LNG

LNG liquefaction plants compress and cool natural gas to -162°C using mixed refrigerant cycles (C3MR, AP-X). Cryogenic ball valves isolate liquefaction exchangers and LNG storage tank feed lines. Extended bonnet designs keep stem packing above 0°C, preventing frost accumulation and packing failure. Austenitic stainless steel (304L/316L) prevents brittle fracture at cryogenic temperatures.

LNG storage tanks use cryogenic valves for fill, withdrawal, and boil-off gas management. Marine loading arms connect LNG carriers to terminal piping via cryogenic DBB isolation valves. Top-entry designs allow in-line maintenance without removing valves from cryogenic service, critical for continuous terminal operations.

LNG import terminals regasify LNG using seawater vaporizers, submerged combustion vaporizers, or ambient air vaporizers. Cryogenic butterfly valves control seawater flow to vaporizer units. After vaporization, the natural gas enters the distribution pipeline through pressure letdown stations using globe control valves.

LNG carriers use cargo handling systems with cryogenic valves for loading, unloading, and tank management. All-welded DBB valves eliminate body joint leaks in marine environments. Valves must withstand ship motion, vibration, and thermal cycling between ambient and cryogenic conditions. IGC Code compliance is mandatory.