A trunnion-type ball valve mainly consists of a valve body, a ball, a trunnion, and an actuator. Its working principle is to control the flow and interruption of fluid flow by rotating the ball. When the ball rotates to align with the valve body passage, fluid flows smoothly; when the ball rotates perpendicular to the valve body passage, the fluid is blocked. This simple and efficient working principle makes trunnion-type ball valves perform excellently in a variety of applications.
A trunnion-type ball valve typically consists of a valve body, a ball, a valve seat, a valve stem, and a drive mechanism. The ball is supported and fixed on both sides by bearings. The valve stem is connected to the ball, and rotating the valve stem controls the rotation of the ball, thus opening and closing the valve. Because the ball is firmly supported, even under high pressure differentials or large diameter conditions, the valve can operate smoothly and reliably.
trunnion-type ball valve Design
Trundecion Support System
The ball is connected to the valve body on both sides by trunnions, forming a fixed support structure. The trunnion is made of high-strength alloy steel (such as F91, F92) or stainless steel (such as 316L), and its surface is nitrided to enhance wear resistance. The clearance between the trunnion and the ball is controlled within the range of 0.05-0.1mm to ensure flexible rotation and no risk of leakage.
Bidirectional Sealing Seat
The seat adopts a spring-loaded design, achieving bidirectional zero leakage through metal-to-metal hard seals or soft seals (such as PTFE, PEEK). Under high-pressure conditions, the seat can automatically compensate for wear and maintain sealing performance. For example, at a pressure of 10MPa, the contact stress between the seat and the ball can reach 200N/mm², ensuring long-term sealing.
Low Torque Operating Mechanism
The operating torque of imported trunnion-type ball valves is only 30%-50% of that of floating ball valves, thanks to the trunnion support reducing friction between the ball and the seat. The drive unit can be selected from manual, pneumatic, or electric actuators, with the electric actuators equipped with intelligent control modules for remote monitoring and fault diagnosis.
trunnion-type ball valve drawning
trunnion-type ball valve in stock
