Which ANSI standard must PVC plastic pipe conform to for connecting gas pressure regulator vents?

The correct standard for PVC plastic pipes used in gas applications, specifically for connecting gas pressure regulator vents, is ANSI/UL 651. This standard pertains to the specifications that ensure safety and reliability in the use of PVC pipes in the context of gas utilities. The primary focus of ANSI/UL 651 includes the requirements for materials, manufacturing, and testing to ensure the pipes can withstand the pressures and environmental conditions commonly encountered in gas distribution systems.

By conforming to ANSI/UL 651, PVC pipes demonstrate their capability to effectively handle gas without risking leaks, structural failure, or other safety hazards. This standard is crucial for maintaining the integrity of gas venting systems, which are vital for the safe operation of gas appliances and regulators.

The other standards mentioned may pertain to different types of materials or applications, but they do not specifically address the requirements for PVC pipes in the context of gas pressure regulation systems. Thus, ANSI/UL 651 is the appropriate and necessary standard to ensure that the materials used meet safety and operational criteria specific to gas venting applications.