizes stripping, it also has an anti-rust additive.

When I work with my gas fitter, he insists I tape AND dope all joints.

At the risk of repeating myself; the white joint tape is NOT allowed on gas lines.

Also be careful, over time the yellow tape will fade and turn white or light yellow that could be mistaken under certain lighting conditions.

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There are several seal compounds on the market and the one I use is Jet-Lube No. 60, it's non hardening. It's function is to cool, lubricate and seal a threaded pipe joint without galling and minimizes stripping, it also has an anti-rust additive.

When I work with my gas fitter, he insists I tape AND dope all joints.

At the risk of repeating myself; the white joint tape is NOT allowed on gas lines.

Also be careful, over time the yellow tape will fade and turn white or light yellow that could be mistaken under certain lighting conditions.

In your report do you recommend that a fitter/plumber takes apart every joint with white tape, remove the white tape, and then uses pipe dope or yellow tape?

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Consult a competent and licensed gas fitter to make the necessary repairs.

It's not my function to recommend a method of repair and I don't want the liability.

Now, if you ask me off the record, what do you think I'd tell my client?

The yellow tape was developed for a reason, mainly because it was found that overtime the white tape deteriorated when exposed to hydrocarbons. That's not to say that it will leak in the future but rather there is a chance that it might fail and for that reason I make a note of it in my report.

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Consult a competent and licensed gas fitter to make the necessary repairs.

It's not my function to recommend a method of repair and I don't want the liability.

Now, if you ask me off the record, what do you think I'd tell my client?

The yellow tape was developed for a reason, mainly because it was found that overtime the white tape deteriorated when exposed to hydrocarbons. That's not to say that it will leak in the future but rather there is a chance that it might fail and for that reason I make a note of it in my report.

I'd be more worried about it muckin' up a gas valve than a joint leaking. We've been putting pipe joints together long before teflon tape was ever invented.

The yellow tape was developed for a reason, mainly because it was found that overtime the white tape deteriorated when exposed to hydrocarbons.

Or to sell more tape.

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When I work with my gas fitter, he insists I tape AND dope all joints.

At the risk of repeating myself; the white joint tape is NOT allowed on gas lines.

Rob, I'm not doubting your knowledge or your experience with this stuff, but when you say white joint tape is not allowed on gas lines are you talking about the manufacturers specs or is it code? What about this stuff? http://www.sealtape.com/ptfe_hdwhite.html

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My two cents... Codes don't usually "forbid" specific materials. They would have to out-guess every possible weird substance. Lard anyone? We are normally left with "approved" materials or "to manufacturers' specs". As Westape (from the link above) also makes a UL Yellow Gas Line Tape ( http://www.sealtape.com/ptfe_yellow.html ) I suspect they would specify that for gas lines.

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My two cents... Codes don't usually "forbid" specific materials. They would have to out-guess every possible weird substance. Lard anyone? We are normally left with "approved" materials or "to manufacturers' specs". As Westape (from the link above) also makes a UL Yellow Gas Line Tape ( http://www.sealtape.com/ptfe_yellow.html ) I suspect they would specify that for gas lines.

You're correct, they do sell the yellow gas line tape, but that doesn't answer the question of the white tape not being allowed.

We have so many other things to look for, adding something like this would be far down the list.

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Some of the older water heater/furnace installation manuals said: When installing gas piping, use a pipe joint compound that is resistant to the action of propane (LPG) gases. Apply the compound to male threads only. Do not apply the compound to the first 2 threads. Do not use TEFLON tape. Do not use pipe joint compound or TEFLON tape on the union connection.

Then I started to see installation manuals say: Compounds used on the threaded joints of the gas piping must be resistant to the action of liquefied petroleum gases/propane gas.

Now I see: Use pipe joint compound or Teflon tape marked as being resistant to the action of petroleum [Propane (L.P.)] gases.

I never see Teflon tape being used in my area. Based on what I have read, I don't think I would call it out.

Jeff Euriech

Peoria Arizona

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When I work with my gas fitter, he insists I tape AND dope all joints.

At the risk of repeating myself; the white joint tape is NOT allowed on gas lines.

Rob, I'm not doubting your knowledge or your experience with this stuff, but when you say white joint tape is not allowed on gas lines are you talking about the manufacturers specs or is it code? What about this stuff? http://www.sealtape.com/ptfe_hdwhite.html

Its description sums it up.

"It is widely used by plumbers for General Water Plumbing applications."

Also have a look at the compatibility chart bottom right corner.

Different applications require specific thread sealing tape designed for that purpose. Look around the site, you'll understand what I mean.

Bottom line, not all tapes are equal. The white tape, regardless of thickness, is not designed for hydrocarbons, if you have natural gas you need to use the correct tape (UL Yellow Gas).

Back to the original question:

"Am I missing something or is he making this up?"

He's not making up anything. He recognized the white tape but failed to explain why it was wrong. I wouldn't fault him for that.

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When I work with my gas fitter, he insists I tape AND dope all joints.

At the risk of repeating myself; the white joint tape is NOT allowed on gas lines.

