Instruction Manual
D103363X012
26000 Valve
June 2017
6
20. Attach the actuator to the bonnet. Turn the actuator to thread the actuator stem onto the valve stem until the yoke
touches the shoulder of the bonnet.
21. Lock the drive nut (key 9), see figures 3, 2, and 4.
22. Apply 4 to 5 psi to the actuator for air-to-open or 13 to 14 psi for air-to-close.
23. With 50 psi air applied to port A, counter tighten the jam nuts (key 27) and slowly turn the valve plug and stem
assembly (key 4)
clockwise to thread it into the actuator stem. Stop and lock the stem with the jam nut (key 27)
when port B shows some minimum flow.
24. Adjust the zero position of the travel indicator to the present position of the travel indicator disk (key 58).
25. Reduce air pressure to 3 psi for air-to-open or increase air pressure to 15 psi for air-to-close. For Cv < 1.0, there
should be no seat leakage (Class VI). For Cv > 1.0, the allowed leakage is Class IV. If leakage is noted, loosen the jam
nuts (key 27) and turn the plug and stem assembly (key 4) further into the valve bonnet (key 8).
26. At the lowest actuator travel position, the indicator disk (key 58) shall be at least 0.040 inches below the zero travel
position. If not, move the stem (key 4) further into the bonnet (key 8) and recalibrate the travel indicator.
27. Check the valve travel for a full 1/2 inch from the zero point on the indicator scale.
28. Check the dead band of the actuator. The difference between the signal to move the stem up and the signal to
move stem down shall not exceed 2 psi. If it does exceed 2 psi, the secondary packing (key 14)
is too tight.
29. See appropriate actuator instructions to set the travel stops. (Refer to illustrations in the appropriate actuator
instruction manual to determine what type of stops are being used).
30. Attach and calibrate the positioner.
Note
Travel should commence from the zero travel indicator mark at 3.2 psi (4.3 mA) air-to-open or at 14.8 psi (19.7 mA) air-to-close.
The flow should enter only through the lower port A to help energize the V-ring packing set (key 17).
