Trunnion Ball Valve

African Valve, a Trunnion Ball Valve Supplier in Nigeria, supplies trunnion-mounted ball valves for applications where reliable shut-off is required at larger sizes and higher pressures. Unlike a floating ball valve, a trunnion-mounted ball is supported by upper and lower trunnions within the valve body. This arrangement helps reduce the load placed on the seats and can lower operating torque, particularly as valve size and pressure rating increase.

Trunnion ball valves are commonly selected for oil and gas pipelines, natural gas transmission, refineries, petrochemical plants, gas processing facilities and other industrial process systems. The final valve configuration, materials and pressure rating are selected according to the operating conditions and project requirements.

Engineering Design & Operation

A trunnion ball valve operates through a 90° rotation of a spherical ball. When the bore through the ball is aligned with the pipeline, the valve is open and fluid can pass through. Rotating the ball by 90 degrees moves the solid section across the flow path and stops the flow.

In a trunnion-mounted design, the ball is supported by upper and lower trunnions. The fixed support limits ball movement and reduces the load transferred to the valve seats. This arrangement can be particularly beneficial for larger sizes and higher-pressure classes, where a floating ball design may require greater operating torque.

Technical Specifications

Materials & Components

• Body: ASTM A216 WCB, ASTM A352 LCB, ASTM A105, ASTM A350 LF2, ASTM A182 F304, ASTM A182 F316, Duplex and Super Duplex Stainless Steel
• Ball: Carbon steel, stainless steel, Duplex and Super Duplex materials, depending on service
• Stem: AISI 316, AISI 410, 17-4PH and Duplex Stainless Steel
• Trunnion: Carbon Steel, Stainless Steel, Alloy Steel or Duplex, depending on design
• Seat: PTFE, RPTFE, PEEK, nylon or metal-to-metal seat options
• Seat Springs: Stainless Steel, Inconel or alloy steel