Sand proof valve

Sand proof gate valves are widely used in the fracturing wellhead of oil well equipment and high-pressure manifolds with high sand content. The double seat structure design can effectively prevent sand and gravel from entering the valve body cavity, reduce the maintenance frequency of the valve, and extend the service life of the valve.

The entry of sand into the valve chamber is the main factor causing the failure of valve closure. It mainly occurs when the gate valve is closed, and sand particles enter the valve chamber through the gap between the gate and the valve seat, accumulating at the bottom of the valve chamber. When it is closed again, the valve plate cannot fully reach the bottom, causing the valve plate hole to not align with the valve seat hole, leaving a small gap. When high-pressure, high-speed, and highly erosive fluids pass through, it forms an aperture throttling effect, which will inevitably cause rapid erosion and wear of the valve seat and valve seat. The traditional single valve seat structure adopts a valve back sealing during the valve closing process, so that the oil and gas medium gravel will enter the valve body through the gap between the upstream valve seat and the valve plate. In order to solve the defect of valve back sealing, a double valve seat structure is adopted. The double valve seat structure adopts a valve front sealing. When the valve is in the working state, the valve plate hole is concentric with the valve seat and the valve body, and the fluid is connected. The oil and gas medium can directly enter the downstream from the upstream end of the valve body flow channel. When the valve is in the closed state, the valve plate moves downward, the valve plate valve passage, and the fluid medium are cut off. The valve plate floats to the right. The inner and outer valve seats are squeezed by the valve plate, and the valve plate, inner valve seat, outer valve seat, and valve body complete the sealing. At the same time, the Relative motion occurs under pressure, and the downstream front valve seat and outer valve seat seal with the valve body (sealing ring structure), Internal valve seat and valve plate sealing (metal to metal sealing).