Valve Maintenance - Flowserve Valtek Mark 100 User Instructions

Valtek ® Control Products Mark 100
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Valve
maintenance
At least once every six months, check for proper operation by
following the preventative 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.
1. Look for signs of gasket leakage through the end flanges
and bonnet. Retorque flange and bonnet bolting (if
required). See Table 2.
2. Check for fluid leakage to the atmosphere through the body
drain plug, if applicable.
3. Examine the valve for damage caused by corrosive fumes
or process drippings.
4. Clean valve and repaint areas of severe oxidation.
5. Check packing box bolting for proper tightness. Refer to the
packing installation manual for specific details on main-
taining the style of packing supplied.
a CAUTION: Do not overtighten packing. This can cause
excessive packing wear and high stem friction that may
impede stem movement.
6. If the valve is supplied with a lubricator fitting, check
lubricant supply and add lubricant if necessary. See Table 3
for common lubricants.
7. If possible, stroke the valve and check for smooth, full-
stroke operation. Unsteady stem movement could indicate
an internal valve problem.
NOTE: Due to excessive friction, graphite packing can
cause the plug stem to move in a slip/stick fashion.
VAIOM000103-02 (EN/AQ) March 2020
and Mark 100SC Control Valves
™
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WARNING: Keep hands, hair and clothing away from all
moving parts when operating the valve. Failure to do so
can cause serious injury.
8. 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.) Tighten stem clamp nut.
9. Ensure all accessories, brackets and bolting are securely
fastened.
10. If possible, remove air supply and observe actuator for
correct fail-safe action.
11. Check rubber actuator bellows for splits, cuts or wear.
12. Spray a soap solution around the cylinder actuator retaining
ring, adjusting screw and actuator stem guide to check
for air leaks through the O-rings.
13. Clean any dirt and other foreign material from the plug stem.
14. If an air filter is supplied, check and replace cartridge
if necessary.
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