Process Units
Process Unit Valve Reference

Valves for the LNG Liquefaction Train

Cools natural gas to roughly -162C for storage and transport as liquid. Every wetted valve below the pre-cooling stage is cryogenic-rated, and thermal-cycling durability governs the whole train.

LNGGas Processing

What are the critical valves in a LNG Liquefaction Train?

Main cryogenic heat exchanger isolation (Ball Valves) — Cryogenic ball valves with extended bonnets isolate the coldest section of the train. LNG storage tank inlet/outlet (Gate Valves) — Cryogenic gate valves for tank filling and send-out. Boil-off gas relief (Safety & Relief Valves) — Cryogenic safety relief valves protect against tank and line overpressure from boil-off.

Critical Valve Points

Main cryogenic heat exchanger isolation

Ball Valves

Cryogenic ball valves with extended bonnets isolate the coldest section of the train.

LNG storage tank inlet/outlet

Gate Valves

Cryogenic gate valves for tank filling and send-out.

Boil-off gas relief

Safety & Relief Valves

Cryogenic safety relief valves protect against tank and line overpressure from boil-off.

Unit-Level Valve Strategy

  • Extended-bonnet, cryogenic-rated valves (BS 6364) are mandatory below the pre-cooling stage - standard-bonnet valves cannot maintain stem-packing integrity at cryogenic temperature
  • Boil-off gas (BOG) handling requires valves rated for the same cryogenic range even during upset venting
  • Thermal-cycling fatigue on start-up/shutdown - far more frequent in LNG service than steady continuous plants - drives seat and bellows life

Equipment in this Unit

Fluids in this Unit

Governing Standards

Related process units

Reviewed by Process Engineering, Vajra Industrial SolutionsDiscipline: Valve Service SpecificationLast reviewed: 20 June 2026

Connected Engineering

Sourcing valves for a LNG Liquefaction Train?

Send your unit valve list — we supply the full set (Ball Valves, Gate Valves, Safety & Relief Valves) with certification matched to BS 6364, in one PO.

Engineering references