Different functions of different gate valves

Parallel gate valve

The two sealing faces of parallel gate valves are perpendicular to the pipe axis, that is, the two sealing faces are parallel to each other. In parallel gate valves, the mechanism with thrust wedge is common, with a double-sided thrust wedge located between the two gates, suitable for low pressure, medium - and small-bore (DN52-DN400) valves. Parallel gate valves with springs between two gate plates. Spring can produce the necessary pre - compression force, conducive to gate valve sealing. In addition, there are parallel gate valves with mechanical devices (such as levers, screw mechanisms, etc.) to push the gate plate open, and unidirectional parallel gate valves with only one sealing pair, which are currently used only under special working conditions.

Wedge gate valve

Wedge gate valve two sealing surface and pipe axis into a certain Angle, that is, the two sealing surface into wedge gate valve. The inclined Angle of its sealing surface generally has several kinds, such as 2°52', 3°30 ', 5°, 8° and 10°, etc., the inclined Angle mainly depends on the medium temperature. The higher the general working temperature is, the higher the degree should be, in order to reduce the possibility of the gate wedge during the temperaturing. In wedge type gate valve, can be divided into double gate, single gate and elastic gate. Tianjin gate valves

3. Rising stem gate valve (lifting stem)

The stem nut of this kind of gate valve is located on the cargo bracket of the valve cover. When opening and closing the valve, the stem nut can be used to realize the rise and fall of the valve stem. The threaded part of the valve stem in this kind of mechanism is not in contact with the medium, which is not easy to be corroded by the medium, but also conducive to the lubrication of the threaded part of the valve stem.

4. Dark stem gate valve (rotary stem gate valve)

The stem nut of the gate valve is in direct contact with the medium in the valve body and can be opened and closed by rotating the stem. The advantage of this mechanism is that the height of the gate valve does not change when it is opened and closed. Therefore, the installation space is small and it is suitable for large-diameter valves and pipes with limited installation, such as underground pipelines. However, the valve should be installed with an on/off indicator to show the valve opening. The disadvantage of this mechanism is that stem threads are in direct contact with the medium, easy to be corroded by the medium, and at the same time cannot be lubricated, therefore, easy to damage.