What is a trunnion mounted ball valve
A Trunnion Mounted ball valve is a high-performance industrial valve where the ball is securely Trunnion Mounted within the valve body and does not shift under medium pressure. Unlike floating ball valves, the fluid pressure forces on the ball are transferred to bearings instead of the valve seat, reducing seat deformation and ensuring stable sealing. This design offers low torque, long service life, and superior performance in high-pressure, large-diameter systems.
Structural Features of Trunnion Mounted Ball Valves
- Double Valve Seat Design: Enables bidirectional sealing with no flow restrictions.
- Spring Preload Mechanism: Ensures upstream sealing via PTFE-embedded stainless steel valve seats.
- Upper/Lower Bearing Support: Fixes the ball in place, minimizing valve seat workload.
- Robust Construction: Thick valve body with visible upper/lower stems and optional grease injection ports for maintenance.
How Trunnion Mounted Ball Valves Work
The ball rotates 90° to open or close the valve. When closed, the spherical surface blocks fluid flow; when open, the aligned channel allows full passage. The Trunnion Mounted ball design ensures:
- Stable Sealing: Preloaded valve seats maintain tight contact regardless of pressure fluctuations.
- Reduced Wear: Bearings absorb fluid pressure, preventing ball displacement.
Applications of Trunnion Mounted Ball Valves
Trunnion Mounted ball valves excel in high-pressure and corrosive environments, including:
- Oil refining and long-distance pipelines
- Chemical processing and power generation
- Water treatment, HVAC, and environmental systems
- High-temperature steam and gas distribution
Trunnion Mounted Ball Valve vs. Floating Ball Valve: Key Differences
Trunnion vs Floating Ball Valve: Which One is Right for Your Application
| Feature | Floating Ball Valve | Trunnion Mounted Ball Valve |
| Structure | Ball floats; single lower stem connection | Ball Trunnion Mounted via upper/lower stems; movable seats |
| Sealing Mechanism | Medium pressure pushes ball against outlet seat | Spring preload and stem force ensure sealing |
| Pressure Handling | Suitable for low/medium pressure | Ideal for high-pressure systems (up to 42.0Mpa) |
| Durability | Prone to seat wear under high pressure | Long-lasting with minimal deformation |
| Cost & Maintenance | Lower cost, simpler maintenance | Higher initial cost, optimized for harsh conditions |
NSW: Trusted Trunnion Mounted Ball Valve Supplier in China
NSW Valve Manufacturer is a leading manufacturer of API 6D-certified ball valves, including trunnion mounted ball valves, floating ball valves, and bronze API 6d ball valve factory. Our products are widely used in petroleum, natural gas, and industrial pipelines.
Key Specifications:
- Sizes: ½” to 48″ (DN50–DN1200)
- Pressure Rating: Class 150LB–2500LB (1.6Mpa–42.0Mpa)
- Materials: Carbon steel, stainless steel, duplex steel, aluminum bronze
- Standards: API, ANSI, GB, DIN
- Temperature Range: -196°C to +550°C
- Actuation: Manual, pneumatic, electric, or gear-operated
Applications: Oil refining, chemical processing, water supply, power generation, and more.
Post time: Apr-03-2025