GE Baker Hughes Masoneilan SVI FF Installation And Operation Manual page 121

Problem
The valve's full stroke is
insufficient for the setpoint
input (An accumulated
value of 100% travel = 1
stroke. The travel does
not need to occur in one
movement.):
The steady state deviation
between the setpoint and
readback position exceeds
specifications.
The valve oscillates
cyclically (limit cycle).
© 2019 Baker Hughes, a GE company, LLC. All rights reserved.
Table 25 Troubleshooting Valve Control (Continued)
Presumed Cause
The air supply pressure is not
high enough to drive the valve
actuator.
The range of the setpoint is lim-
ited by software.
The tight-shut or full-open
action is active.
The tuning has not been per-
formed correctly.
Tuning is incorrect.
The friction of packing is large.
There's an air leak from the out-
put pressure pipe, or the feed-
back lever is not correctly
attached.
Process condition is unstable.
Lever/linkage connection prob-
lem.
Remedy
Check the air supply pres-
sure rating for the valve
actuator and supply air at
the correct pressure, and
redo Find Stops and the
redo Auto Tuning.
Change the position limits.
Check the values of
FINAL_VALUE_CUTOFF_HI
and FINAL_VALUE_CUT-
OFF_LO.
Redo tuning to perform 0 &
100% point adjustment.
Run tuning.
1)Repair packing.
2. Redo auto tuning.
Check the piping and
attachment of the lever, and
redo Auto Tuning.
Review the process set-
point/tuning.
Verify linkage operation.
Masoneilan SVI FF Instruction Manual
See Section
"Connecting
the Tubing and
Air Supply" on
page 62
"Quick Start"
on page 31.
"Transducer Block
Parameters" on
page 149
"Transducer Block
Parameters" on
page 149
"Quick Start" on
page 31
1. Contact manu-
facturer.
2. "Quick Start" on
page 31.
"Installation"
on page 44
"Quick Start"
on page 31.
"Quick Start" on
page 31..
"Installation" on
page 44.
| 121
=