Valve Maintenance; Figure 2 - Pressure Balanced Mark One Control - Flowserve Valtek Mark Two User Instructions

5 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 Section 6, Valve Disassembly and Inspection.
5.1 Look for signs of gasket leakage through the end flanges
and bonnet. Re-torque flange and bonnet bolting (if
required). Refer to Table II for bonnet bolt torque values.
5.2 Examine the valve for damage caused by corrosive fumes
or process drippings.
5.3 Clean valve and repaint areas of severe oxidation.
5.4 Check packing box bolting for proper tightness and pack-
ing leakage. If packing leakage is noticed, packing mainte-
nance is required. Refer to the packing installation manual
(document number VLAIM040) for specific details on
maintaining the style of packing supplied.
6
Valtek Mark One and Mark Two Control Valves FCD VLENIM0001-02-A4 - 05/16
Figure 2: Pressure Balanced Mark One Control Valve Body Assembly
a
CAUTION: Do not overtighten packing. This can cause
excessive packing wear and high stem friction that may
impede stem movement. Packing that is tightened too tight
will typically not seal correctly.
5.5 If the valve is supplied with a lubricator fitting, check lubricant
supply and add lubricant if necessary. See Table I for
common lubricants.
5.6 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 a dry graphite packing can
cause the plug stem to move in a jerky fashion. Lubrication
of graphite packing will provide smoother stroking.
Lubrication can be done by using a bonnet lubricator or by
liberally coating each packing ring by hand during installation.
Please refer to Table I for lists of common lubricants.
*Optional angle body