Rob, I'm not doubting your knowledge or your experience with this stuff, but when you say white joint tape is not allowed on gas lines are you talking about the manufacturers specs or is it code? What about this stuff? http://www.sealtape.com/ptfe_hdwhite.html

Its description sums it up.

"It is widely used by plumbers for General Water Plumbing applications."

Also have a look at the compatibility chart bottom right corner.

Different applications require specific thread sealing tape designed for that purpose. Look around the site, you'll understand what I mean.

Bottom line, not all tapes are equal. The white tape, regardless of thickness, is not designed for hydrocarbons, if you have natural gas you need to use the correct tape (UL Yellow Gas).

Back to the original question:

"Am I missing something or is he making this up?"

He's not making up anything. He recognized the white tape but failed to explain why it was wrong. I wouldn't fault him for that.

Rob I don't fault this guy for anything. I have no interest in this place, but I still would never call this out. It may technically be wrong, but the day I have to check compatibility charts for everything in the building is the day I quit. BTW, natural gas is on that chart.

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You mean this chart?

Chemical Compatibility

Polytetrafluoroethylene (PTFE) is compatible with the following materials:

* Water (Regular White)

* Steam (Premium Pink)

* Air, compressed (Premium Grade)

* Alcohols (Premium Grade)

* Fatty Acids (Premium Grade)

* Kerosene (UL Yellow Gas)

* Natural Gas (UL Yellow Gas)

* Nitrogen (UL Yellow Gas)

* Acids, dilute (Premium Grade)

* Ammonia, liquid (Premium Grade)

* Cutting Oils (Premium Grade)

* Soap, Liquid (Premium Grade)

* Ethylene glycol (Premium Grade)

* Gasohol (UL Yellow Gas)

* LPG (Premium Oxygen)

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You mean this chart?

Chemical Compatibility

Polytetrafluoroethylene (PTFE) is compatible with the following materials:

* Water (Regular White)

* Steam (Premium Pink)

* Air, compressed (Premium Grade)

* Alcohols (Premium Grade)

* Fatty Acids (Premium Grade)

* Kerosene (UL Yellow Gas)

* Natural Gas (UL Yellow Gas)

* Nitrogen (UL Yellow Gas)

* Acids, dilute (Premium Grade)

* Ammonia, liquid (Premium Grade)

* Cutting Oils (Premium Grade)

* Soap, Liquid (Premium Grade)

* Ethylene glycol (Premium Grade)

* Gasohol (UL Yellow Gas)

* LPG (Premium Oxygen)

Got me on that one, Bob. I give up you win

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Isihi

This has nothing to do with winning.

You asked a reasonable question and hopefully got a reasonable answer, nothing more.

If you chose to disregard it or don’t’ think it’s relevant to your style of inspecting, then that’s fine too.

As I see it, you’re the winner, for now you have the answer to your question, reasonably priced, I might add.

Don't give up .... just yet

Rob

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  • 3 years later...

I hope all that think the tape being used on gas piping is irrelevant, please read on.

I am an New Jersey Lic Master Plumber. I am an authorized service agent for a major plumbing fixture manufacturer out of Wisconsin. A urinal flushometer pre-installed on the urinal was installed in a residence not yet occupied. The urinal flushometer started dripping as soon as water pressure was applied to put the unit in service.

Passing by before having the replacement parts I decided to stop in since the home was open still under construction in the finish phase.

I disassembled the components and found that a strand of teflon type white tape had followed the water flow thru the valve and remained across the seat and caused the water to drip past the spring loaded diaphragm that would normally stop street water pressure.

The pilot light on a gas regulator closes against a 1/4 pound of pressure.

Tape shreds will stop the diaphragm from fully closing creating an explosive atmosphere.

NOT WORTH USING TAPE ON GAS PIPING.

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I have a question. A friend of mine asked me to look at an inspection report for a house that he's selling. Here's what the inspector wrote regarding teflon tape:

"White Teflon tape used on gas pipe connections is forbidden, because small pieces of tape can get shredded during assembly, break off and flow downstream to block the gas valve. There's a special yellow Teflon tape and compounds available for gas piping and you should have this condition evaluated by a licensed plumber-water heater supply line"

It sounds like he's talking about the gas line to the water heater, which I'm assuming is black iron. I have never heard of teflon tape being illegal.

Am I missing something or is he making this up?

Although many people seem to feel that Teflon Tape is not approved, I recalled reading years ago that it is ok to use. I just looked at a National Fuel Gas Code handbook (1992). In reference to section 2.6.7(d), which refers to using pipe dope suitable for use with gas, The handbook says: "This requirements does not prohibit the use of teflon tape as a pipe dope. When using teflon tape extreme caution must be taken to ensure that tape fragments do not enter the piping system where they can block orifices and restrict flow. Many gas piping installers do not use teflon tape for this reason."

I do not know what later editions of the code say, but from that wording I assume it is or was permitted. There is no mention of different types of teflon tape. I wonder whether the colors have more to do with marketing than chemical resistance.

I also looked at a chemical compatibility chart on for Teflon. It lists Teflon as being compatible with Liquefied Petroleum Gas. The IRC says that pipe seals for gas piping must be compatible with LPG.

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