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.