Where: f friction coefficient, for PTFE seal ring, f=0.5, the friction torque of the valve stem in the packing depends on the sealing form and working pressure. When pressed, the upper and lower seal rings bear uniform pressure, and the friction in the packing does not depend on the rotation angle of the ball. Therefore, the friction torque of the packing is as follows: where: df valve stem diameter; H1 Contact height between single ring packing and valve rod; The friction torque of Z1 packing ring number valve stem head can be expressed in the following formula: where: the calculated diameters of dF and dFT valve stem heads can be seen from the above, and the opening and closing torque of pneumatic ball valves is determined by many aspects. For pneumatic ball valves with a diameter of 100mm and a pressure within 1.6MPa, the opening and closing torque cannot exceed 60N-M. From the above analysis, it can be seen that the floating pneumatic ball valve has its limitations. Due to structural reasons, the torque will increase exponentially under large diameter and high pressure. Therefore, it is necessary to select the pneumatic ball valve with fixed structure, and we will further explore its applicability.

According to pressure, it can be divided into high-pressure ball valve and low-pressure ball valve
High pressure pneumatic ball valve: mainly used in oil, natural gas, hydraulic oil, construction machinery and other industries
Low pressure pneumatic ball valve: mainly used in corrosive pipelines with water as the medium!