Pipeline safety has come to the forefront lately because of catastrophic pipeline failures. These failures have occurred primarily on older pipelines because quality requirements for new pipeline construction are very stringent. Valves for pipeline service are also scrutinized very closely. While all pipeline valves are hydrostatically tested at the factory, usually in accordance with API 6D, additional tests are almost always performed. The most common extreme test for pipeline Valves is a long duration shell test, which is carefully monitored by a recording device tracking the pressure and the temperature of the valve as it is tested.

During these enhanced duration shell integrity tests, the pressure on the valve must be maintained, or the pressure drop must coincide with a proportional drop in temperature to avoid Valves failure. It is not uncommon for test durations to run several hours long.