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Top Entry ball valve

Design code

Design standards: ISO 17292,API 6D,GB/T 12237,API 607,API 6FA
Structure length: GB/T 12221,API 6D,ASME B 16.10
Connection standard: ASME B16.5,ASME B16.47,GB/T 9113,HG/T 20592
Test and inspection: API 598,ISO 5208,GB/T 13927
Pressure-temperature: ASME B16.34,GB/T 12224

  • Product Profile

    The Top Entry ball valve is simple and quick to remove on the pipeline and easy to maintain. When the valve fails on the pipeline to be repaired, it is not necessary to remove the valve from the pipeline, only remove the middle flange bolts and nuts, remove the bonnet and stem assembly from the valve body, and then remove the ball and seat assembly. The sphere and valve seat can be repaired online. This maintenance saves time and minimizes losses in production.


  • Design Feature

    Top type ball valve is divided into floating ball valve and fixed ball valve.


    Installed floating ball valve nominal size ≤ DN100. A compression spring is applied on the ball, and the function of the compression spring is to apply a pre-tightening force on the ball, so that the sealing surface of the seat is in close contact under any circumstances, and the sealing performance is good. The wedge Angle between the valve seat and the valve body contact surface is 10°, the valve seat can self-lock, in the direction of the pipeline, when the valve seat is subjected to greater pressure, the valve seat will not produce any displacement. 


    Therefore, the valve of this structure has both the characteristics of gate valves and the advantages of ball valves. In the maintenance inspection, it was found that the valve body and the seat are prone to leakage, and if the preload force of the spring is increased, the closing torque of the ball valve is bound to be increased. In order not to increase the closing torque of the ball valve, a rubber O-ring is added on the back of the seat sealing surface to solve the leakage problem on the back of the seat sealing surface.


    The disadvantage of the mounted fixed ball valve is that the spring preload force can not be adjusted and controlled, and the spring compression is large when assembling, and the assembly is difficult. To solve this problem, the spring material is used INCONEL X-750 or INCONEL X-718. In addition, the spring seat and adjusting nut are added, the outer circle of the seat and the spring seat are turned respectively, and the adjusting nut is used to press the spring into the spring seat, and the seat assembly is installed in the valve body.


    Because the spring is compressed before the ball is installed, it is convenient to install the ball. When the ball is assembled, the adjusting nut is withdrawn from the spring seat, and the pre-tightening force of the spring on the ball is small. If you want to increase the preload, you can adjust the adjusting nut.


  • Data download