High Performance Cryogenic Valve Manufacturer in Germany

Cryogenic valves are designed for the isolation and control of fluids stored or transported at extremely low temperatures. Services involving LNG, liquid nitrogen, liquid oxygen, liquid argon and other liquefied gases require valve construction that can maintain mechanical strength, sealing performance and reliable operation during repeated thermal cycling.

Valve Design for Cryogenic Fluid Service:

Cryogenic valve design therefore focuses on:

• Maintaining material toughness at low temperature
• Protecting stem packing from direct cryogenic exposure
• Controlling thermal contraction
• Maintaining seat sealing during temperature cycling
• Preventing trapped-liquid overpressure
• Limiting fugitive leakage around the stem
• Providing reliable operation after cool-down

The exact design depends on the cryogenic fluid, pressure, valve type and minimum operating temperature.

Extended Bonnet and Stem Construction:

• An extended bonnet increases the distance between the cryogenic process fluid and the stem packing or actuator interface. This creates a thermal gradient that helps keep the packing assembly at a temperature at which it can maintain effective sealing.
• The extension length depends on valve size, fluid temperature, insulation arrangement and installation orientation.
• Extended stem construction also provides clearance above piping insulation and facilitates operation or actuator mounting without disturbing the insulated section of the line.
• Cryogenic globe, gate and ball valves can therefore use extended bonnet or stem arrangements according to their individual design.

Cryogenic Valve Configurations

• Cryogenic Ball Valve: Quarter turn isolation with floating or trunnion design.
• Cryogenic Gate Valve: Full bore isolation for unrestricted flow.
• Cryogenic Globe Valve: Suitable for isolation and throttling.
• Cryogenic Check Valve: Prevents reverse flow automatically.
• Other Options: Long stem, short stem, jacketed and actuated configurations.

Low Temperature Materials and Seals:

Cryogenic valve body and pressure containing materials must retain adequate toughness at the specified minimum design temperature.

Common materials may include:

• ASTM A352 LCB
• ASTM A352 LCC
• ASTM A351 CF8
• ASTM A351 CF8M
• ASTM A351 CF3
• ASTM A351 CF3M
• SS304
• SS304L
• SS316
• SS316L

Austenitic stainless steels are widely used for very-low-temperature service because they retain toughness at cryogenic temperatures.

Seat and sealing materials can include:

• PCTFE
• PTFE or modified PTFE for suitable temperature ranges
• Reinforced polymer seats
• Metal seats
• Graphite packing
• Low emission packing arrangements

Material compatibility must be verified for the actual fluid, temperature and pressure.

Cavity Pressure Relief and Thermal Stability

Cryogenic liquids trapped in the valve cavity can expand during warming and create excessive pressure.

• Pressure Relief: Self relieving seats, relief holes or venting arrangements.
• Thermal Stability: Proper material selection and clearances compensate for contraction of the body, stem and seats.
• Performance: Maintains sealing and operating torque throughout temperature changes.

Cryogenic Testing and Applicable Standards:

Cryogenic valves should be tested according to the valve type, project specification and required minimum design temperature.

Applicable requirements may include:

• BS 6364 for cryogenic valve requirements where specified
• ISO 28921-1 for isolation valve used in low temperature applications where applicable
• ASME B16.34 or EN 12516 for pressure design according to valve construction
• EN 12266-1 / API 598 for pressure testing where applicable
• API 6D for applicable pipeline ball/check/gate valve designs
• EN 10204 3.1 / 3.2 material inspection documentation where specified
• PED 2014/68/EU conformity for applicable European pressure equipment

Actuation and Installation Requirements:

Cryogenic valves can be manually operated or fitted with pneumatic or electric actuators.

Actuator sizing should account for:

• Increased operating torque at low temperature
• Seat friction
• Differential pressure
• Packing load
• Required opening and closing time
• Fail safe position
• Available air or electrical supply

Valve orientation is also important. Extended bonnet designs are normally installed according to the manufacturer’s specified orientation so that the packing remains sufficiently separated from the cryogenic fluid.

LNG and Industrial Gas Applications:

Cryogenic valves are used throughout systems handling liquefied gases and very-low-temperature fluids.

Typical applications include:

• LNG storage and transfer
• LNG loading and unloading systems
• Liquefaction and regasification plants
• Liquid nitrogen systems
• Liquid oxygen service
• Liquid argon systems
• Industrial gas production
• Cryogenic storage tanks
• Vaporizers
• Gas separation facilities
• Marine LNG systems
• Low temperature process piping

Valve selection for oxygen service requires additional attention to material compatibility, cleanliness and contamination control. LNG and other hydrocarbon applications may also require fire safe design, fugitive emission control and project specific testing.