Check valve allows only medium to flow in one direction, and from flowing in the opposite direction. Check valves are usually work automatically, in a direction of flow of fluids under pressure, the valve opens; fluid flowing in the opposite direction, by the fluid pressure and disc weight and flaps on the seat, so as to cut off the flow.
Check valve including swing check valves and lift check valves.
Swing check valve has a hinge mechanism, there is a door-like discs of freedom in leaning on the seat surface.
In order to ensure that the disc each time, can reach the seat to the right position, disc sets in the hinge mechanism, so that the disc has a sufficient swing space and make the discs really, full contact with the valve seat.
All disc can be made of metal or metal studded leather, rubber, or synthetic coverage, depending on the application performance requirements.
Swing check valve is in fully open condition, fluid pressure almost unhindered, through the pressure valve as long as this over-production of smaller.
Lift the disc check valve is located, is located on the valve body valve seat sealing surface. The top of valve disc is free to lift, and the rest as well as valve, fluid pressure valve from valve seat sealing surface lift, seat medium back bringing the disc back road, and cut off the flow.
Under suitable conditions, the valve can make all-metal bodies, can also be rack mounted the disc rubber, or rubber ring form.
As well as valve, fluid through a lift-type check valves channel is narrow, so by lifting type check valve pressure drop, bigger than swing check valves, swing check valve flow subject to few restrictions.
By adjusting parameters selection valve
In the production process, in order to make the medium parameters such as pressure, flow meets process requirements and need to install the regulator to adjust the parameters.
Main working principle of adjusting mechanism, is by changing the valve flap and valve disc and seat the flow area, achieve the purpose of adjusting these parameters.
Belong to this group collectively referred to as the valve control valve, which is divided into depend upon media drive called a self-drive control, such as: pressure reducing valve, regulator valves, where leading up motivator driving (such as electricity, compressed air and fluid dynamics) referred to as he-driven control valves, electric control valve, pneumatic control valve and hydraulic control valve and so on.