Why plug valves need special attention
Plug valves often use metal-to-metal seats and have higher bearing friction due to sealing geometry. This means torque can rise sharply, so bearings and stems must be sized conservatively.
Stem & bearing checks
Calculate shear and torsion on stems, and bearing contact pressure based on expected radial and axial loads. For high-cycle applications, check bearing fatigue life.
Seat contact & torque
Model the seat contact pressure using the plug taper angle and material properties. From contact pressure and friction coefficient, estimate breakout and running torque.
Deliverables & recommendations
- Stem & bearing sizing worksheet
- Torque envelope for actuator selection
- Seat contact pressure validation