Requirements on safety valves for use in LNG systems: Proof of functionality under extreme conditions

LESER demonstrates the correct function of its spring-loaded and pilot-controlled safety valves under real low-temperature conditions on a specially designed test bench.

For this new functional test, LESER developed a new test concept consisting of a 1000 l Cryo-Cyl filled with liquid nitrogen at -196 °C / -320 °F. The new test concept is based on the use of a new test system. The test pressures were achieved by superimposing gaseous nitrogen.

After complete cooling to below -162 °C / -260 °F at the inlet, the functional tests were carried out. The safety valves were started up with three consecutive opening cycles at a set pressure of 16 bar, with liquid nitrogen still present.

Even after repeated response, perfect functioning of opening and closing was achieved. This means that there were no functional restrictions due to temperature influences on the functionally important components, such as the spindle and spindle guide. A sign that these temperature conditions have already been taken into account in the development of the design.

This result again proves that LESER safety valves work safely and flawlessly even under difficult operating conditions, as here with a cryogenic medium.

In addition to this extended functional test, LESER has been operating a test bench for safety valves for measuring the tightness with helium under cryogenic conditions on the basis of ISO 13648-1 for quite some time.