What must plastic pipe, tubing, and fittings used to supply fuel gas be marked with?

Plastic pipe, tubing, and fittings that are intended to supply fuel gas must be clearly marked with "Gas" along with the appropriate ASTM standard, which is ASTM D 2513. This specific standard outlines the requirements for plastic piping systems used for gas distribution, ensuring that the materials are suitable for the task at hand. The marking is essential for safety and regulatory compliance, as it helps identify the pipe’s intended use and indicates that it meets the necessary performance standards for fuel gas service. This labeling not only aids in proper installation and maintenance but also assists inspectors and workers in ensuring that the right materials are used in gas systems, promoting safe practices in fuel gas applications.