Flowserve XL Series High-Performance Positioner - Manual (Page 12)

45-12 Flowserve Corporation, Valtek Control Products, Tel. USA 801 489 8611
Troubleshooting XL Positioners
Failure Probable Cause Corrective Action
Valve won’t 1. Tubing to wrong ports 1. Re-tube to correct ports. (See ‘Installation’ section)
stroke, no 2. Cam action reversed 2. Refer to ‘Installation’ section and reverse cam
excessive air is 3. Lever is stuck 3. Work with lever arm until it turns freely
exhausting 4. Low air supply 4. Increase air supply to recommended value
from positioner 5. Relay tube stuck 5. Disassemble relay assembly and work relay tube free. Lightly
lubricate if necessary
6. Balance adjust screw not adjusted 6. Adjust balance pressure with adjusting screw
correctly
7. I/P module filter plugged 7. Remove I/P module and replace filter
8. I/P module failure 8. Replace I/P module
9. I/P mounting bolts loose 9. Tighten mounting bolts
10. I/P pressure signal blocked 10. Remove I/P module and clear passageway; replace O-ring if
necessary
Valve won’t 1. A diaphragm in relay assembly burst 1. Replace relay assembly or replace diaphragms
stroke, 2. One of the poppets is stuck 2. Remove relay assembly/poppet cover; free stuck poppet
excessive air 3. Internal control valve problem 3. Refer to instructions or check for actuator tubing leaks
exhausting 4. Damaged relay O-rings on relay tube 4. Disassemble relay and replace O-rings
from positioner 5. Blocked passageways in relay 5. Disassemble relay and check small holes under
diaphragms; clean if clogged
Actuator goes 1. Broken feedback spring 1. Replace feedback spring
to full signal 2. Linkage is disconnected or stuck 2. Check and tighten bolts/nuts in linkage. Make sure linkage
position does not hang up; grease pin that rides in follower arm slot
regardless of 3. Orifice is clogged by water, oil or 3. Remove orifice screw and carefully clean orifice hole
signal dust in air supply
4. Bent flapper, damaged nozzle 4. Straighten flapper or replace damaged parts
5. I/P module failure 5. Replace I/P module
6. Clogged orifice screen 6. Remove relay and clean or replace orifice screen
Calibration 1. Loose positioner mounting 1. Remove cover and check three screws holding positioner
shifts to bracket; check two bolts holding bracket to yoke
2. Loose linkage 2. Tighten nuts and bolts on linkage and stem clamp
3. Loose zero adjustment locking knobs 3. Tighten zero adjustment locking knob; re-calibrate if necessary
4. Wear of arms or pins 4. Replace worn arms, pins; grease appropriately
5. I/P mounting bolts loose 5. Tighten I/P mounting bolts
6. Stroke has changed in valve 6. Refer to valve maintenance instructions
Excessive air 1. Air leakage from manifold rings 1. Tighten screws holding relay assembly together and/or
consumption between relay and base replace O-rings
(other than 2. Air leakage from tubing 2. Tighten or replace tubing fittings
normal 3. Leaky cylinder piston O-rings 3. Replace O-rings in cylinder
exhaust) 4. Air leakage from relay 4. Disassemble relay and check and replace dynamic O-rings
next to tube if necessary
Actuator 1. Connection between signal capsule 1. Adjust gain according to Figure 8 or until actuator
strokes very and flapper misadjusted strokes approximately equal speed in both directions. Verify
slowly in one alignment of upper and lower gain plates. Make sure spacer
direction only nut is tightened
2. Tubing to cylinder is restricted 2. Inspect tubing/fittings for restrictions and replace if necessary
3. Balance pressure low 3. Adjust balance pressure according to page 5
Erratic 1. Dirt buildup on relay poppets or seats 1. Disassemble; clean poppets and seats; add air or change filter
operation 2. Dirt buildup on relay tube 2. Disassemble; clean relay and lightly lubricate; replace
O-rings if necessary; add air filter or change filter
3. Clogged ports / passageways in relay 3. Disassemble, inspect and clean all ports and passageways
4. Faulty I/P module 4. Replace the I/P module
5. Clogged orifice screw 5. Remove orifice screw and carefully clean orifice
6. Mechanical binding in linkage or 6. Tighten linkage or refer to valve maintenance instructions
internal galling in valve
7. Clogged orifice screen 7. Remove relay and clean or replace orifice screen
Excessive 1. Restricted air flow to positioner 1. Adjust air supply as needed
overshoot 2. Balance pressure not set correctly 2. Adjust balance pressure according to page 5.
3. Gain is set too high 3. Lower gain mechanism until overshoot is minimized