CRYOGENIC VALVES
Figure 1. Extended bonnet cryogenic ball valve design: The elongated stem housing keeps the packing away from the – 196 ° C fluid, preventing embrittlement, minimizing frost build-up, and ensuring reliable operation in LNG and liquid hydrogen service
petrochemical facilities. Cryogenic fire testing subjects valves to rapid temperature excursions from – 196 ° C to over 750 ° C, evaluating whether internal components maintain structural integrity( Argus, 2023; Habonim, 2022). The combination of brittle fracture risks at low temperature and oxidation at high temperature creates a dual extreme design envelope.
Integrating these requirements with cryogenic test protocols creates a challenge: maintaining tight sealing at – 196 ° C while guaranteeing containment under high-temperature fire tests. Manufacturers increasingly adopt lowemission stem packings, double-sealing arrangements, and surface-engineered alloys to comply with these converging standards. For hydrogen service, some designs add secondary containment cavities with purge ports, ensuring that even if a primary seal fails, fugitive emissions can be captured and vented safely( Mills & Langner, 2023).
Extended bonnet designs: Ensuring safe operation below – 196 ° C
One hallmark of cryogenic valves is the extended bonnet, a design feature that
Table 1. Typical extended bonnet dimensions for cryogenic ball valves; Based on API 6D, BS 6364, and recent engineering case studies
Valve Size( DN) |
Pressure Class |
Face-to-Face |
Bonnet Tube OD x wall( mm) |
Bonnet Length( mm) |
Notes / Uses |
Citations |
25 – 50 150 |
ASME B16.10 short |
60 – 76 × 3 – 4 200 – 260 Skids, analyzers, LH2 vents |
( Hartmann Valves, 2015; Emerson, 2017) |
80 – 100 150 / 300 B16.10 short 76 – 89 × 4 – 5 250 – 320 LNG / LPG lines, BOG lines
( Sim, 2021; Garcia & Martinez, 2025)
150 150 / 300 B16.10 long |
95 – 114 × 5 – 6 |
300 – 380 Jetty lines, ship manifolds |
( API, 2021; Velázquez et al., 2022) |
200 300 B16.10 long |
114 – 127 × 6 – 7 |
350 – 450 LNG send-out / regas |
( Abdullah et al., 2017; Emerson, 2017) |
250 – 300 300 / 600 B16.10 long |
127 – 141 × 6 – 8 |
400 – 520 Large transfer lines |
( Garcia & Martinez, 2025; Ivancu & Popescu, 2023) |
350 – 400 600 B16.10 long |
141 – 168 × 8 – 10 |
450 – 600 Trunklines, cold boxes |
( Velázquez et al., 2022; Mills & Langner, 2023) |
500 – 600 600 / 900 B16.10 long |
168 – 219 × 10 – 12 |
520 – 700 Main LNG / LH2 headers |
( Peng et al., 2021; Argus, 2023) |
750 – 900 600 / 900 Project-specific |
219 – 273 × 12 – 14 |
650 – 850 Export lines / FLNG |
( Morgan, 2021; Singh et al., 2022) |
26 Valve World November 2025 www. valve-world. net