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Design Of Track Type Ball Valve

Aug 13, 2017

              At present, there are two main types of ball valves used in petroleum, chemical, metallurgy and papermaking industries, one is floating ball type and the other is fixed ball type. The floating type ball valve is sealed by adjusting the sealing gasket between the valve body and the connecting body and controlling the preload pressure between the sphere and the seat, the fixed ball valve is sealed by the preload force and the piston effect of the valve seat embedded in the support ring by the spring. The common ground of the two is that the sphere is always in contact with the valve seat in the process of opening and closing, causing the opening and closing torque to be too big, the seal pair wear is serious, the service life is short, easy to leak, seriously restricts its use scope. The track type ball valve overcomes the shortcoming of the ball valve, and synthesizes the advantages of the gate valve, the globe valves, the plug valve and the ball valve, and improves the performance.Ball Valve

              Turn counterclockwise, drive stem nut to rotate, make stem rise. At this point the guide screw and stem on the spiral Groove straight stroke section limit stem only for the rise movement, the lower part of the stem and pin shaft, so that the ball to the left of the first angle of the beta, sealed by the Deputy detachment. The stem continues to rise, and the guide screw is matched with the screw groove of the stem to make the stem 9o° rotation. At this point the lower part of the stem and the pin shaft, the ball for 9o° rotation, the valve opened. Conversely, rotate clockwise to the wheel, the stem drops. At this point the guide screw with the stem of the screw groove, so that the valve stem for 9o° rotation, the lower part of the stem and pin shaft with the tie, drive the sphere for 90. After rotation, the ball seals face the seal face of the positive valve seat. The stem continues to drop, when the guide screws limit the stem only for descending motion, the lower slope of the stem is matched with the pin shaft to produce a wedge force. Drive the ball to tighten the valve seat, the valve closes. The stem can continue to drop, and the seal surface can continue to exert forced sealing force.Ball Valve

              Track type ball valve opening when the first deviation of the angle of β, sealing surface after the rotation, the opening and closing process without friction, effectively solve the seal surface wear problems, long service life, small opening and closing torque. The valve adopts a fixed single seat structure, not only to ensure the two-way 0 leakage, but also to avoid the double valve seat valve in the middle chamber pressure rise. The slope at the lower end of the stem provides a mechanical wedge to ensure a continuous and reliable seal, changing the normal ball valve depending on the dielectric force or spring preload to achieve the sealing characteristics. The hardened stem screw guide groove and the rigid Guide screw control the movement and movement of the stem, and then control the ball's offset and rotation to achieve the purpose of controlling valve opening and closing. The surface of the sphere is welded to 13Cr or cemented carbide, which can meet the seal under very demanding conditions. The valve uses the top-mounted type, after the system pressure relief, may the online inspection and the maintenance, causes the maintenance to be simple. Reduce plant parking, reduce production costs.Ball Valve