Swagelok offers a range of accessories to enhance instrumentation and process ball valve performance and control, including pneumatic actuators, solenoid valves, limit switches, and position sensors.
- Pneumatic actuators are available in both our standard 130 and 150 series rack and pinion models and in our ISO 5211-compliant models.
- Solenoid valves attach to the actuator to create an electropneumatically actuated assembly.
- Limit switches indicate actuator position by means of an electrical signal.
- Position sensors provide visual status of a valve.
Valve Operating Torque
- Start (break) torque is the torque required to begin actuation of a valve. The actuator start torque must be greater than the valve start torque.
- End (run) torque is the torque required to complete the actuation. The actuator end torque must be greater than the valve end torque.
Factors that Affect Operating Torque
- Frequency of Use -Operating torque typically increases as the time interval between cycles increases.
- Cycle Wear - Contacting surfaces valve ball, seat, and body, for example - gradually wear as valves are actuated repeatedly, resulting in increased friction and operating torque. Actuation speed may influence the rate of valve wear as well.
- Seat or Packing Material - In some ball valve designs, friction between ball and seat or packing affects operating torque, which varies with material and lubricant.
- System Pressure - Higher pressures cause greater contact forces and friction, resulting in higher operating torque.
- System Temperature - Lower or higher temperatures, depending on the valve design, can cause increased operating torque.
- System Media - Different system fluids have varying viscosities, bringing about different levels of friction and affecting operating torque. Some lightweight oils may reduce operating torque. Dirty, abrasive, or highly viscous fluids may increase operating torque.
Factory assemblies and kits for field assembly are available.