CSST piping is recognized by code and certifying bodies responsible for approving material used in piping gas into residential and commercial buildings. It is important to note that rigid copper and black iron pipe—which is usually imported from foreign manufacturers without quality control—is not tested nor listed to any national standards for gas piping.
CSST piping is accepted by model codes including the National Fuel Gas Code (NFPA-54), International Fuel Gas Code (IFGC), and Uniform Plumbing Code (UPC). Additionally, certain brands of CSST are Factory Mutual (FM) listed for seismic resistance. CSST is approved for use in all 50 states.
CSST piping sold in the U.S. is also listed to ANSI LC 1-2005. The ANSI LC-1 product standard lists a number of stringent material and performance testing requirements to assure that the product can demonstrate its use as a flexible piping product. These tests include:
Environmental resistance (resistance to corrosion and freeze/thaw)