Flowserve PM15E Electro-Pneumatic Valve Positioner - Manual (Page 9)

D. Balance Arm
The balance arm can only be removed after I/P unit, diaphragm
and feedback spring have been removed. (See previous sections.)
Loosen the screws (3) and the balance arm can be removed.
When installing the balance arm make sure that the leaf spring (4)
on the underside of the balance arm (5) is properly engaged into
the groove (6) of the spool in the pilot valve.
Tighten the two screws (3) holding the balance arm to the
positioner.
E. Lower Arm
Once the front cover is removed, the lower arm can be easily
accessed. Remove the indicator, feedback spring and the cam.
Loosen screw (2) and remove twist stop (1). Remove screw (3),
lower arm (4), rod (5) and spring (6).
Check rod and lower arm for wear; replace if necessary. Clean the
rod and install it in the lower arm. The lower arm should move
easily and smoothly.
Install the lower arm and rod assembly into the positioner
housing, making sure that the spring (6) is attached properly to
the lower arm and positioner housing.
Secure the lower arm and rod assembly with the screw (3). Check
again that the lower arm moves smoothly.
Apply a small amount of grease on the small tongue on the lower
arm, then install and secure the twist stop.
Install cam, feedback spring, indicator and front cover.
F. O-Rings
With time and use, O-rings can become brittle. This can cause
poor operation and even failure of the positioner.
Always check O-rings when performing any work on the
positioner and replace bad O-rings.
A thin layer of silicon grease applied on the Buna N (Black)
O-rings prolongs their life. On Q (Red Silicon) O-rings, use a non-
silicon based grease.
G. Filter Plug
CAUTION: Do not operate the unit without filter and filter plug
installed. Do not attempt to unscrew filter plug while positioner
is pressurized.
The PM15E is equipped with a built-in secondary filter located on
the side of the I/P unit.
For replacement or inspection, make sure that positioner unit is
not pressurized, then unscrew filter plug (1). Remove filter (3)
and install a new one into the filter plug. Check condition of O-ring
(2) and filter compartment. If moisture is found, check upstream
filters/oil-water separators. Moisture can cause I/P failure.
Reinstall filter plug.
Flow Control Division
Worcester Controls
WCAIM2017 Model PM15E Electro-Pneumatic Valve Positioner 9
3
4
5
6
2 1 5
6
3
4
1
2
3