Flowserve PMV D20, Installation Operation & Maintenance

18

For mounting, proceed as follows:

Mounting the Follower Arm

 (Figures 3

and 6)
1. Unscrew the lock nut for the follower
arm attachment.
2. Place the follower arm on the shaft at
the back of the positioner and fasten it with
the lock nut. The follower pin should point
back from the positioner.

CAUTION:

 Maximum torque

0,25 Nm (0,18 ft-lbs).

Mounting the stem clamp bracket and
take-off arm (Figure 3)

1. Attach the stem clamp bracket to the
stem clamp and fasten it with two hexa-
gon socket screws and lock washers.

2. Attach the take off arm to the stem clamp
bracket and fasten it with a hexagon
socket capscrew and a washer. Ensure
the take-off arm slot is centered.

Mounting the positioner (Figure 3)

1. Adjust the actuator to mid-stroke.

2. Pre-assemble the mounting bracket on
the left actuator
leg hand-tight with two U-bolts, nuts and
lockwashers.

3. Attach the positioner to the pre-
assembled mounting bracket and fasten
it with two hexagon head screws  and two
lock washers. Check that the follower pin
is inserted in the slot of the take-off arm
and the follower arm is positioned at a right
angle to the outer edge of the positioner.

4. Tighten all screws and nuts.

NOTE:

  A  slight unsymmetrical

mounting increases the linearity
deviation but does not affect the
performance of the device.
Depending on the  actuator size
and stroke it may be necessary to
flip the take-off arm (Figure 3) by
180

°

 and attach it to the opposite

side of the stem clamp bracket.

Follower pin adjustment (Figure 4)

The positioner follower pin must be
adjusted to match the valve stroke in the
following manner:

1. Adjust the follower pin ( 10
mm) as indicated on the follower arm’s
embossed scale (Figure 6).

2. Exhaust the actuator.

3. Loosen the follower pin and shift it along
the follower arm until the control marking
on the feedback gear (Figure 4) is hori-
zontal (points to the center of the feed-
back potentiometer). Fasten the follower
pin in this position.

4. Adjust the actuator to full stroke and
check the follower pin adjustment the
same way as described in step 3. As the
actuator strokes, the rotation of the feed-
back gear should be between the inner
control markings. If the length of rotation
is outside the control markings, adjust the