GE Baker Hughes Masoneilan SVI FF Installation And Operation Manual page 51

2. Bolt the extension shaft to the valve position take-off shaft using a 1⁄4 - 28 UNF socket
flathead screw. Secure the machine screw holding the extension shaft with a torque of
144 in-lbs (16.269 N-m).
Upon internal valve pressure the thrust shaft is pushed out to the mechanical stops,
usually a thrust bearing. On valves where the valve position take-off is mounted directly
on the end of the plug shaft, a Camflex for example, the shaft must be bearing on its stop
to properly set up the SVI FF digital valve positioner. During hydrostatic testing the shaft is
thrust to its stop and a normally tightened packing retains it in that position.
On vacuum service, the valve shaft can be drawn into the body by the vacuum acting on
the shaft, but the magnetic coupling must be assembled flush with the mounting bracket
with the shaft pulled fully out to its thrust bearing.
3. Ensure that the end play from the vacuum position to the fully extended position is less
than 0.06 in. (1.524 mm).
4. Slide the magnet holder into the extension shaft. The location of the magnets is in the ring
of the magnet holder. The magnetic axis is the imaginary line through the center of both
magnets.
5. Rotate the magnet holder so that the magnet axis is vertical when the valve is in the
closed position. See Figure 19 on page 50 and Figure 20.
6. Align the end of the magnet holder flush with the end of the mounting bracket. Secure the
magnet holder with two M6 set screws.
7. Slide the V-Seal over the magnet holder.
8. Secure the SVI FF onto the mounting bracket using four M6 x 20 mm Socket Head Cap
screws.
© 2019 Baker Hughes, a GE company, LLC. All rights reserved.
Air-to-close (ATC)
Set magnet when actuator is
energized
Magnet axis
Long end of bracket to left
Figure 20 Mounting Bracket on Air-to-Close Actuator
Magnet
axis
Masoneilan SVI FF Instruction Manual
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