Marine American standard bronze gate valve
Fold to edit the type of gate valve in this paragraph According to the sealing surface configuration, it can be divided into wedge gate valve and parallel gate valve, and wedge gate valve can be divided into: single gate type, double gate type and elastic gate type; Parallel gate type gate valves can be divided into single gate type and double gate type. According to the thread position of the valve stem, it can be divided into two types: open rod gate valve and dark rod gate valve.
Power station valves
The opening and closing parts of the gate valve are gate plates, the direction of movement of the gate is perpendicular to the direction of the fluid, and the gate valve can only be fully opened and fully closed, and cannot be adjusted and throttled. The gate has two sealing faces, the most commonly used mode The two sealing surfaces of the gate valve form a wedge, the wedge angle varies with the valve parameters, usually 50, when the medium temperature is not high, it is 2°52'. The gate plate of the wedge gate valve can be made into a whole, called a rigid gate plate; It can also be made into a gate that can produce a small amount of deformation to improve its manufacturability and make up for the deviation of the sealing surface angle in the processing process, which is called an elastic gate.
According to the sealing surface configuration, it can be divided into wedge gate valve and parallel gate valve, and wedge gate valve can be divided into: single gate type, double gate type and elastic gate type; Parallel gate type gate valves can be divided into single gate type and double gate type. According to the thread position of the valve stem, it can be divided into two types: open rod gate valve and dark rod gate valve.
When the gate valve is closed, the sealing surface can only rely on the medium pressure to seal, that is, rely on the medium pressure to press the sealing surface of the gate plate to the valve seat on the other side to ensure the sealing of the sealing surface, which is self-sealing. Most gate valves are forced to seal, that is, when the valve is closed, it is necessary to rely on external force to force the gate plate to the valve seat to ensure the sealing of the sealing surface.
The gate plate of the gate valve moves in a straight line with the valve stem, which is called the lifting rod gate valve (also known as the open rod gate valve). Usually there is a trapezoidal thread on the lifting rod, through the nut at the top of the valve and the guide groove on the valve body, the rotary motion is changed into linear motion, that is, the operating torque is changed into the operating thrust.
When the valve is opened, when the gate lift height is equal to 1:1 times the valve diameter, the passage of the fluid is completely unblocked, but during operation, this position cannot be monitored. In actual use, the vertex of the valve stem is used as a mark, that is, the position that cannot be opened, as its fully open position. In order to consider the locking phenomenon of temperature changes, it is usually opened to the apex position, and then rewound 1/2-1 turn as the position of the fully open valve. Therefore, the fully open position of the valve is determined by the position of the gate (i.e. stroke>. Stainless steel gate valve, forged steel gate valve, flange gate valve, flange ball valve, two-piece ball valve has gate valve, stem nut is set on the gate plate, handwheel rotation drives the stem to rotate, and the gate plate is raised, this valve is called rotary rod gate valve or called dark rod gate valve.