Arc-Resistant CSST
In the 2018 edition of NFPA 54, the use of arc-resistant CSST (black jacket) had been approved in section 7.12.3. The new code allows for this product to be treated like non-CSST pipe and tubing for bonding purposes, only requiring bonding to an effective ground fault current path. The arc-resistant jacket does not rely on bonding to reduce electrical arcing but is designed to absorb and dissipate the energy within the jacket.
The Missouri Propane Safety Commission had not yet adopted the new edition as it is a work in progress. Until the new edition is adopted, we will allow the use of the new product using the Equivalency code 1.4 in NFPA 54. From a safety perspective, arc-resistant CSST is considered equivalent to bonded CSST when installed properly per manufacturer’s instructions.
The new code in 7.12.3 states; “CSST listed with an arc-resistant jacket or coating system in accordance with ANSI LC 1/CSA 6.26 Fuel Gas Piping Systems Using Corrugated Stainless-Steel Tubing, shall be electrically continuous and bonded to an effective ground fault current path. Where any CSST component of a piping system does not have an arc-resistant jacket, the bonding requirements of 7.12.2 shall apply. Arc-resistant jacketed CSST shall be considered bonded when it is connected to appliances that are connected to the appliance grounding conductor of the circuit supplying that appliance.”