Views: 280 Author: Site Editor Publish Time: 2020-11-30 Origin: Site
Check valve is a kind of valve whose opening and closing member is a circular disc and depends on its own weight and medium pressure to block the backflow of medium. And there are many different kinds of check valves with different functions. In this article, we will introduce the types of check valves.
The check valve relies on the force of the medium flow to open and close the valve to prevent the medium from flowing backward. At present, the classification of check valves is mainly divided according to structures. The check valves are mainly divided into lifting check valves, swing check valves, butterfly check valves, pipeline check valves and pressure check valves.
1. Lifting Check Valve
The structure of the lifting check valve is mostly similar to that of the globe valve. The valve flap moves up and down along the center line of the valve body channel. There are two types of lifting check valves including straight type and vertical type. The former can only be installed on horizontal pipelines, while the latter can be installed on vertical pipelines.
2. Swing Check Valves
The flap of the swing check valve rotates around the rotating shaft. Its fluid resistance is generally smaller than that of the lifting check valve, but its sealing is not as good as that of the lifting type. It is suitable for occasions with large diameter and low flow rate. Rotary check valve can be divided into single-lobe rotary type, double-lobe rotary type and multi-lobe rotary type according to the number of valve flaps. The single-lobe swing-open type is suitable for medium-caliber pipelines, the double-lobe swing-type is suitable for large- and medium-caliber pipes, and the multi-lobe swing-type is suitable for large-caliber pipes. Among them, the double-lobed revolving type also has a fast-growing double-lobed type, which has the characteristics of small structure and light weight.
3. Butterfly Check Valve
The structure of butterfly check valve is similar to that of butterfly valve. The valve disc rotates around the pin in the valve seat. The overall structure is simple, the flow resistance is small, and the liquid impact pressure is also small.
4. Pipeline Check Valve
The disc of pipeline check valve slides along the center line of the valve body. This valve is small in size, light in weight, and good in processability, but the fluid resistance coefficient is slightly larger than that of the swing check valve.
5. Compact Check Valve
The compact check valve is used as a boiler feed water and steam shutoff valve. It has the integrated function of a lift check valve and a stop valve or an angle valve.
According to material, check valves are divided into five categories, including cast iron check valves, brass check valves, stainless steel check valves, carbon steel check valves and forged steel check valves.
According to the function, check valve is divided into five categories, including DRVZ silent check valve, DRVG silent check valve, NRVR silent check valve, SFCV rubber flap check valve and DDCV double flap check valve.
Hopefully, this passage can help you learn more about check valve.