2018 International Existing Building Code (International Code Council Series) 1st Edition

This code establishes the primary guidelines for the safe design and installation of fuel gas systems and gas-fired appliances, combining specific technical requirements with broader performance-based standards. A notable update introduces a new section covering arc-resistant corrugated stainless steel tubing (CSST). The code now permits the use of Schedule 10 steel pipe, a change from previous versions that allowed only the thicker Schedule 40 pipe.

While Schedule 10 pipe may be joined using welding, brazing, flanged connections, or press-fit fittings, threaded connections are not permitted.
Additionally, shutoff valves located behind appliances such as ranges and dryers are now officially recognized as accessible. Plastic vent piping must carry labels in accordance with the manufacturer’s specifications, and UL1738 remains an approved alternative standard. Updates have also been made to the required clearances between direct-vent appliance exhausts and exterior building openings, aimed at reducing the risk of hazardous gases entering buildings and enhancing overall safety during installation.