17
YT-3400/3450 series
6. Insert connection bar into the feedback lever. The bar should be inserted when the
actuator clamp is at 50% of the total valve stroke.
Fig. 16:
Proper way to connect feedback lever, connection bar, and lever spring by connecting pneumatic
pressure to actuator to position the valve at 50%
7. Check if feedback lever is vertical to the valve stem at 50% of the valve stroke. If it is
not vertical, adjust the bracket or the connection link bar to make vertical. Improper
installation may cause poor linearity and may create unnecessary hunting during the
operation.
Fig. 17:
Feedback lever and valve stem
8. Check the valve stroke. The stroke numbers are engraved on the feedback lever of the
positioner. Position the connection bar at the number on the feedback lever which
corresponds with the desired valve stroke. To adjust, move the bracket, the connection
bar or both.
Stroke : 30mm
Stroke : 70mm
Fig. 18:
Feedback lever and location of the connection bar