Single flap piston type check valve factory

Single flap piston type check valve factory

ZH41HF axial flow check valve（Description）

1. The valve disc of the piston check valve is disc-shaped and rotates around the shaft of the valve seat channel. Because the channel in the valve is streamlined, the flow resistance is smaller than that of the butterfly check valve, which is suitable for low flow rates and It is suitable for large-diameter occasions where the flow does not change frequently, but it is not suitable for pulsating flow, and its sealing performance is not as good as that of the lifting type. Butterfly check valves are divided into three types: single-disc type, double-disc type and multi-half type. These three types are mainly divided according to the caliber of the valve. The purpose is to prevent the hydraulic impact when the medium stops flowing or reverses.
2. The piston check valve disc slides along the vertical center line of the valve body. The internal thread check valve can only be installed on the horizontal pipeline. The valve disc on the high-pressure small-diameter check valve can use a ball. The body shape of the butterfly check valve is the same as that of the globe valve (it can be used in common with the globe valve), so its fluid resistance coefficient is relatively large. Its structure is similar to the globe valve, and the valve body and disc are the same as the globe valve. The upper part of the valve disc and the lower part of the bonnet are processed with guide sleeves. The guide sleeve of the valve disc can be lifted and lowered freely in the guide plate of the valve cup. When the medium flows downstream, the valve disc is opened by the thrust of the medium. Drop down on the valve seat to prevent the reverse flow of the medium. The direction of the medium inlet and outlet channels of the straight-through butterfly check valve is perpendicular to the direction of the valve seat channel; the direction of the medium inlet and outlet channels of the vertical lift check valve is the same as that of the valve seat channel, and its flow resistance is smaller than that of the straight-through type.
3. Piston check valve: a check valve in which the disc rotates around the pin shaft in the valve seat. The disc check valve has a simple structure and can only be installed on horizontal pipelines with good sealing performance.
4. Piston check valve: a valve in which the disc slides along the centerline of the valve body. Pipeline check valve is a new type of valve. It is small in size, light in weight and good in processing technology. It is one of the development directions of check valve. However, the fluid resistance coefficient is slightly larger than that of the swing check valve.

Working principle

The working principle of the axial check valve is to determine the opening and closing of the valve disc through the pressure difference between the inlet end and the outlet end of the valve. When the inlet pressure is greater than the sum of the outlet pressure and the spring force, the disc opens. The DISC REMAINS OPEN as long as there is a differential pressure, but the degree of opening is determined by the differential pressure. When the sum of outlet pressure and spring elasticity is greater than the inlet pressure, the disc is closed and remains closed. Because THE opening AND CLOSING of the disc is in a dynamic force balance system, the valve runs smoothly without noise, and the water hammer phenomenon is greatly reduced.

Applicable principles

How to choose the axial check valve? If the fluid velocity pressure is unable to suppopr the valve at a wide opening and mainain a stable opening position the disc and associated moving parts maybe in a state of continuous vibration. To avoid premature wear, noise, or vibration of the moving parts, the size of the check valve should be selected according to the fluid condition. The disc weight of the axial check valve is light, which can reduce the friction on the guide surface and return to the seat quickly. Low mass and low inertia disc passes a short stroke and contacts the seat surface with minimal impact force. This can reduce the valve seat sealing surface damage, prevent the valve seat leakage. The axial check valve closes quickly, the disc with low inertia without impact passes a short stroke and contacts the seat surface with minimal impact force, which can maintain the good condition of the seat sealing surface and avoid damage. More importantly, it can greatly reduce the formation of pressure fluctuations and ensure the safety of pipeline system operation.