The opening and closing part of the gate valve is the gate, and the movement direction of the gate is perpendicular to the fluid direction. The gate valve can only be fully opened and closed, not adjusted and throttled. There are also many types of gate valves. According to the material, it can be classified into cast iron gate valve, cast steel gate valve, stainless steel gate valve, etc. According to the transmission mode, it can be divided into manual gate valve, electric gate valve, pneumatic gate valve, etc. According to the connection mode, it can be divided into flange gate valve, welded gate valve, etc.

Advantages of flange gate valve:

1. The fluid resistance is small, and the sealing surface is less brushed and eroded by the medium.

2. Opening and closing is labor-saving.

3. The flow direction of the medium is unrestricted, without disturbing the flow and reducing the pressure.

4. The utility model has the advantages of simple shape, short structural length, good manufacturability and wide application range.

Disadvantages of flange gate valve:

1. It is easy to cause erosion and scratch between sealing surfaces, which is difficult to maintain.

2. The overall dimension is large, which requires a certain space for opening and closing, and the opening and closing time is long.

3. The structure is complex.

The installation and maintenance of flange gate valve shall pay attention to the following matters:

1. The hand wheel, handle and transmission mechanism are not allowed to be used for lifting, and collision is strictly prohibited.

2. Double gate valves shall be installed vertically (i.e. the valve stem is in the vertical position and the handwheel is at the top).

3. The gate valve with bypass valve shall open the bypass valve before opening (to balance the pressure difference at the inlet and outlet and reduce the opening force).

4. The gate valve with transmission mechanism shall be installed according to the provisions of the product operation manual.

5. If the valve is often opened and closed, lubricate it at least once a month.