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.

Trunnion Ball Valve Features

• Supports the ball and helps reduce seat loading and operating torque.
• Suitable for demanding pipeline and process services when designed for the required pressure class.
• Available for larger pipeline diameters according to the selected design.
• The supported ball can require less torque than comparable floating-ball designs, particularly at larger sizes.
• Provides on/off isolation for compatible process and pipeline services.
• Helps retain the stem within the valve body under pressure.
• Helps provide electrical continuity between valve components where required.
• Can be operated using a gearbox or automated with pneumatic, electric, hydraulic or gas-over-oil systems.

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

Applications

• Oil & Gas
• Natural Gas Transmission
• Petrochemical
• Refineries
• LNG Facilities
• Chemical Processing
• Power Generation
• Mining
• Pipeline Terminals
• Industrial Processes
• Offshore Systems
• High-Pressure Services

Testing & Standards

The standards applicable to a trunnion ball valve depend on its design, pressure rating, materials, end connections and intended service. Relevant requirements may include API 6D, ISO 14313, ASME B16.34, ASME B16.10, API 598 and ISO 5208, as applicable to the selected valve.