Instruction Manual
D101728X012
3710 and 3720 Positioners
September 2017
18
stud location vertically so that the feedback lever is perpendicular to the stem. Tighten the hex nut attached to the
drive stud.
the appropriate travel mark on the feedback lever.
17. Tighten the cap screws to secure the drive stud bracket to the stem bracket. If necessary, readjust the drive stud
position to keep the feedback lever perpendicular to the stem.
18. Make the output, supply, instrument, and vent connections as described in the Connection section. Calibrate the
positioner by performing the procedures in the Calibration section.
19. Replace the actuator front and back yoke covers. Discard the actuator blanking plate and four screws.
Figure 10. Mounting Plate Positioned on Actuator
W8461
Figure 11. Positioning Drive Stud in Feedback Lever
FEEDBACK LEVER
(KEY 94)
DRIVE STUD
AND ROLLER BEARING
Connections
WARNING
The positioner is capable of providing full supply pressure to connected equipment. To avoid personal injury and
equipment damage, make sure the supply pressure never exceeds the maximum safe working pressure of any connected
equipment.
CAUTION
Do not use sealing tape on pneumatic connections. This instrument contains small passages that may become obstructed
by detached sealing tape. Thread sealant paste should be used to seal and lubricate pneumatic threaded connections.
To complete the installation of a positioner, connect tubing and fittings between the positioner and the actuator. The
fittings, tubing, and mounting parts required depend on the type number and optional equipment such as filter,
regulator, and bypass valve.
Positioner pressure and electrical connection locations are shown in figure 12. All pressure connections are 1/4 NPT
internal. Use 3/8‐inch tubing or 1/4 NPT pipe for all tubing connections.