Which step best describes proper preparation before performing a tightness test on piping?

Which step best describes proper preparation before performing a tightness test on piping?

• A. Shut off and vent the product side and isolate the section being tested
• B. Leave all valves open and vent the system
• C. Test with no isolation or venting
• D. Only test during high ambient temperatures

Answer: (C)

Focusing on how the piping will perform in real service is the key. The best preparation for a tightness test is to run the test with the piping in its installed, connected state—without isolating sections or venting. This approach exposes any leaks along the actual pressure paths that would occur during normal operation, providing a true measure of tightness. Isolating parts or venting can change where leaks show up, mask potential leak paths, or alter pressure conditions, leading to an inaccurate assessment. Testing under these conditions—keeping the system as it would be in use—gives the most reliable indication of whether the piping is tight.

Focusing on how the piping will perform in real service is the key. The best preparation for a tightness test is to run the test with the piping in its installed, connected state—without isolating sections or venting. This approach exposes any leaks along the actual pressure paths that would occur during normal operation, providing a true measure of tightness. Isolating parts or venting can change where leaks show up, mask potential leak paths, or alter pressure conditions, leading to an inaccurate assessment. Testing under these conditions—keeping the system as it would be in use—gives the most reliable indication of whether the piping is tight.