What is the maximum working pressure for 3/4 inch PVC Schedule 80 pipe?

The correct answer is based on the specifications provided by the American Society for Testing and Materials (ASTM) for PVC Schedule 80 piping. For a standard 3/4-inch PVC Schedule 80 pipe, the maximum working pressure is indeed 320 psi at a temperature of 73°F. This rating indicates the pipe's ability to handle internal pressure without failing, making it suitable for a variety of plumbing applications that require higher pressure resistance compared to Schedule 40 PVC pipe.

When working with PVC piping, it's essential to consider not just the pressure rating but also the temperature, as the maximum operating pressure can decrease with increasing temperatures. The 320 psi rating provides a good balance of strength and durability for applications that involve pressurized liquid transport.

In practical applications, understanding this rating is crucial for ensuring that the selected piping material is appropriate for the intended use, thereby preventing potential failures or leaks in plumbing systems. This knowledge aids plumbing contractors in making informed decisions about materials for both residential and commercial installations.