Control Valve Study Bench

Control Valve Study Bench

Teaching Objectives of

• 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