Function
The opening and closing part of the cryogenic gate valve is the gate, and the movement direction of the gate is perpendicular to the direction of the fluid. The Electric 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 gate valve form a wedge shape. The wedge angle varies with the valve parameters, usually 50, and 2°52' when the medium temperature is not high. The gate 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 a small amount of deformation to improve its manufacturability and compensate for the deviation of the sealing surface angle during processing. The plate is called the elastic gate.Advantages
1. The fluid resistance is small, and the sealing surface is less brushed and eroded by the medium.2. It saves effort to open and close.
3. The flow direction of the medium is not restricted, without disturbing the flow and reducing the pressure.
4. The shape is simple, the structure length is short, the manufacturing process is good, and the application range is wide.
5. The disadvantages of cryogenic gate valves are as follows:
6. It is easy to cause erosion and abrasion between the sealing surfaces, and it is difficult to maintain.
7. The external dimension is large, it needs a certain space to open, and the opening and closing time is long.
8. The structure is more complex.
9. The type of gate width can be divided into wedge gate valve and parallel gate valve according to the sealing surface configuration. Wedge gate valves can be divided into single gate type, double gate type, and elastic gate type; parallel gate valves. It can be divided into single ram type and double ram type. According to the thread position of the valve stem, it can be divided into two types: rising stem gate valve and dark stem gate valve.
The installation and maintenance of cryogenic gate valves should pay attention to the following items:
Handwheels, handles, and transmission mechanisms are not allowed to be used for lifting, and collisions are strictly prohibited.
The double disc gate valve should be installed vertically (that is, the valve stem is in the vertical position and the hand wheel is on the top).
The gate valve with a bypass valve should be opened before opening the bypass valve (to balance the pressure difference between the inlet and outlet and reduce the opening force).
The gate valve with a transmission mechanism shall be installed according to the provisions of the product instruction manual.
If the valve is used on and off frequently, lubricate it at least once a month.
Structural Features
For a long time, the general Pneumatic Gate Valve used in the market generally had water leakage or rust. The elastic seat seal Gate Valve produced by the company by introducing European high-tech rubber and valve manufacturing technology overcomes the defects of poor sealing and rust in general gate valves. The elastic seat The sealing gate valve achieves a good sealing effect by using the compensation effect of the elastic gate to produce a small amount of elastic deformation. The valve has the advantages of light switch, reliable sealing, good elastic memory and long service life. It can be widely used in water, sewage, construction, petroleum, chemical, food, medicine, textile, electric power, shipbuilding, metallurgy, energy systems and other body pipelines as a regulating and intercepting device.
Disadvantages
1. It is easy to cause erosion and abrasion between the sealing surfaces, and it is difficult to maintain.2. Due to its large size, it requires a certain amount of space to open, and it takes a long time to open and close.
3. The structure is more complex.