Material CSST


CSST (Corrugated Stainless Steel Tubing) is manufactured from ASTM A240 300 series (type 304) stainless steel. It is comprised of flexible corrugated stainless steel tubing with a polyethylene jacket. The jacket gives the tubing many favorable qualities including UV, chemical, and fire resistance. Many manufacturers use a polyethylene jacket that has an ASTM E84 rating of 25 for flame spread and 50 for smoke density. This allows it to be used in plenums and in fire rated construction. Currently this material is used only in distribution systems for natural gas and propane within a structure.

CSST complies with ANSI LC-1 Standard for Fuel Gas Piping*. This standard applies to piping systems rated at 5 psi, not to exceed 6.5 psi, or rated at 25 psi, not to exceed 30 psi.

CSST is available in 3/8”, ½”, ¾”, 1”, 1-1/4”, 1-1/2”and 2”. It is also sized by EHD (equivalent hydraulic diameter).  EHD is a theoretical size, which reflects the hydraulic performance or efficiency of the tubing. EHD may vary depending on the manufacturer. For instance, ½” CSST may be sized as 16 EHD from one manufacturer and 18 EHD from another.

CSST is sold in stock rolls varying in length from 50’ to 1500’ depending on the size of the tubing. Custom lengths are also available.

*The American National Standards Institute



Fuel Gas

Fuel gas systems convey natural gas or propane for laboratories, cooking, space heating, and...