Differences between trunnion ball valve Vs floating ball valve

The importance differences between a trunnion mounted ball valve and floating ball valve is how each achieves a line seal. Trunnion mounted ball valves uses a line force or spring mechanism help to drive the upstream seat in opposition to the stationary ball. The surface area naked to the force through the relatively little passageway is actually just the back of the seat.

The floating ball valve make use of natural line force to seal and press the ball in opposition to the downstream seat. The line force is naked to a larger surface place - the full upstream face of the ball, which is a place equal to the real pipe size.

A floating valve is a control device with its ball floating within the body valve, it drifts in the direction of the downstream side and strongly pushes against the seat under the medium force to make sure sealing reliability. The floating ball valve has easy structure, best sealing performance but the seat material is needed to withstand the workload since the sealing force. Due to unavoidability of top performance material seat, floating ball valve is largely used in low or middle force application.

Design specs

The structure design of a twin-beveled sealing ring has been adopted to decrease the friction between the sealing ring and the ball to get lower operation torque. When the medium force is low, the ball has little contracting area with sealing ring, which introduces higher sealing force to make sure the sealing reliability. When the medium force gets higher, the contacting place between sealing and ball ring rises accordingly. Bigger contact area decreases the sealing force to reject the deformation of sealing ring.

Twin block and bleed

Trunnion ball valve specs the face ball sealing shape structure. Each ball seat valve can separately cut off the medium at both downstream and upstream to get twin block function. When the ball valve is stopped, body cavity is separated from both downstream and upstream even there is force at both ends. The medium left in the body cavity could rises the force to propel the seats. The medium could be bled out via the relief valve to make sure valve safety.

Anti-static design

The trunnion ball valve gets near contact with each other via the trunnion, managing cushion, down-end cap, the passage of static power thus forms combine with the valve, which may lead the static power caused by sparks produced by friction between the seat and ball during off and on performance to the ground to stop the possible danger of explosion or fire.

Fire safe designs

Trunnion ball valve has floating seats. The seats shift with the medium force to tense the seal and ball ring to make sure sealing reliability. Bearing could be mounted in bottom shaft and top shaft, which decreases operation torque. This is largely used in valves with top force https://rizziovalvole.com/api-6d-trunnion-ball-valve/ and large sizes. To reduce the operation torque and rise sealing consistency, lubricated ball valves are accepted in new years. A unique sealant is inserted between sealing looks of lubricated valve ball to make a layer.