Process Control

• According to the National Institute of Standards and Technology (NIST), process control is the active management of manufacturing processes based on the results of process monitoring. In the case of process control valves, the valve is actively managing a process based on the results of instruments such as charts or histograms.
  
  

Function

• Process control valves function in a variety of ways to control manufacturing processes, but all process control valves require some sort of actuator -- either hydraulic, pneumatic or electric -- to open the valve as part of the control valve assembly which also includes the positioner, air sets, transducer and limit sets. A signal is sent from the operator or process monitor to activate the actuator which opens the valve, allowing a measured amount of liquid or gas to escape, bringing the process back to equilibrium.
  
  

Applications

• Manufacturing processes that involve liquid, steam or chemical compounds can all be adjusted using a process control valve which can be configured using air-to-open, push-down-to-close or direct-acting assemblies.