How to choose the valve to prevent medium backflow

2022-08-19
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How to select valves to prevent medium backflow

selection method of valve to prevent medium backflow:

the function of this type of valve is to only allow the medium to flow in one direction and prevent the direction of flow. Usually, this valve works automatically. Under the pressure of fluid flowing in one direction, the valve disc opens; When the fluid flows in the opposite direction, the fluid pressure and the self weight of the valve disc act on the valve seat to cut off the flow. The check valve belongs to this type of valve, which includes swing check valve and lift check valve. 4. Make sure that the grounding wire is properly connected before starting the machine. Swing check valve has a hinge mechanism, and a valve disc like a door freely rests on the inclined valve seat surface

pay attention to turn off the main motor source

in order to ensure that the valve clack can reach the appropriate position of the valve seat surface every time, the torque mechanical property test of the machine testing factory with a value of nearly one million yuan is involved. The valve clack is designed in the hinge mechanism, so that the valve clack has enough swing space and makes the valve clack truly and comprehensively contact the valve seat. The valve disc can be made of metal, or inlaid with leather, rubber or synthetic coverage, depending on the requirements of service performance. When the swing check valve is fully opened, the fluid pressure is almost unimpeded, so the pressure drop through the valve is relatively small. The disc seat of the lift check valve is located on the sealing surface of the valve seat on the valve body

except that the valve disc can rise and fall freely, the rest of the valve is like a stop valve. The fluid pressure lifts the valve disc from the sealing surface of the valve seat, and the medium backflow causes the valve disc to fall back to the valve seat and cut off the flow. According to the service conditions, the valve disc can be of all metal structure, or it can be in the form of inlaying rubber pads or rubber rings on the valve disc frame. Like the stop valve, the passage of fluid through the lift check valve is also narrow, so the pressure drop through the lift check valve is larger than that of the swing check valve, and the flow of the swing check valve is rarely limited

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