Cryogenic Valves Supply and Service

Cryogenic valves are a specialized class of valves designed to operate reliably and safely at extremely low temperatures, typically defined as below -100°C (-148°F) and extending down to near absolute zero (-273.15°C or -459.67°F).

These valves are critical for industries that handle cryogens such as:

• LNG (Liquefied Natural Gas)
• Liquid oxygen (LOX)
• Liquid nitrogen (LN2)
• Liquid hydrogen (LH2)
• Liquid Helium
• LPG (Liquefied Petroleum Gas)

When it comes to safely handling cryogens, compromise isn’t an option. Williams Valve delivers reliable cryogenic valves engineered to ensure integrity at extremely low temperatures. Our valves are thoroughly tested to meet the highest industry standards for critical cryogenic service.

Operational Challenges of Cryogenic Service for Valves

• Material Brittleness: Many common engineering materials become brittle and lose their ductility and toughness at cryogenic temperatures, making them susceptible to fracture.
• Thermal Contraction and Expansion: Different materials contract and expand at different rates as temperatures change. This differential thermal contraction can lead to leakage, loss of sealing integrity, jamming of internal components, or even structural failure if not accounted for in the design.
• Sealing Challenges: Conventional elastomers and soft packing materials become rigid and lose their sealing capabilities at cryogenic temperatures. Achieving a tight, leak-proof seal is one of the most significant design challenges.
• Heat Leak: Any heat transferred from the ambient environment into the cryogenic fluid can cause the liquid to vaporize and build pressure rapidly. Valves must be designed to minimize heat leak to prevent product loss, maintain desired temperature, and prevent overpressure.
• Ice Formation: Moisture from the atmosphere can freeze on external surfaces, potentially interfering with valve operation or damaging components. Internal ice formation from impurities in the fluid can also cause issues.
• Safety Hazards: Cryogenic fluids can pose significant hazards. Many cryogens (LNG, LH2, LOX) are highly flammable or can support combustion, leading to fire and explosion risks if leaked and mixed with air. In addition, rapid vaporization can displace oxygen in confined spaces, potentially leading to asphyxiation. This is why preventing leakage of hazardous cryogens to the atmosphere is a critical environmental and safety concern and is regulated by standards like ISO 15848 and API 641.

Our Cryogenic Valve Design – Gate and Globe

Cryogenic valves incorporate specialized design elements to meet the operational challenges of this severe service. Extended bonnets or columns are the most distinguishing feature. The valve stem is significantly elongated to create a gas column between the cold fluid and the stem packing/gland.

This design creates a temperature gradient, allowing the packing to operate at a higher, more ambient temperature so that the conventional sealing materials can retain their flexibility and sealing properties. It also minimizes heat transfer from the ambient environment to the cryogenic fluid, and prevents ice formation around the stem packing that could seize the valve or damage the seal.

For gate valves, pressure relief features can be incorporated such as self-relieving seats or small relief holes in the upstream side of the gate. This prevents dangerous pressure buildup in the trapped liquid that can occur due to thermal expansion as the liquid warms and vaporizes in the closed body cavity.

Specialized Materials for Cryogenic Valves

Austenitic stainless steels (304, 304L, 316, 316L, 321) are commonly used due to their excellent toughness, ductility, and corrosion resistance at cryogenic temperatures. Nickel alloys and certain aluminum alloys may be used where higher strength or specific chemical compatibility is needed.

For sealing materials, traditional elastomers are avoided. Instead, modified PTFE , PCTFE, and reinforced graphite work best for soft seats, packing, and gaskets due to their flexibility and low-temperature performance. Metal-to-metal seating is also used for tight shut-off and fire-safe designs.

Forged Steel Cryogenic Valve Specifications

Our cryogenic valves are available in gate and globe configurations. Valves are designed with an extended bonnet for use in cold services to -320 degrees F (-196 degrees C). Construction includes:

• Full Port or Standard Port
• Two Piece Self-Aligning Packing Gland
• Bolted Bonnet with Spiral-Wound Gasket, Threaded and Seal Welded Bonnet, or Threaded and Pressure Seal Bonnet
• Integral Backseat
• Pressure Relief Hole on Seat – Gate Valves
• Socket Weld Ends or Screwed Ends (NPT)
• Special Extension Ends (available on request)
• Soft Seats – Globe Valves (available on request)
• PTFE Stem Packing (available on request)
• Special Low Temperature Testing (available on request)
• Outside Screw and Yoke (OS&Y)

Valves are available in two bonnet designs:

Bolted Bonnet

1. Male-Female Joint
2. Spiral Wound Gasket
3. Made in F304L/Graphite
4. Ring Joint Gasket available on request

Welded Bonnet

• Threaded and Seal Welded Joint
• Full Penetration Welded Joint available on request

Standards and Testing for Cryogenic Valves

Due to their criticality, cryogenic valves must adhere to very rigorous industry standards. These may include:

• BS 6364 – Specification for Valves for Cryogenic Service (Key standard defining design, manufacturing, inspection, and testing requirements)
• API 598 – Valve Inspection and Testing
• API 6D – Pipeline Valves (for valves in cryogenic pipeline service)
• ASME B16.34 – Valves—Flanged, Threaded, and Welding End
• ISO 15848-1 – Industrial Valves—Measurement, Test And Qualification Procedures For Fugitive Emissions
• API 607/ISO 10497 – Fire Test for Soft-Seated Quarter-Turn Valves
• ASME B16.11 – Forged Fittings, Socket-Welding and Threaded (for Socket Weld Ends)
• ASME B1.20.1 9 – Pipe Threads, General Purpose (for Screwed Ends)
• End-User Specifications (beyond general standards)

Your Trusted Source for Industrial Cryogenic Valves

At Williams Valve, we deliver precisely engineered valves built with specialized materials for extreme low-temperature service. Ensure safety and reliability in your critical cryogenic applications—contact us today to learn more.