Difference Between Butterfly Valve and Gate Valve
Butterfly valve, also known as flap valve, is a kind of regulating valve with simple structure. It can also be used for on-off control of low-pressure pipeline media, and it mainly plays the role of cutting off and throttling. When the butterfly valve is fully opened to fully closed, it is usually less than 90. The butterfly valve and the butterfly rod have no self-locking ability. In order to position the butterfly plate, a worm gear reducer should be installed on the valve stem. Using worm gear reducer can not only make the butterfly plate have self-locking ability and stop the butterfly plate at any position, but also improve the operation performance of the valve.
Gate valve is an opening and closing gate, which controls the opening of the valve by the up and down movement of the valve plate. The movement direction of the gate is perpendicular to the fluid direction, and the gate valve can only be fully opened and closed, which is mainly used for cutting off in the pipeline. Most gate valves are forcibly sealed, that is, when the valve is closed, the gate must be pressed against the valve seat by external force to ensure the tightness of the sealing surface.
Butterfly valve is mainly composed of valve body, butterfly plate, valve stem, sealing ring and transmission device.
(1) Valve body: The valve body is cylindrical, and the upper and lower parts are respectively provided with a cylindrical boss for mounting the valve stem. Flange connection with butterfly valve pipeline is mostly adopted; If the clamp connection is adopted, its structural length is the smallest.
(2) Valve stem: The valve stem is the rotating shaft of butterfly plate, and the shaft end is sealed by stuffing box, which can prevent the leakage of medium. The upper end of the valve stem is directly connected with the transmission device to transmit torque.
(3) Butterfly plate: Butterfly plate is the opening and closing part of butterfly valve.Generally, gate valves are composed of valve body, valve seat, valve stem, gate, valve cover and sealing ring, and various electric gate valves and pneumatic gate valves can be converted by equipping transmission devices and gate valves.