A trunnion-mounted ball valve is a valve design in which the ball is fixed by trunnions (support shafts). Its core structure consists of a valve body, a ball, trunnion supports, a valve seat, and an actuator. Unlike traditional floating ball valves, the ball in an imported trunnion-mounted ball valve is fixed by upper and lower trunnions and rotates only around its axis to achieve opening and closing. This design significantly reduces operating torque and improves sealing reliability under high-pressure conditions.
What are the components of a trunnion ball valve?
A trunnion ball valve typically consists of a valve body, ball, seat, stem, and actuator. The ball is fixed in place by bearings on both sides. The stem is connected to the ball, and rotating the stem controls the ball's rotation, thus opening and closing the valve. Because the ball is firmly supported, smooth operation and reliable sealing are ensured even under high pressure differentials or large diameters.
Structural Features:
Fixed Ball Design: The trunnion support structure keeps the ball stable under high pressure, reducing friction and wear with the seat and extending valve life.
Bidirectional Sealing Capability: Spring-loaded seat or metal seal structure ensures leak-proof sealing in both low-pressure and high-pressure systems, and allows for bidirectional pressure resistance.
Low Operating Torque: The trunnion design reduces the torque required to open and close the valve, allowing for smaller actuators and lower operating costs.
Anti-Flyout Stem Structure: The stem is fixed by a special design (such as an anti-flyout structure) to prevent it from popping out due to sudden pressure changes, improving safety.
High flow rate design: The diameter of the spherical through-hole matches the inner diameter of the pipe, reducing pressure drop and making it suitable for high flow rate conditions.
Performance Advantages
High Pressure and High Temperature Resistance: Imported trunnion-type ball valves can withstand pressures from 6000 psig (413 bar) to 10000 psig (689 bar), with an operating temperature range of -17℃ to 232℃, and some low-temperature models down to -50℃.
Strong Corrosion Resistance: The valve body, ball, and stem are typically made of corrosion-resistant materials such as F316 stainless steel, suitable for corrosive media environments such as chemical and petroleum industries.
Excellent Sealing Performance: Utilizing high-performance sealing materials such as PTFE and RPTFE, combined with precision machining processes, ensures long-term sealing reliability and reduces the risk of leakage.
Long Service Life and Low Maintenance: The fixed ball and trunnion support structure reduce wear, and the self-lubricating seat design lowers maintenance frequency and costs.
trunnion ball valve in stock
