Flowserve Valtek Mark 10 Survivor Control Valves - Manual (Page 12)

Valtek Mark 10 Survivor Control Valves FCD VLENIM0036-05 – 07/09
12
At least once every six months, check for proper operation by following the preventive maintenance
steps outlined below. These steps can be performed while the valve is in-line and, in some cases,
without interrupting service. If an internal problem is suspected, refer to the “Valve Disassembly and
Reassembly” section.
4.1. Look for signs of gasket leakage through the end flanges and bonnet. Tighten flange and
bonnet bolting (if required). See Table II.
4.2. Examine the valve for damage caused by corrosive fumes or process drippings.
4.3. Clean valve and repaint areas of severe oxidation.
4.4. Check packing box bolting for proper tightness. Tighten only as necessary to prevent stem
leakage. Use caution to not overtighten the packing. If leakage cannot be stopped, consult
factory.
CAUTION:
a
Do not overtighten packing. This can cause excessive packing wear and high stem
friction that may impede stem movement.
4.5. If the valve is supplied with a lubricator, check the lubricant supply and add lubricant if
necessary. See Table I for suggested lubricants.
4.6. If possible, stroke the valve and check for smooth, full-stroke operation. Unsteady stem
movement could indicate an internal valve problem.
NOTE: Smooth operation can be best maintained using packing lubrication and high performance
positioners. Contact the factory for special instructions if stroking the valve produces jerky motion.
WARNING:
c
Keep hands, hair, clothing, etc. away from all moving parts when operating the valve.
Failure to do so can cause serious injury.
4.7. Make sure positioner linkage and stem clamp are securely fastened. If the stem clamp is
loose, check plug thread engagement (refer to the “Reassembling the Actuator” section for
the correct procedure on aligning the plug with the seat).
4
Valve Maintenance