Cryogenic/High-Temperature Trunnion Mounted Ball Valves

In extreme working conditions such as liquefied natural gas (LNG), cryogenic chemical engineering, high-temperature refining and chemical processing, and energy transmission, valves are not only fluid control components, but also key nodes ensuring system safety and long-term stable operation. Cryogenic/High-Temperature Trunnion Mounted Ball Valves have emerged as a mature solution widely adopted in such high-demand scenarios.

Combined with the structure of industrial-grade trunnion mounted ball valves shown in the photos, this article analyzes their technical advantages under extreme temperature conditions from multiple dimensions, including design principles, material selection, sealing technology, and application value.

I. Why Trunnion Mounted Structure Is Indispensable for Extreme Temperature Conditions?

Different from floating ball valves, trunnion mounted ball valves support the ball via upper and lower trunnions, maintaining the ball in a stable position even under high pressure, high temperature, or ultra-low temperature conditions:

• Pipeline pressure does not directly cause ball displacement

• Valve seats only perform the sealing function, reducing wear

• Lower operating torque, ideal for electric or pneumatic actuators

Under cryogenic (e.g., -196℃ for LNG) or high-temperature (>400℃) conditions, materials exhibit significant thermal expansion and contraction. Structural stability becomes a decisive factor for valve service life, where the trunnion mounted structure holds inherent advantages.

II. Core Design Differences Between Cryogenic and High-Temperature Conditions

1. Key Technical Points of Cryogenic Trunnion Mounted Ball Valves

In cryogenic medium environments, valves must focus on solving the following problems:

• Low-temperature toughness of materials: Stainless steel (e.g., ASTM A351 CF8M / CF3M) is commonly selected to prevent brittle fracture at extremely low temperatures

• Extended bonnet design: Avoids cold conduction to the packing area, preventing packing freezing or failure

• Cryogenic-specific sealing materials: PTFE, modified PTFE, or metal-soft seal composite structures

• Bidirectional sealing and pressure relief design: Prevents abnormal pressure buildup in the valve cavity caused by temperature changes of the medium

These design features enable cryogenic trunnion mounted ball valves to deliver higher reliability in LNG receiving terminals, liquefaction units, and cryogenic storage and transportation systems.

2. Design Focus of High-Temperature Trunnion Mounted Ball Valves

In high-temperature and high-pressure medium environments, the main challenges for valves lie in sealing stability and structural strength:

• Metal-to-metal sealing structure: Resistant to high temperature and erosion

• Application of high-temperature alloy materials: Such as forged steel grades including A105, F11, F22

• Thermal deformation resistance design: Optimized valve body and seat structure to reduce thermal stress concentration

• Anti-seizure and anti-galling treatment: Ensures smooth opening and closing operation

This structure extends the service life of trunnion mounted ball valves in oil refining, petrochemical cracking, and high-temperature heat transfer oil systems.

III. Nominal Size and Pressure Rating

Cryogenic/High-Temperature Trunnion Mounted Ball Valves are typically suitable for medium-to-large diameter, high-pressure pipeline systems:

• Nominal Diameter (NPS / DN): 1/2”~48” (DN15~DN1200)

• Pressure Rating: 150LB~2500LB (PN20~PN420)

IV. Design and Testing Standards

Valve design and manufacturing usually comply with the following international standards:

• Design Standard: ASME B16.34

• Face-to-Face Dimensions: ASME B16.10 / API 6D

• Flange Connection: ASME B16.5 / ASME B16.47

• Pressure Testing: API 598 / API 6D

• Fire-Safe Design: API 607 / API 6FA

• Cryogenic Testing (if applicable): BS 6364 / ISO 28921

V. Sealing and Safety Advantages of Trunnion Mounted Ball Valves in Extreme Conditions

Whether under cryogenic or high-temperature conditions, trunnion mounted ball valves are usually equipped with the following safety and sealing designs:

• Double seat structure (Double Piston Effect / Single Piston Effect)

• Automatic cavity pressure relief function

• Fire-safe structure design

• Anti-static device

VI. Typical Application Industries and Engineering Value

Cryogenic/High-Temperature Trunnion Mounted Ball Valves are widely used in:

• LNG liquefaction, receiving, and regasification systems

• Petrochemical and refining units

• High-temperature steam and heat transfer oil systems

• Energy transmission and long-distance pipeline projects

VII. Conclusion: Trunnion Mounted Ball Valves Are More Than Valves—They Are Part of System Safety

For extreme temperature conditions, valve selection is no longer just a matter of specification matching, but a comprehensive consideration of materials science, structural mechanics, and sealing technology. With their mature trunnion mounted structure and application-specific designs, Cryogenic/High-Temperature Trunnion Mounted Ball Valves have become irreplaceable core control components in high-demand industrial systems.