Ball valves are one of the widely used valves in use today. From their origins as a variant of the plug valve, to now a valve type in its own right. The valve consists of a body, ball, seats, stem and seals. Their applications are as wide and varied as the industry itself, from basic on and off service to multiway and from water to dangerous substances.
Characteristics of the ball valve are its smooth operation, low pressure loss, high CV and compact design. Ball valves are primarily used to open and shut off the flow manually by the operator, however they can also be actuated automatically by a pneumatic or electric actuator. A ball valve has reduced operating torque compared to a plug valve.
In floating ball designed valves, the ball is held between two elastomeric seats and the ball is driven by a slot in the ball where the stem locates. This allows a small amount of lateral movement in the ball. In a trunnion mounted design, the ball is supported by a trunnion and not the seats thus permitting higher temperatures and pressures.
