At what pressure must LNG/LHG transfer systems be pressure tested?

The correct answer is that LNG/LHG transfer systems must be pressure tested at a level of 1.1 times the Maximum Allowable Working Pressure (MAWP). This practice is grounded in safety and regulatory standards that govern the handling of cryogenic liquids. The rationale behind requiring a test pressure of 1.1 times the MAWP is to provide a margin of safety during the testing process.

This means that the equipment is subjected to conditions slightly above its maximum designed operational pressure to ensure that it can handle operational stresses and potential overpressure scenarios without failure. Such a testing protocol is crucial to verify the integrity and leak-tightness of the system before it is put into service, reducing the risk of accidents or incidents related to pressure failures.

The requirement for a pressure test at this level helps ensure that the materials, joints, and seals can withstand factors such as temperature fluctuations and operational impacts that might occur during actual service. This careful approach reflects industry best practices designed to protect both personnel and the environment from potential hazards associated with the transfer and storage of LNG/LHG.