DeZurik P42 Instrukcja - Strona 9

Przeglądaj online lub pobierz pdf Instrukcja dla Pozycjonery zaworów DeZurik P42. DeZurik P42 11 stron. Pmv positioners

Reversing Valve Action

To change from having the valve Open, to having it Close, on an increasing signal, follow the steps

below:

1. Close the valve. (Failure to close the valve may result in the valve slamming shut.)

2. Relieve supply air pressure.

3. Reverse the cylinder tubing connections at positioner ports C1 and C2.

4. Remove the four screws that fasten the positioner cover to the positioner, and remove the

cover.

5. Note the position of the indicator, then remove the indicator screw and indicator.

6. Note the cam range being used, then remove the nut and cam.

7. Invert the cam and install it on the input shaft.

Note: Thread the nut loosely.

8. Connect the air supply.

9. Set the positioner input signal at the minimum value of its range, for example, 4mA for a 4–

20mA range.

10. Position the cam as shown in the right side of Figure 3.

Note: Ensure the ball bearing does not ride up on the inactive portion of the cam.

11. Tighten the cam nut.

Note: The cam will turn slightly with the nut as it is tightened. Turn the cam slightly counterclockwise

before tightening the nut, to allow for this.

12. Install the position indicator and the positioner cover.

August 2012

Figure 3 – Cam Position

Page 9

DeZURIK

D10112