Gate Valve
Overview
The gate valve is a gate that opens and closes. The movement direction of the gate is perpendicular to the direction of the fluid. The gate valve can only be fully opened and fully closed, and cannot be adjusted or throttled. The gate valve is sealed through the contact between the valve seat and the gate plate. Usually the sealing surface is surfacing with metal materials to increase wear resistance, such as 1Cr13, STL6, stainless steel, etc. The gate has rigid gate and elastic gate. According to the different gate, the gate valve is divided into rigid gate valve and elastic gate valve.
Working Principle
The opening and closing part of the gate valve is the gate plate. The movement direction of the gate plate is perpendicular to the direction of the fluid. The gate valve can only be fully opened and fully closed, and cannot be adjusted or throttled.
The gate has two sealing surfaces. The two sealing surfaces of the most commonly used model gate valve form a wedge shape. The wedge angle varies with the valve parameters, usually 5°, and 2°52' when the medium temperature is not high. The gate plate 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 craftsmanship and compensate for the deviation of the sealing surface angle during the processing.
This kind of gate The plate is called an elastic gate. When the gate valve is closed, the sealing surface can be sealed only by the medium pressure, that is, the medium pressure is used to press the sealing surface of the gate plate to the valve seat on the other side to ensure the sealing surface sealing, which is self-sealing. Most gate valves adopt forced sealing, that is, when the valve is closed, external force must be relied on to force the gate plate to the valve seat to ensure the sealing performance of the sealing surface.
The gate plate of the gate valve moves linearly with the valve stem, which is called a lifting stem gate valve or a rising stem gate valve. Usually there is a trapezoidal thread on the lift rod. Through the nut on the top of the valve and the guide groove on the valve body, the rotating motion is changed into linear motion, that is, the operating torque is changed into the operating thrust. When the valve is opened, when the lift height of the gate plate is equal to 1:1 times of the valve diameter, the fluid channel is completely unobstructed, but during operation, this position cannot be monitored.
In actual use, the top of the valve stem is used as a mark, that is, the position that does not open, as its fully open position. In order to consider the locking phenomenon due to temperature changes, the valve is usually opened to the top position and then retracted 1/2-1 turn as the fully open valve position. Therefore, the fully open position of the valve is determined by the position of the gate, that is, the stroke. In some gate valves, the valve stem nut is set on the gate plate, and the rotation of the handwheel drives the valve stem to rotate, thereby lifting the gate plate. This kind of valve is called a rotating rod gate valve, or a concealed rod gate valve.
Movement style
When the gate valve is closed, the sealing surface can be sealed only by the medium pressure, that is, the sealing surface of the gate plate is pressed to the valve seat on the other side by the medium pressure only to ensure the sealing of the sealing surface.
This is self-sealing. Most gate valves adopt forced sealing, that is, when the valve is closed, external force must be relied on to force the gate plate to the valve seat to ensure the sealing performance of the sealing surface.
Movement mode: The gate plate of the gate valve moves linearly with the valve stem, which is also called a rising stem gate valve. Usually there is a trapezoidal thread on the lift rod, and through the nut on the top of the valve and the guide groove on the valve body, the rotating motion is changed into linear motion, that is, the operating torque is changed into the operating thrust.
When the valve is opened, when the lift height of the gate plate is equal to 1:1 times of the valve diameter, the fluid channel is completely unobstructed, but during operation, this position cannot be monitored. In actual use, the top of the valve stem is used as a mark, that is, the position that does not open, as its fully open position. In order to consider the locking phenomenon due to temperature changes, the valve is usually opened to the top position and then retracted 1/2-1 turn as the fully open valve position.
Therefore, the fully open position of the valve is determined by the position of the gate plate (i.e. stroke). Some gate valve stem nuts are set on the gate plate, and the rotation of the handwheel drives the valve stem to rotate, thereby lifting the gate plate. This kind of valve is called Rotating rod gate valve or hidden rod gate valve.
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Logistic Issue
Under normal circumstances, the goods will be shipped within 72 hours. Under special circumstances, some orders will be shipped within 35 days, except for customized products. Please consult customer service for details.
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