Polyethylene piping systems are limited to vapor service not exceeding which pressure?

In the context of polyethylene piping systems designed for vapor service, the maximum allowable pressure is critical for ensuring safety and integrity of the piping. Polyethylene is a flexible, lightweight plastic used in various piping applications, including propane and gas distribution. The material has specific limitations regarding pressure and temperature, beyond which it may fail or compromise the system's safety.

For vapor service, polyethylene piping systems are typically rated for a maximum pressure of 30 psig. This limit is established based on the mechanical properties of the polyethylene material, which can become less effective at containing gas under higher pressure conditions. Exceeding this pressure could lead to physical failure, leaks, or catastrophic events, making adherence to the specified limit crucial.

The other options present higher pressure limits, which are not permissible for polyethylene systems in vapor service as they exceed the material's safe operating parameters. This ensures that the system remains compliant with safety regulations and minimizes risks related to gas containment.