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9
Refurbishment
Refer to the health and safety (see section 2) before starting any refurbishment work.
Never remove or perform maintenance on a valve or flange joint unless the line has
been fully depressurised, drained and where necessary, purged of toxic, explosive,
or flammable media.
9.1
Disassembly
a) Set the valve in open position (wrench / stem flats in line with the pipeline) to
prevent the ball protruding out of the body and fouling on the body
connectors when the body is removed.
b) The body connectors must be pulled apart slightly to prevent scoring of the
machined faces. The fire-safe valves, the connectors must be pulled apart
even further to allow clearance for the body seal spigot.
c) Extract all the body bolts and slide the body completely from the two body
connectors. Take care not to damage the connector sealing faces.
d) Remove and discard the seats and body seals.
e) Close the valve and using a soft drift, tap out the ball.
f) To dismantle the stem assembly, remove:
Wrench assembly (if fitted)
Gland nut locking clip
Gland nut
Belleville washers
Gland
g) Remove the stem through the body. For DN 15 valves, remove the gland
packing and align the stem wrench flats across the valves to facilitate stem
removal. The gland packing and thrust seal can now be removed, taking
care not to damage the sealing faces.
h) All components not replaced by parts in the repair kit should be thoroughly
cleaned and stored in a clean, secure area.
i)
All sealing faces on the body, insert and ball must be checked for corrosion,
erosion and scratches. If damage is found or there is any reason to believe
that a part is damaged, replace the part.
j)
Valve parts should be cleaned using a suitable degreasing agent. Hard
deposits can be removed using stainless steel wire wool. Care should be
taken to avoid damaging sealing faces.
9.2
Reassembly
a) Ensure that the repair kit and/or spare parts are suitable for the valve being
refurbished.
b) Cleanliness is essential for long valve life. The seats may be lightly lubricated with
a light oil to aid bedding in. Ensure that the lubricant is compatible with the
pipeline media, and the pressure and temperature of the application.
c) Fit a new thrust seal on the stem (see section 11) and insert the stem through the
valve body from inside the valve cavity. Tweezers may make it easier to do so on
DN 15 valves.
All manuals and user guides at all-guides.com
Worcester 13 / 14 Series User Instruction – WCENIM0002-01
Page 9 of 13
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