Gate valves are normally torque-seated when closing, so torquing out at the closed seat is correct. Torquing out mid-stroke, or before the open limit, means something is binding: a stuck wedge, debris, a dry stem nut or a seized packing. Techs read the event history on the actuator and then handwheel the valve to feel where it hangs up.
Valve torqued out at 70 percent open, actuator's fine, I think the stem nut's dry and galling.
Also heard as
- torqued out
- torque trip
Related terms
MOV
Motor-operated valve: a valve driven by an electric actuator with a motor, gearbox, torque switch and limit switches.
Galling
Severe adhesive wear where loaded metal surfaces slide, cold-weld together and tear material out.
Stroke
To run an automated valve through its full travel to prove it moves, seats and reports position correctly.
Wedge
The tapered closure member of a gate valve that is driven down between two inclined seats to seal.