This paper introduces the classification of ball valve and ball valve of the advantages and disadvantages of various types, focusing on large-diameter ball valve types and applications, as well as my subject DN500 large diameter natural gas ball valve of the applicable valve type. Including how the selection, calculation. According to GB150-1998, "Design and Simulation valve", "ball valve design and selection", "Valve Design Manual", "Practical Design Manual Valves", "Mechanical Design Manual" in the contents and formula, I chose make two side-mounted ball valve. This article has done a series of calculations on the ball. Describes the calculation of body thickness, two-way ball valve stem seal fixed torque and strength checking, double-seat two-way ball valve seal sealing surface of the fixed and the calculation of total force than the pressure on the ball of the valve seat ring Calculation of friction torque, the inlet valve seat ring on the ball of the friction torque terms, the import side of the ball valve seat ring friction torque terms, the export side of the ball valve seat seal the calculation of the friction torque, valve seat seal circle on the sphere of the friction torque, bearing friction torque calculation of thrust pad friction torque, friction torque and valve packing and O-ring and the friction between the valve stem, two-way ball valve stem seals switch to a fixed moment, stem strength calculation
苦瓜老太婆
