Sabtu, 26 Mei 2012

control valve

control valve

Control Valve is one of the final control element in an automatic process control, and therefore a very important role in carrying out functions in the control loop. Its function is to set / change the control variable that changed the price flownya (flow). Control valve is an important part in the process line, the control valve is often defined as "Continuously Variable Orifice" in a process line.

Last element of the control circuit is an instrument that can directly affect and change the process variable. Form the final control element is : 
  • Control Valve 
  • damper 
  • Governor Valve 
  • Variable Speed ​​Pump 
  • etc.
how to choose a good control valve?
Aspects that must be considered in selecting the control valve are: Matters relating to operating condition (corrosion, abrasion, noise, temperature, pressure difference, fluid type: gas, liquid, vapor). Relationship with the valve changes the flow characteristics, including characteristics and process control loop. The shape and size of the valve installation and construction aspects.
Model - model valve body is a lot of use:
  • Single Port Valve body 
  • Double Port Valve body 
  • Three Way Valve body 
  • Butterfly Valve body 
  • V-Notch Ball Control Valve body 
Control valves are usually equipped with:
  • Hand Wheel 
  • limit Stop 
  • booster 
  • positioner 
  • solenoid Valve 
  • tranducer 
  • limit Switch 

whether the function control valve handwheel?
Is one of the essential equipment for the control valve can be used in the event of "Water Supply Failure" or there is damage / leaks in the actuator. Sometimes used in an important service at start up. There are two types of Hand Wheel : 
  • Side Mounted 
  • Top Mounted Hand Wheel Operator 
whether the function of the control valve limit stop?
Stop Limit fitted to the needs of stroke when the valve is only limited to a particular opening, which limit their use depending on the needs of the stop will be installed on the "Air to Open" or "Air to Closed".

whether the function of the control valve Volume Booster ?
Volume is basically
Pneumatic Booster Relay High Capacity (Pneumatic Relay large capacity), created to raise the Actuator Operating Speed ​​in order to prevent delay time (Time Lag). Volume Booster is used when a pneumatic signal from the controller sent very far away or the capacity of the diaphragm actuator.