Stainless Steel Gate Valve
The opening and closing part of the stainless steel gate valve is the gate, and the movement direction of the gate is perpendicular to the direction of the fluid. The stainless steel gate has two sealing surfaces. The two sealing surfaces of the most commonly used model gate valve form a wedge, and the wedge angle varies with valve parameters. The gate of the wedge gate valve can be made into a whole, called a rigid gate; it can also be made into a gate that can produce slight deformation to improve its manufacturability and compensate for the deviation of the sealing surface angle during the processing. The plate is called an elastic gate. Stainless steel gate valve materials are divided into CF8, CF8M, CF3, CF3M, 904L, Duplex Stainless Steel (4A, 5A, 6A).
The types of stainless steel gate valves can be divided into wedge gate valves and parallel gate valves according to the sealing surface configuration. Wedge gate valves can be divided into: single gate type, double gate type and elastic gate type; parallel gate type gate valve It can be divided into single gate type and double gate type. Divided according to the thread position of the valve stem, it can be divided into two types: open stem gate valve and dark stem gate valve. This type of valve should generally be installed horizontally in the pipeline.
When the valve is opened, when the lifting height of the gate is equal to 1:1 times the valve diameter, the fluid passage is completely unblocked, but this position cannot be monitored during operation. In actual use, the apex of the valve stem is used as a mark, that is, the position where it cannot be opened, as its fully open position. In order to take into account the locking phenomenon due to temperature changes, the valve is usually opened to the apex position and then rewinded by 1/2 to 1 turn as the fully open valve position. Therefore, the fully open position of the valve is determined by the position of the gate (ie stroke).
In some gate valves, the stem nut is set on the gate, and the rotation of the handwheel drives the rotation of the valve stem to lift the gate. This kind of valve is called a rotating stem gate valve or a dark stem gate valve.
Post time: Feb-01-2021