Eccentric Butterfly Valve Stem Torque Calculator

Total stem torque: sealing friction + bearing friction + packing friction + static + dynamic torque

Input Parameters

[qM] Must Seal Pressure qM MPa

Disc Sealing Radius R mm

Seal Contact Width bM mm

Seal Friction Coefficient fM

Stem-Disc Eccentricity h mm

Disc Diameter D mm

Design Pressure P MPa

Bearing Friction Coefficient fC

Stem Diameter dF mm

Packing Factor ψ

Packing Width bT mm

Volume Flow Q m3/h

Pipe Flow Area A mm2

Closing Time t s

Dynamic Force Coefficient λα

Flow Resistance Coefficient ζα

Full-Open Resistance Coefficient ζ0

Full-Open Flow Velocity V0 mm/s

Dynamic Torque Coefficient μα

Static Water Torque Mj (0 if vertical stem) N·mm