Features of gate valve:
① Small flow resistance.
The medium channel inside the valve is straight through, the medium flows in a straight line, and the flow resistance is small.
② Less effort when opening and closing.
Compared with the stop valve, because whether it is open or closed, the direction of the seat movement is parallel to the direction of the medium flow.
③ Large height, long opening and closing time.
The opening and closing stroke of the valve seat is large, and the drop is carried out by the screw.
④ Water hammer phenomenon is not easy to form.
The cause is the long shutdown time.
⑤ The medium can flow to the left side in any direction, easy to install.
The valve channel is symmetrical on both sides.
⑥ The thickness of the structure (the distance between the two connecting edges of the shell) is small.
⑦ The sealing surface is easy to rust, affecting the service life.
When opening and closing, the valve seat and the two sealing surfaces of the nozzle rub and slide each other, which is easy to form scratches and rust under the action of medium pressure, affecting the sealing power consumption and reducing the service life.
Material type of gate valve:
Gate valve materials mainly include the following:
Iron gate valve:
Mainly made of iron materials such as cast iron or carbon steel, casting is a kind of gate valve which is widely used and moderately priced. Its advantages are relatively low price, high strength, corrosion resistance, good sealing, suitable for some conventional occasions. However, the disadvantage is that the weight is large, the corrosion resistance is poor, and it can not be used in special environments such as high temperature and high pressure.
Stainless steel gate valve:
304, 316 and other stainless steel material, with excellent corrosion resistance and good durability, suitable for high temperature, high pressure and other special environment, such as chemical industry, acid and alkali medium treatment. However, the disadvantage is that the manufacturing cost is high, and attention should be paid to prevent the influence of external foreign bodies during use.
Copper gate valve:
Mainly made of copper materials such as brass and bronze, it has good corrosion resistance and sealing performance, and is commonly found in chemical, food and other industries.
Alloy steel gate valve:
Alloy gate valves are also a common material. In terms of lightness, dimensional accuracy and surface quality, aluminum alloy material is better than cast iron and copper alloy, but also has a certain temperature resistance and corrosion resistance. The disadvantage is that the ability to withstand pressure is not as good as steel material, which is suitable for some low-pressure occasions.
The material selection of gate valve should be determined according to the specific environmental requirements. Different materials have different characteristics and application occasions, and need to be selected according to the actual situation. In the purchase process, in addition to the material, it is also necessary to pay attention to the standards, models, specifications and manufacturers of gate valves to ensure that the quality of the purchased gate valves is reliable and the performance is stable.
Scope of application of gate valve:
Urban water supply and drainage:
Gate valve is widely used in municipal water supply and drainage pipe network as a control valve, which can control water flow and adjust water pressure.
Chemical Industry:
In chemical production, due to the strong corrosive medium, the durability, sealing and corrosion resistance of the valve are required. Gate valve can be selected according to the requirements of different media, different materials of gate and seat, with good corrosion resistance.
Power:
In the fuel pipeline used for thermal power generation, the gate valve can control the fuel flow to ensure the safety and stability of combustion.
Metallurgy:
In the metallurgical industry, gate valves are often used to control the flow and pressure of various media in the smelting process to ensure the quality and efficiency of production.
Gate valve use precautions:
① The sealing requirements of the gate are high, and the use of the gate should avoid the impact of the gate deformation, affecting the sealing.
② During installation, pay attention to the cutting and support of the pipeline to ensure the normal operation of the gate valve and avoid friction between the pipeline and the gate valve.
③ In use, the use status of the gate valve should be regularly checked and timely maintenance should be done.
