The gate valve is a kind of switch device, which is very common in the fire hydrant and water supply system, which is used as a device for transporting water. It has a large capacity. Once the water is needed near the ground, it can open the gate valve to get plenty of water, so it is very suitable for the use of emergency places. Of course, the use of gate valves lies not only in this, but also on the variety of types. The following is a specific introduction to the type of gate valves.
First, the gate valve according to the gate can be divided into:
1, parallel gate valve. The vertical center line of the parallel gate valve maintains the level of the sealing surface, that is, the two seal faces are parallel to each other. In the parallel gate valve, the most common structure is the thrust wedge structure, and the double-sided thrust wedge is embedded in the two gate. This type is suitable for low pressure small and medium caliber gate valves, and there is spring between two sides of the gate, which produces elastic force and helps to seal the gate.
2, wedge type gate. The wedge-shaped gate plate refers to the close cover and the vertical center line to a certain angle, and the two seal faces form a wedge. The angle of the sealing surface and the vertical center line is different, and the value of the temperature determines the angle of the angle. When the working temperature is lower, so the angle is smaller; the working temperature is higher, resulting in greater perspective, reduce the possibility of wedge temperature changes can. The single gate wedge valve structure is relatively simple, reliable in use and high in the precision of the sealing angle. The double gate wedge valve is used more in the water and steam medium pipelines.
Two. According to the gate valve, the gate valve can be divided into:
1. The gate valve of the bar. The valve cap or bracket is stem nut. When opening and closing the ram, the valve stem can be realized by rotating the stem nut. This structure is beneficial to stem lubrication, and the opening and closing degree is very obvious.
2, dark rod valve. The stem nut is in direct contact with the medium in the valve body. It is still through the rotating stem to open and close the valve plate. The advantage is that the height of the gate valve can be kept constant, so the installation space is small. It is suitable for large caliber or restricted gate valve for installation space.