First you should calculate the total torque adding the 3 torque values.
1)Seal friction torque:- This depends on the Torque due to the friction between the Disc seal & the inner dia. of body.
2)Bearing Friction Torque:- The torque exerted due to the bearings inside the shaft bore.it depends on the shaft dia.& the bearing friction coeff.
3)Hydrodynamic Torque:- The torque due to the load on the Disc by the Media.Due to opening & closing of Disc.
After the Torque value is determined you have to multiply the torque by a safety factor of 1.3 to 1.5 to select the operator.
The details you have given is not clear but I guess you may select a rubber seated butterfly valve with a rated pressure of 5-10 bars.

MORE NEWS