Material CSST

CSST (Corrugated Stainless Steel Tubing) is manufactured from ASTM A240 type 304 stainless steel and complies with ANSI LC-1 Standard for Fuel Gas Piping. It is comprised of the flexible corrugated tubing and 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 materials only use is in distribution systems for Natural Gas and Propane within a structure.

The industry has certified CSST for use up to 5psi, although it should be known that in certain situations, and with proper documentation, CSST can be approved for use up to 25psi.

CSST is available in 3/8”, 1/2”, 3/4”, 1”, 1-1/4”, 1-1/2”and 2”, however is sized by EHD (equivalent hydraulic diameter).  EHD is a theoretical size, which reflects the hydraulic performance 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 rolls varying in length from 50’ to 1500’ depending on the size of the tubing.


Fuel Gas

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