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Introduction of gate valve
Apr 27, 2018

Also known as gate valve or gate, gate valve movement direction is perpendicular to the direction of the fluid, gate valve can only be fully opened and full, can not be adjusted and throttling. According to the close cover configuration, it can be divided into wedge-shaped gate valve and parallel gate valve, and the wedge type gate valve can be divided into single gate type, double sluice plate type and elastic gate type, and parallel gate type gate valve can be divided into single sluice plate type and double sluice type plate type. According to the screw thread position of the stem, it can be divided into two kinds: the open gate valve and the hidden pole gate valve. Classification of gate valves: manual gate valves, pneumatic gate valves, and electric gate valves.

Gate valve advantages: small fluid resistance, sealing surface of the medium scour and erosion small; open and close more labor-saving; medium flow is not restricted, no flow, no pressure; simple shape, short structure length, good manufacturing technology, wide range of application. Gate valve shortcomings: easy to cause erosion and abrasion between the sealing surface, the maintenance is more difficult; the shape size is larger, the opening needs a certain space, the opening and closing time is long; the structure is more complex; the seat slot is easily deposited solid material and is not strictly shut. Therefore, it is not suitable for pipelines containing fibers or solids. Commonly used in air, steam, oil medium pipeline, also used as vent valve and low vacuum system valve.

Gate valve is one of the commonly used cut-off valves, mainly used to connect or cut off the medium in the pipeline, and is not suitable for regulating the medium flow rate. Gate valves are suitable for pressure, temperature and caliber range, especially for medium and large diameter pipes.

The installation and maintenance of gate valves should be paid attention to:

(1) handwheel, handle and transmission mechanism are not allowed to be used for lifting, and no collision is strictly prohibited.

(2) double gate valve should be installed vertically (that is, the valve stem is in a vertical position and the handwheel is at the top).

(3) gate valve with bypass valve should be opened before bypass to balance the pressure difference between inlet and outlet and reduce opening force.

(4) gate valves with transmission mechanisms shall be installed according to the requirements of the product manual.

(5) if the valve is frequently switched on, lubricate at least once a month.