According to the American National Standard for Public Spas, what is the required pressure test for circulation system piping?

The correct answer is based on the specified requirement outlined in the American National Standard for Public Spas, which dictates that circulation system piping must undergo a pressure test. This test is conducted at a minimum pressure of 25 lbs/psi to ensure the integrity and safety of the piping system. The purpose of performing this pressure test is to identify any potential leaks or weaknesses in the piping that could result in failures during operation. By adhering to the standard, contractors help guarantee that the spa's circulation system will be reliable and safe for public use.

The other options reflect pressures that are lower than the required minimum and would not adequately verify the robustness of the piping under operational conditions, potentially compromising the safety and effectiveness of the spa's circulation system.