Running Propane Gas Line

[S. Heisley]

Ageless wrote:

And if you used threaded pipe; never, ever use teflon tape for the fittings!!!

When I called the propane company and was asking all my questions about installation, they told me to use teflon tape and then put gas pipe dope over it.

[Dale M.]

Technically, standard teflon tape (white) should not be used for gas fittings. In some parts of the country, it is a code violation. There is a yellow teflon tape available for tapered pipe threads, but let me clarify what tapered threads are vs flared fittings...

Tapered is the standard thread (NPT or National Pipe Thread) on galvanized or black iron pipe. This is where you would typically use Teflon tape (of the correct color).

And many applications they use GREEN tape of oxygen and it goes on and on....

Basically (code violations aside) there is no difference whether the tape is white, yellow, green, red..... Its only the pigment used in tape manufacturer ..... The chemical and physical properties of tape is the same...

Dale

[Dale M.]

Ageless wrote:

And if you used threaded pipe; never, ever use teflon tape for the fittings!!!

When I called the propane company and was asking all my questions about installation, they told me to use teflon tape and then put gas pipe dope over it.

That's bizarre. Putting pipe dope over tape connection serves no purpose.... It a either/or situation as both act as sealers ....

Dale

[48Rob]

Basically (code violations aside) there is no difference whether the tape is white, yellow, green, red..... Its only the pigment used in tape manufacturer ..... The chemical and physical properties of tape is the same...

Dale

Dale,

Pretty much, though the white is the thinnest of the above mentioned tapes.
Yellow is thicker, and is often recommended for gas lines because a thicker tape will help seal the joint better...though proper use of the material (number of wraps, application method) no matter the thickness, will create a leak free joint.
Perhaps the propane company suggested the use of dope on sealer to account for potentially improperly applied tape because they assume the phone question is coming from a novice?

Rob

[S. Heisley]

48Rob wrote:

Perhaps the propane company suggested the use of dope on sealer to account for potentially improperly applied tape because they assume the phone question is coming from a novice?

Ah, yes...That I am! Good point!

[Mike_La]

OK, here we go.

Per ASTM (American Society of Testing & Materials) Standards we must use a thread sealant on all NPT (National Pipe Taper) Threads & fittings. The type of thread sealant is selected for compatibility with the material that the pipe will be conveying. In residential service the use of NPT joints is normally limited to water, natural gas, propane gas, #1 & #2 heating oils and occasionally low pressure steam, refrigerants or high-pressure air in a shop compressor system.
TEFLON TAPE:

When PTFE (Teflon) tape first became available they only made it in the common single density type, which we commonly find in the hardware and home supply stores. Later they began making a double density version, which was twice as thick. Many state and local codes then adopted the double density type as mandatory when making connections for natural gas however since both products were the same color (white) it was difficult for inspectors to be sure which product had been used. PTFE tape is now made in numerous varieties and they have issued a color standard to determine which type should be used.

WHITE-Single density- should only be used on NPT threads up to 3/8 inch.
YELLOW- Double Density- yellow double density is often labeled as "Gas type"
RED-Triple Density: (Note-the container is red but the tape itself appears as a pale pink color). Presently required on all joints ½" diameter or greater.
GREEN- Oil Free PTFE tape- Required for use on all lines conveying oxygen (I.E. –medical oxygen or welding oxygen lines).
COPPER COLOR- contains granules of copper and is to be used as a thread lubricant but is not approved as a thread sealant. (Generally it is used as a thread lubricant on bolts or pipe threads for mechanical applications where no physical seal is required.)

PTFE tape is only approved as a thread seal when applied correctly. To apply you begin at the end of the pipe and wrap the tape under tension in the direction of the thread turns. Each successive layer should overlap the previous layer by ½ to 2/3 and continue wrapping until the entire threaded portion of the pipe is covered. (Minimum of 3 full turns).

[Miriam C.]

Great Post Mike! Gotta love this group.

[Dale M.]

Personally I always have trouble with the Teflon tape no matter how consciously I am about applying it.... Got to love the fool proof quality of pipe dope.... beside I only rarely plumb for propane and mostly do water around the property....

Dale

[Steve_Cox]

KEY-TITE my favorite gas line sealant.

This viscous sealant cannot be equaled for leak proof sealing of threaded, flanged and gasket joints. Use Key-Tite® in flow lines for hot and cold water, aqueous solutions, low pressure steam slurries, natural and manufactured gases, compressed air, filled products*, dilute acids and caustics, and alcohols. Key-Tite® is dark green and consists of vegetable and mineral oils and prime and extender pigments, plus an anti-oxidant. Key-Tite® contains no lead or other toxic ingredients, and will not affect the taste or color of water or any other potable liquid.

[Mike_La]

KEY-TITE my favorite gas line sealant.

This viscous sealant cannot be equaled for leak proof sealing of threaded, flanged and gasket joints. Use Key-Tite® in flow lines for hot and cold water, aqueous solutions, low pressure steam slurries, natural and manufactured gases, compressed air, filled products*, dilute acids and caustics, and alcohols. Key-Tite® is dark green and consists of vegetable and mineral oils and prime and extender pigments, plus an anti-oxidant. Key-Tite® contains no lead or other toxic ingredients, and will not affect the taste or color of water or any other potable liquid.

This is what's used in the Refinery I work in, and it works great. In fact, liquid pipe dope is the only pipe thread seal that can be used there.