What is the minimum test pressure for a 0.5 psi gas system?

The minimum test pressure for a 0.5 psi gas system is typically established based on codes and standards governing gas systems. In this case, the correct pressure of 3 psi is determined based on the requirement that the testing must be conducted at a pressure that is typically six times the normal operating pressure. This is to ensure that the system is adequately leak-tested and functioning properly under conditions that exceed normal operations.

Testing at 3 psi provides a sufficient safety margin to eliminate any potential weaknesses or leaks in the system that might not be detected at lower pressures. It is important to conduct these tests as per the guidelines set by the National Fuel Gas Code or other applicable regulations, which specify that the testing parameters be designed for safety and reliability.

In contrast, the other pressures do not meet the necessary criteria for thorough testing of a 0.5 psi system, making 3 psi the correct minimum for ensuring compliance and safety in gas system installations.