Emerson Clarkson series Instructions Manual page 15

Clarkson SerieS KGF and KGF-HP Slurry valveS
InstallatIon and maIntenance InstructIons
7. inspect the gate for sharp edges or
excessive damage. Some scoring will
occur in normal use. if the gate has been
bent beyond " permanent deflection at the
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center, straighten or replace.
if straightening is performed, use
considerable care to minimize marks on
gate surface. Scores or other distress
marks may be cleaned up with a belt
sander. Machining the gate surface is not
recommended. light scale buildup may
be removed with a putty knife or gasket
scraper. inspect the gate for wear and
roughness. use a disc grinder or belt sander
to remove rough surfaces. Take particular
care on the leading and beveled edge to
remove burrs and other sharp edges.
8. examine frame for signs of corrosion,
damage or other potential problems.
9. Check all bolting hardware for thread
integrity, signs of corrosion, straightness,
etc. replace as required.
10. For valves with purge control assemblies,
examine major components, look for signs
of corrosion and material build-up. Clean
any visible build-up, replace if necessary.
examine gasket and replace if necessary.
11. examine actuator assembly.
a) Manual valves: check stem for
corrosion, straightness, etc. look for
signs of wear on brass stem nut.
B) air or hydraulic: check for seal leaks
around cylinder rod seal, heads and
caps. examine cylinder rod for signs of
corrosion, straightness, etc. Service per
manufacturer's instructions.
C) electric motor: service per
manufacturer's instructions.
reassembly
1. lay the first housing half face down on a
suitable flat surface.
2. replace gate supports if required, refer
to Section 10 Gate support replacement;
supports should be replaced as a set and
are recommended for replacement if
sleeves are replaced.
3. Carefully lay two new housing gaskets
on face of housings. Gaskets may be
held in place with a small amount of
silicone lubricant placed between gasket
and housing.
4. Take second housing and place into position
on the first housing, and properly align bolt
holes making gaskets remain in place.
5. insert most of the housing bolts, leaving
out the top bolts that are used to hold
the actuator assembly to the housing
and loosely tighten. Tap the edges of the
housings to align the internal sleeve bores
to within ", at the same time maintaining
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bolt hole alignment in the square flanges.
6. install new sleeves and retainer flanges
(if used) per instruction in Section 'Sleeve
replacement'.
7. lift the valve assembly to vertical position.
refer to lifting, Section 17.
8. using dOW iii or approved alternate,
completely fill all internal cavities of the
new secondary seal.
9. Paying attention to the top and bottom of the
secondary seal, insert the new lubricated
secondary seal into the valve housing
assembly. (The bottom of the seal has
radiused edges.)
10. Place the secondary seal retainer plate
into position.
11. replace and hand tighten all the retainer
plate fasteners and lockwashers.
12. apply a small amount of recommended
lubricant to the two tapered faces of the
'sharp end' of the gate.
13. Press the gate firmly through the secondary
seal into the valve housing assembly until
the mark drawn on the gate reaches the
top of the retainer plate or gate reaches
previously recorded dimension.
14. Fully tighten all the retainer fasteners.
15. reinstall the actuator / frame assembly
with the housing / frame fasteners loosely.
16. reconnect the gate to the actuator. (in order
to facilitate installation and future removal,
a coating or anti-seize compound should be
applied to the outside of the clevis pin over
the yoke contact area.)
17. 'Stretch' the frame / actuator assembly
with respect to the housing by pulling (not
lifting) the frame / actuator assembly to
its maximum movement away from the
housing assembly (holding housing in place
if valve is removed from pipeline). Tighten
the frame / housing bolts and verify the
tightness of the actuator to frame bolts.
18. Cycle valve to full open position and check
the gate position.
19. rattle the gate. it should be mostly
disengaged from the sleeves. The outboard
edges of the gate should be free and the
center still partially engaged in between
the sleeves.
20. Cycle gate full closed and full open.
21. inspect gate for pieces of rubber. if
significant amount of rubber is present, a
sharp edge(s) on the gate may be causing
seal damage or the gate is extending too
far on the up stroke. The ends of the gate
should be free and the center still engaged.
if the sleeve / gate is misaligned, loosen the
frame actuator bolts and/or adjust the yoke
until the proper position, open and closed,
is obtained.
22. reinstall the valve, refer to
Section 17 lifting.
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