What action should be taken if the seal on a pressure relief valve is broken?

Answer: B — Remove the valve from service until reset and sealed

When the seal on a pressure relief valve is broken, it indicates that the valve has been activated and may not function properly or may have been compromised. Therefore, it is crucial to remove the valve from service until it can be reset and resealed. This action ensures that the valve is operating correctly and safely, as a pressure relief valve is designed to protect systems from pressure build-up. Continuing to use a valve with a broken seal could lead to dangerous situations, including equipment failure or accidents, due to the potential for overpressure conditions that the valve is supposed to mitigate. By removing the valve from service, maintenance personnel can inspect and test it to ensure it is functioning as intended before placing it back into active service, thus maintaining safety and integrity in CNG operations.