Flexible Gas Line Underground

The line was run underground from the meter to the back patio grill. Probably about 20’. Did not see any reference in the IRC that hard pipe must be used. The only reference I saw was that the line must be buried at least 8". Can it be flexible line?


As long as the line is approved for underground, but I am betting it is not. I have never seen a yellow colored underground rate flex line before. You definitely need to check into it. Underground flex line is used all the time in my area.

This brand, WARDFLEX, says it may be installed underground with non-metallic conduit. But the ends should be sealed to keep out foreign matter and moisture.

*Page 55 *http://www.wardflex.com/images/design_install_guide.pdf](http://www.wardflex.com/images/design_install_guide.pdf)

Same with Diamond Back. http://www.mtlfab.com/media/L1627.pdf

DIAMONDBACK™ CSST shall not be buried directly in the ground or directly embedded in
concrete. When DIAMONDBACK™ is to be buried in the ground or embedded into concrete it
shall be routed inside of a nonmetallic conduit such as schedule 40 PVC. The conduit must be
sealed at any end that is exposed to outdoor weather conditions to prevent water from entering.
It is recommended that the CSST be one continuous piece inside the conduit from end to end.
CSST mechanical fittings are not allowed or permitted inside the conduit.


Here is the gastite brand instructions. They allow penetrations through wood, but must be protected through masonry. THey also manufacture a different covering for underground applications.

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If you want to sound *knowledgeable *and *professional *in your reports, call it Corrugated Stainless Steel Tubing (CSST). If you want to sound otherwise, call it flex pipe, flex line, yellow pipe, etc.

If you want to be knowledgable, then call the local rep. Many offer free classes and certifacations. I talked to the one for flextite since I was curious. He said they are having one soon. Only a couple of hours educational class. And then like magic wola you are certified…:shock::mrgreen:


"The WARDFLEX system described in this guide is intended primarily for interior use. See section for specifics on outdoor applications. [That section speaks about connections to outdoor appliances.]

General Provisions

WARDFLEX Mechanical Joint Fittings shall be protected from the effects of weather when used outdoors. After the connection is made to outdoor equipment the WARDFLEX Mechanical Joint Fitting shall be sealed by wrapping two layers of tape (e.g. PVC, Silicone) or by applying shrink sleeves (e.g. PVC, Polyolefin).

The following additional instructions regard the use of WARDFLEX in systems in which portions of the piping are exposed to the outdoors as required to make connections to gas meters or gas appliances,
which are attached to, mounted on, or located in close proximity to the building structure.

The external protective covering shall remain intact as much as practical for the given installation.

When installed along the side of a structure (between the ground and 6 ft.) in an exposed condition, the WARDFLEX must be protected inside a conduit or installed in a location which will not subject it to mechanical damage.

WARDFLEX shall not be buried directly in the ground or directly embedded in concrete (e.g. patio slabs, foundations or walk ways). When burial or embedment is required,WARDFLEX shall be routed inside nonmetallic (e.g.PVC) conduit. The conduit shall be sealed at any exposed end to prevent water from entering using double wrapped PVC tape or PVC shrink sleeves.

Don’t forget bonding requirements.

Good stuff Joe. The gastite is allowed in all weather applications. Go figure.

150’ 1" available due to order error out of mn. They want I restock and handle fee totaling 347.00 and idea who might be willing to get me out of this jam