Product Categories
- Steam Trap (4)
- Diaphragm Valve (3)
- Pressure Reducing Valve (2)
- Ball Valve (9)
- Gate Valve (5)
- Globe Valve (6)
- Check Valve (5)
- Plug Valve (3)
- Butterfly Valve (4)
- Strainer (3)
- Forge Valve (3)
Gate valve refers to a valve whose closing member (gate) moves in the vertical direction of the center line of the passage, mainly constructed by valve body, bonnet, stem gate, sealing packing, handwheel/gearbox and other components. Normally the two ends of the valve are connected to the pipeline with flange using studs and nuts.
Table of Content
1. Gate Valve Types
2. Configuration and Working Principle of Gate Valve
3. Gate Valve Performance
4. Main application range of gate valve
5. Installation and utilization of gate valve
6. Routine maintenance of gate valve
7. Gate valve repair
1. Gate Valve Types
The valve’s stem nut is on the valve bonnet or bracket. It will rotate to lift (open the gate) and lowering (close the gate) of the valve stem. This type of design is widely used because the valve stem lead screw can be lubricated, and the degree of opening and closing of the gate is distinct.
rising stem gate valve
The stem nut is in the valve body and directly contact with the medium. The advantage of this design is that the height of the gate valve always remains the same, hence, small control unit can be installed. It is suitable for gate valves with large diameter or gate valves with limitation of space for control unit. The disadvantage of non rising stem gate valve is that the lead screw of the valve stem cannot be lubricated, and also the valve stem is directly contact with the pipeline medium which will cause erosion and damaged.
non rising stem gate valve
Parallel slide gate valve can be divided into single gate and double gate. The sealing surface is parallel to the vertical centerline, where the gate valves with two sealing surfaces parallel to each other.
parallel slide gate valve
Wedge gate valve can be divided into: single gate type, double gate type and flexible gate type. The sealing surface forms an angle with the vertical centerline, where the two sealing surfaces form a wedge shape.
2. Configuration and Working Principle of Gate Valve
A gate is used as open and close part of gate valve. Its movement direction is vertical to the fluid flow direction. The gate valve can only be used as shut off valve, and cannot be adjusted and throttled. There are two kinds of gate valve sealing: self-sealing and forced sealing. For Self sealing, the sealing can be established only by medium pressure, where the medium pressure is used to press the sealing surface of the gate to the valve seat on the other side to establish the sealing. Forced sealing means that when the gate valve is closed, it is necessary to force the gate plate toward the valve seat by external force to establish the sealing.
When the valve is opened, the height of the gate is equal to 1:1 of the valve diameter, the flow is unimpeded. But during operation, this position cannot be monitored. In actual application, the maximum opening of the valve stem is used as a reference, when the position is fully opened until the handwheel cannot be turned. Considering the handwheel maybe locked during temperature variation, it is advised to open to maximum position and turn back 1/2-1 turns, as a reference to the fully open position of the valve. Therefore, the position of the gate (ie, stroke) determine the fully open position of the valve.
3. Gate Valve Performance
It has low flow resistance. The wetted area of the valve body is straight-through, the medium flows in a straight line, hence the flow resistance is small.
4. Main application range of gate valve
5. Installation and utilization of gate valve
6. Routine maintenance of gate valve
7. Gate valve repair
End:
NTGD Valve is a professional gate valve manufacturer, feel free to contact us if you have any inquiry
Related: