CSST History
Spools of CSST  
CSST was developed in Japan in the 1980s. It was developed as a safety improvement over rigid black iron gas pipes that often failed and started fires during earthquakes. The flexible nature of the CSST system allows it to handle seismic activity without leaking gas.

In the early 1980s, the Gas Research Institute initiated research into the use of CSST systems in the U.S.; listing processes, and code approvals needed to be developed and accepted by regulatory bodies. The American National Standards Institute performance specification, AGA LC-1 1987 "Proposed Standard for Interior Fuel Gas Piping Utilizing CSST" was released in 1989.

Sales of CSST in the U.S. began in 1990 with approximately 100,000 ft. sold. Use of CSST grew in the U.S. as contractors quickly discovered it could be installed in 1/3 the time of rigid black iron pipe systems. Beyond the time saved on installations, contractors and code officials appreciated the reduction of fitting joints in a flexible gas piping system. Joints are areas for concern in gas piping systems as they represent potential leak paths. Flexible CSST systems have approximately 75% fewer fitting joints than rigid black iron pipe systems.

All CSST manufacturers expressly added the bonding and grounding procedure to their installation requirements in August 2006. This improved safety installation requirement reduces the likelihood of an electrical surge that can potentially cause a fire.

More than 800 million feet of CSST gas piping in approximately six million homes has been installed in the U.S. since 1990.