The minimum test pressure for gas piping expressed as an equivalent psi is which of the following?

• A. 1 psi
• B. 2 psi
• C. 3 pounds per square inch
• D. 4 psi

Answer: (C)

Testing gas piping is about verifying the system can hold pressure without leaking and that joints and fittings are sound. The standard specifies a minimum test pressure that must be met, expressed in psi. The lowest acceptable equivalent pressure is 3 psi, so the minimum test pressure to use is 3 psi. Lower values wouldn’t reliably reveal leaks, while higher pressures can be used if the design requires it, but 3 psi is the floor. In cases where the code provides the test pressure in another unit (like inches of water column), it’s just converted to psi to compare with this minimum.