The Characteristics of Trunnion Mounted Valve

The Trunnion Mounted Valve is a type of ball valve designed specifically for high-pressure applications, large-diameter pipelines, and systems that require consistent, secure flow control. This valve design differs significantly from floating ball valves due to its ball support system.

1. Fixed Ball Mechanism

The most defining feature of the trunnion mounted valve is its fixed or supported ball. The ball is held in place by two trunnions — one at the top and one at the bottom — which act as mechanical anchors. These trunnions allow the ball to rotate on a fixed axis without shifting along the pipeline, thereby maintaining stability during operation. This feature becomes especially important under high-pressure conditions, as the load from the flow is absorbed by the trunnion structure instead of transferring to the seats.

2. Reduced Operating Torque

Because the ball does not move axially, the operating torque required to turn the ball is significantly reduced. This allows the valve to be actuated with smaller, more efficient gear or motorized operators. Lower torque also enhances longevity, as wear on valve components is minimized.

3. Improved Sealing Performance

Trunnion mounted valves often use a dual-seat design with spring-loaded or pressure-energized seats. These seats maintain contact with the ball to ensure sealing even if pressure drops or fluctuates. In many designs, the seats can move slightly to adapt to changes in pressure, helping maintain a bubble-tight seal.

4. High Integrity and Versatility

These valves are widely used in oil and gas pipelines, petrochemical plants, and other high-stakes applications where performance and safety are paramount. Fire-safe designs, anti-static devices, and emergency sealant injection fittings are common optional features for trunnion valves.

The Tubing Floating Ball Check Valve is a compact, self-acting valve used predominantly in applications such as downhole operations, chemical injection systems, or any service where backflow prevention within tubing or small-diameter piping is necessary. Its design emphasizes compact dimensions and reliable check action.

1. Valve Body Dimensions

The body of a tubing floating ball check valve is usually cylindrical to match the tubing profile it is integrated into. Standard outer diameters (OD) align with commonly used tubing sizes, such as 1/4”, 3/8”, 1/2”, and up to 2” for industrial uses. The compact length of the valve body helps in conserving space within confined systems.

2. Internal Ball Size and Seat

The ball inside the valve must be precisely machined to ensure it seats properly when reverse flow occurs. Typically made of stainless steel or other corrosion-resistant materials, the ball diameter is slightly smaller than the internal bore, allowing free movement during forward flow and a secure seal against the seat during backflow. Ball diameters are commonly in the range of 4 mm to 25 mm depending on the overall valve size.

3. Bore and Flow Passage

The bore of the valve is aligned with the tubing to ensure minimal pressure loss and turbulence. The floating ball mechanism ensures that the ball moves freely with the flow until reverse pressure causes it to seat. The bore diameter is usually matched with the tubing inner diameter (ID) to ensure uniform flow, with careful consideration given to maintain flow rates and reduce pressure drop.

4. End Connections and Sealing

Depending on application requirements, the ends of the tubing floating ball check valve may be threaded, welded, or compression-type fittings. Dimensions of these ends are standardized for compatibility with common tubing connectors. Sealing elements such as O-rings or Teflon rings are incorporated into the body to prevent leaks around the ball or seat area.

5. Pressure Ratings and Wall Thickness

The wall thickness of the valve body must comply with the pressure class it is designed for. For example, valves used in oilfield environments may be rated up to 10,000 psi, requiring thicker bodies and appropriately sized balls and seats. These dimensions are critical for safe operation and long-term reliability.