11
Operational Check
Before beginning steady operation, perform an operational check by following the steps
outlined below:
1. Close the shut-off valves on the CV-COS inlets and outlets. Check operation without
yet starting the flow of steam.
2. Check to make sure the designated air pressure is being supplied to the pneumatic
positioner. (Air pressure: 0.38 MPaG (54 psig))
NOTE: If the air supply pressure is incorrect, adjust it using an inlet air reducing valve.
NOTE: If an air reducing valve is attached, check the reading on its pressure gauge.
3. Turn on the power to the controller operation signal source, etc. (referred to
hereinafter as the controller).
4. Set the operation signal output from the controller to the CV-COS to 0% (4 mA).
5. Check the CV-COS valve travel and the actuator air supply pressure.
Valve Travel: Fully closed (valve travel 0%)
Air Pressure: 0 MPaG (check the pressure gauge on the pneumatic positioner for the
air pressure)
NOTE: If the air pressure is not 0 MPaG (0 psig), refer to the "Adjusting the Zero/
Span" section of this product Instruction Manual and adjust the zero.
6. Set the controller operation signal to 100% (20 mA).
7. Check the CV-COS valve travel and the actuator air supply pressure.
Valve Travel: Fully open (valve travel 100%)
Air Pressure: Approximately 0.38 MPaG (54 psig) (check the pressure gauge on the
pneumatic positioner for the air pressure)
NOTE: If the valve travel differs widely from 100%, refer to the "Adjusting the Zero/
Span" section of this product Instruction Manual and re-adjust the span and
the zero.
NOTE: If the control valve does not move from the fully closed position, check to see
if the wires for the controller and control valve have any breaks, a short-
circuits, or have their polarity reversed (+ and – are reversed).
8. Set the controller operation signal to 50% (12 mA).
9. Make sure valve travel is smooth and without vibration.
NOTE: If the valve is vibrating vertically, it may be being caused by noise on the
signal wiring. Check to see if there is a possible source of noise nearby.
Valve Travel
Gauge
Actuator Air Supply
Pressure
Positioner Air Supply
Pressure Gauge
172-65443A-01 (CV-COS) 17 Nov 2014
