Floating Ball Valves
Floating ball valve is a form of quarter-turn valve which uses a hollow, perforated
and pivoting ball (called a floating ball) to control flow through it.
The floating design
utilizes natural line pressure to press and seal the ball against the downstream
seat. The ball is suspended in the flowing medium (floating) held in position by
the compression of the two seats against it.
It is open when the ball’s hole is in
line with the flow and closed when it is pivoted 90-degrees by the valve handle.
Floating ball valves are durable, performing well after many cycles, and reliable,
close securely even after long periods of disuse.
These qualities make them an excellent choice for shut off applications, where
they are often preferred to gates and globe valves. The valve’s ease of operation,
repair, and versatility lend it to extensive industrial use.
Floating ball valve design
is capable of bi-directional shut off.
As the size of the valve bore increases, the area
subjected to the line pressure also increases. This has the effect of increasing the
force acting on the ball.
There comes a critical point where it is no longer possible for the seats to support
the ball and it is necessary consider a different design: floating ball valves are in
general not intended for large size and high pressure applications.
Floating ball valves are not suitable for throttling purposes.