The tightness of the safety valves has been proven under real conditions at media temperatures below -146 °C on LESER’s own cryogenic test bench. The precise helium leak test is based on the DIN EN 13648-1 standard.

The plant efficiency was supported by the use of pilot-operated safety valves (POSV) in the relevant areas. In contrast to spring-loaded safety valves, they are tight until they respond and thus meet the requirement of a higher operating pressure in relation to the response pressure of the plant. Six POSVs now support the efficiency of LIMUM® technology the liquefaction plant.

The LESER POSV for LNG is based on the proven design for LPG applications - Liquefied Petroleum Gas, which has been in use for many years as a standardized solution. 

For the LNG low temperature range, LESER has further developed the design modularly so that it can be adapted to the respective project requirements. In the plant in Russia, for example, an evaporator was used and the pilot was thermally decoupled from the main valve to ensure a gaseous media state in the pilot. A temperature-resistant PTFE compound for piston sealing in the main valve enables the spring-loaded lip seal to be used at operating temperatures as low as -162 °C. The main valve is equipped with a PTFE compound for the sealing of the piston. The special seat bushing design does not require a soft seal in the wetted inlet area. The controlling pilot valve is available with a low-temperature resistant soft seal in Pop Action and Modulate Action versions for various requirements.

LESER’s project department supported Linde from the first FEED phase to the commissioning of the project. The production segment “Project Assembly” is specially designed for the requirements of projects and offers optimal conditions for customer acceptance.

Why did the customer choose LESER products? 
Linde relies on LESER’s know-how in the cryogenic market, for example in projects with temperatures down to -269 °C for liquid helium applications. The company has been working with LESER in the field of technical gases for many years and knows their services very well. The joint experience in the project management of air separation plants and the complete LNG product range, in particular the modular Cryo-POSV in the Pop Action version, were important for Linde.