Control Valve Study Bench

Teaching objectives

• Determination of the experimental KVS of the valve with and without positioner.


• Drawing and study of the curves.


• Intrinsic features of the valve.


• Qv = f(control) at constant head loss.

Feature of the installed valve :

• Qv and ΔP = f (control).


• Function of the positioner and phenomenon of hysteresis.

Functioning

• A pneumatic servomotor valve is
  supplied by the water network via a needle control valve. The flow is
  measured by a rotameter. A regulator allows to adjust the pressure of
  the network.


• The difference of pressure between the
  upstream and downstream of the control valve is measured with the help
  of a differential pressure transmitter with local display.


• The influence of the positioner on the
  answer of the valve is determined with the help of a current generator
  (4/20 mA) allowing the control of the control valve servomotor via an
  I/P converter (0,2 to 1 bar) or via a pneumatic electro-positioner.


• The device is mounted on a welded stainless steel frame, equipped of 4 adjustable feet.

Technical specifiations

• A regulator 0-3 bar of the water supply circuit with manometer.


• A needle flow adjusting valve made of stainless steel.


• A pneumatic needle control valve with variable Cv made of stainless steel.


• An electro-positioner.


• A regulator, with air oil separator and manometer.


• A differential pressure transmitter with local display and bleeding manifold.


• A rotameter (scale 60 to 600 l/h).


• An electrical cabinet, IP 55, including .


• A padlocked main switch.


• A ON light.


• An emergency stop button with key.


• A current generator (4/20 mA) with potentiometer and indicator.


• Control signal output by safety plugs.


• Technical manual in English

Essential requirements

• Power supply: 230 V, 50 Hz, 250 W


• Compressed air: 6 bar, 3 Nm3/h.


• Water: network clean water 3 bar, 20 °C, 1000 l/h.

Dimensions

• 850 x 425 x 940 mm