To determine the gasket tightness at maximum design temperature.
1. Increase test temperature to maximum design temperature at a rate of 100°C (212°F) per hour.
2. Increase test pressure up to the rated pressure at maximum design temperature and stabilize this condition for 1 hour (isolate test fluid from test rig).
3. Decrease test temperature until ambient temperature.
4. Increase test temperature to maximum design temperature at a rate of 100°C (212°F) per hour and stabilize the reached test situation for 1 hour.
5. Repeat step 3.
6. Repeat step 4 and step 5 for 2 times and record the pressure drop during the final cycle.
The gasket was compressed with a gasket stress of 811.7 MPa. After heating up to 400°C the specimen was pressurized with 34.7 bar helium (in accordance to ASME B16.5-2017 - PT-Rating for Group 1.1 Materials), no load compensation of the internal pressure is done.
The maximum pressure loss during the final cycle is 1 bar (14.5 psi).
During the thermal cycles in the leakage test at 400°C, only a small pressure drop could be measured:
During the last thermal cycle, the pressure loss was less than 0.2 bar. The DeltaV-Seal has passed the Shell requirement of a pressure drop of less than 1 bar.