Liquefied Natural Gas (LNG) Processing and Transportation is a very demanding industry in which operational excellence and probable catastrophic failure is heavily dependent upon critical components. Trunnion mounted ball valve is one such critical component, which contributes to success by providing incomparable performance in extremely demanding cryogenic conditions.

What are Trunnion Mounted Ball Valves?

Compared to conventional floating ball valves, trunnion mounted ball valves are made with a unique mechanical arrangement. In a trunnion mounted ball valve the key differentiator is the ball’s support system.

  • The top and bottom of the valve are fixed trunnions or support pins.
  • Additional bearings are positioned on the side to enhance stability.
  • This design facilitates better sealing and reduced operating torque.

Cryogenic Limitations in LNG Application

For valve technologies LNG applications encounter distinct challenges:

  • Extremely Chilly Temperatures ( around -260 degree F or – 162 degree F)
  • High pressure work environment
  • Critical parameters for zero leakage
  • Requirement for consistent thermal cycling performance

Fundamental Performance Advantages of Trunnion Mounted Ball Valves in LNG

  • Robust and Superior Sealing Mechanism

The trunnion design provides numerous sealing points like:

  • Primary Seat Seals
  • Secondary Seat Seals
  • Stem Seals

This multi-layered technique not only guarantees superior leak prevention, but also meets the most stringent API 6D and ISO14313 standards for zero leakage classifications.

 

  • Mechanical Stability in Cryogenic Conditions

Unlike floating ball valves, trunnion mounted designs:

  • Maintain constant pressure ratings even during extreme temperatures
  • Limits ball and seal deformation
  • Provides predictable mechanism reaction during thermal cycling

 

  • Lesser Operating Torque

The working torque is significantly decreased by the trunnion support mechanism by:

  • Removing direct ball-to-seat friction
  • Distributing mechanical stress among several support points
  • Facilitating better actuator selection and lower energy consumption

 Important Considerations for Material Selection for LNG Service

Cryogenic valve performance depends upon the appropriate selection of materials:

Body Materials: Ideal materials include low temperature carbon steel or austenitic stainless steel

Ball and Stem: Forged stainless steel with special cryogenic treatments

Seat Rings: Metal seated designs or sophisticated polymers

Seals: Unique cryogenic grade elastomers or metal seals

Design Features for Increased Dependability

Blow-out Proof Stem: Guards against potentially dangerous stem ejection by maintaining system integration under extreme pressure conditions

Anti-static Design: Grounding connections are integrated into the anti-static design to prevent the accumulation of static electricity, which is crucial in environments of explosive gases.

Fire Safe Construction: Meets stringent fire safety testing requirements set forth by ISO10497 and API 607

Maintenance and Operational Considerations

The following requirements are absolutely essential for the successful implementation of trunnion mounted ball valves in LNG Services:

  • Regular Inspection Duration
  • Appropriate Installation Technique and Procedures
  • Understanding specific operational considerations
  • Compliance with manufacturer-recommended maintenance protocols

FAQs

Q1. What standards govern trunnion ball valves in LNG applications?

Critical standards include:

  • API 6D: Pipeline and Piping Valves
  • ISO14313: Petroleum and Natural Gas Industries-Pipe Lines
  • API607-Fire Test for Soft Seated Quarter-Turn Valves
  • ISO10497-Testing of Valves-Fire-type Testing Requirements

Q2. In what way do trunnion ball valves prevent leakage?

Trunnion ball valves are able to prevent leaks due to:

  • Primary seat seals
  • Secondary sealing for seats
  • Seals on stems
  • Blow-out proof stem design
  • Precision tolerances in manufacturing
  • Multiple sealing points

Q3.How are trunnion ball valves tested for LNG services?

Comprehensive testing includes: 

  • Testing of cryogenic temperature cycles
  • Verification of the pressure ratings
  • Leakage rate testing
  • Analysis of mechanical load and deformation
  • Tests for fire-safety certifications

Q4. How are the cost parameters of trunnion ball valves in LNG services?

Although the initial costs of trunnion mounted ball valves are higher, in the longer run they provide:

  • Lower cost cycles
  • Reduced maintenance costs
  • Enhance operational dependability
  • Longer lifespan in vital applications

Q5. What safety features do trunnion ball valves in LNG services have?

Important safety features include:

  • Anti-static design
  • Fire-safe construction
  • Stem that is blow-out proof
  • Multiple sealing systems
  • Corrosion resistant materials

Conclusion

Trunnion mounted ball valves are an advanced LNG application solution that provides incomparable performance in the most excruciating cryogenic settings. Their sophisticated design, exceptional sealing capabilities, and tough mechanical properties make them an integral and indispensible in contemporary LNG infrastructure. By fusing innovative engineering, carefully chosen materials, and meticulous design considerations these valves guarantee safe, efficient, and dependable LNG processing and transportation.

STEELSTRONG VALVES specializes in a broad spectrum of valve manufacturing that includes superior Design and Engineering, premium Raw Material Procurement, Precision Production, meticulous valve assembly processes, rigorous quality control, and performance verification. STEELSTRONG VALVES manufacture a wide range of valves like Globe Valves, Check Valves, Ball Valves, Gate Vales, and Cryogenic Valves that meet international standards. Their products are compliant with technical specifications from ASME-ASNI, API, and British Standards (BS). SteelStrong is your trusted valve partner.