Valtek FlowTop General Service Valve FCD VLENIM8610A4 11/18
10
After these requirements are confirmed proceed with valve
maintenance.
WARNING
Crushing hazard ! Failure to keep
hands, hair, and clothing away
from all moving parts when operating the control valve can
cause serious injury.
1. Clear all dirt and / or foreign material from the plug
stem and control valve.
2. If leakage is detected, retighten the packing follower by
one full turn clockwise (See Table 7: Packing Adjust-
ment).
3. If retightening packing does not stop the leakage,
overhaul the control valve and replace the packing
(See Section 13: Disassembly and Reassembly).
4. If leakage is detected, retighten bonnet and flange
bolting.
5. Make sure all nuts and bolts are securely fastened.
6. If possible, stroke the valve and check for smooth,
full-stroke operation. Unsteady stem movement could
indicate an internal valve problem.
7. Make sure all accessory brackets and bolting are
securely fastened.
8. Check control valve health parameters:
• Characteristic curves of the valve with flow
• Upstream pressure
• Downstream pressure
into the control room.
NOTICE
Monitor trim and bonnet compo-
nents. If nominal and actual values
differ by more than 5%, maintenance may be required.
12 Troubleshooting
Contact customer service department or contract partner for any fault or defect found, otherwise
the manufacturer‘s guarantee shall be rendered null and void and the manufacturer released from
any responsibility. If the user performs the repairs, these User Instructions must be adhered to and
carried out in a competent manner. Original Equipment Manufacturer spare parts must be used to
make the repair.
Defect
No.
Possible Causes
Remedy
Stem does not move
1.1
• No auxiliary energy
supply (pneumatic air) to
actuator and accessories
(positioner, air filter regulator,
solenoid valve, limit switch, and/
or special accessories)
• Pneumatic actuators:
Check supply for leaks
Check air pressure (usually 87 psig; 6 bar)
1.2
• Mounted accessories do not work
• See User Instructions for accessory manufacturer
1.3
• Pneumatic actuator is defective
• Contact customer service department or contract
partner
1.4
• Excessive tightening of the pack-
ing box
• Loosen packing follower until valve operates
properly
NOTICE
Make sure there are no leaks.
1.5
• Valve trim worn or stuck
• Contact customer service department or contract
partner
Jerky stem movement
2.1
• Damaged stem
• Contact customer service department or contract
partner
