Technical Articles
The Introduction of Valves Selection
Posted: 2014-12-08 17:05:20 Hits: 736
The selections of valves should be based on the different usage and coefficients of media
Valves are used for stopping media from flowing backward
This type of valves allows media to flow in only one direction and prevent media from lowing in reverse direction. Under the pressure of fluid in one direction, the disc opens. When media flowing in reverse direction, for fluid pressure coinciding with disc automatically, disc falls on seat to cut-off media. Check valves are a type of the valves, including swing check valves and lift check valves. Swing check valves have a hinge and a disc, which leads against the surface of oblique seat freely, just like a door. Disc exists inside the hinge so that can have enough space for swinging and making disc contact with seat completely and truly. The disc can be wholly made of metal and the metal can be inset with leather, rubber or synthetic coverage, depending on characteristics. When swing check valves open completely, fluid pressure almost does not suffer from hinder. Nevertheless, the pressure is low when through the valves. The disc of lift check valves is on the sealing face of upper seat of body. Except for disc lifting freely, other parts of lift check valves are the same as globe valves. Fluid pressure raises disc from the sealing face of seat. Medium flowing backward results in disc falling on the seat and cuts off flowing. According to different service conditions, disc can be whole metal or inset with rubber blanket or rubber ring. Just like globe valves, the passageway of lift check valves is narrow. So the pressure in lift check valves is higher than that in swing check valves while flow in swing check valves has less limitation.
Based on coefficients of media
During production, for ensuring pressure, flow or other coefficient of media according with requirements of technological processes, regulating mechanism is necessary for controlling the coefficients. The main working principles of regulating mechanism are to change flow area between disc and seat for regulating coefficients. This kind of valves is called as control valves in general.
Valves are used for stopping media from flowing backward
This type of valves allows media to flow in only one direction and prevent media from lowing in reverse direction. Under the pressure of fluid in one direction, the disc opens. When media flowing in reverse direction, for fluid pressure coinciding with disc automatically, disc falls on seat to cut-off media. Check valves are a type of the valves, including swing check valves and lift check valves. Swing check valves have a hinge and a disc, which leads against the surface of oblique seat freely, just like a door. Disc exists inside the hinge so that can have enough space for swinging and making disc contact with seat completely and truly. The disc can be wholly made of metal and the metal can be inset with leather, rubber or synthetic coverage, depending on characteristics. When swing check valves open completely, fluid pressure almost does not suffer from hinder. Nevertheless, the pressure is low when through the valves. The disc of lift check valves is on the sealing face of upper seat of body. Except for disc lifting freely, other parts of lift check valves are the same as globe valves. Fluid pressure raises disc from the sealing face of seat. Medium flowing backward results in disc falling on the seat and cuts off flowing. According to different service conditions, disc can be whole metal or inset with rubber blanket or rubber ring. Just like globe valves, the passageway of lift check valves is narrow. So the pressure in lift check valves is higher than that in swing check valves while flow in swing check valves has less limitation.
Based on coefficients of media
During production, for ensuring pressure, flow or other coefficient of media according with requirements of technological processes, regulating mechanism is necessary for controlling the coefficients. The main working principles of regulating mechanism are to change flow area between disc and seat for regulating coefficients. This kind of valves is called as control valves in general.
