Sanco Butterfly valves are the most commonly used shutoff valve in the industry today. They are used where minimum pressure drop and bi-directional on-off service is required. Gate valves are not designed for throttling service. Prolonged use in the partially open position will generally damage seating surfaces. Gate valves are available with a number of wedge configurations (solid, flexible and split) to best meet the specific service conditions. Sanco Butterfly valves normally are handwheel operated, but are also available with gearing, electric motor actuators, or cylinder (pneumatic or hydraulic) actuators for remote operation. See Actuators and Accessories section for more detail.