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WNCO Valve's WN-1 Valves
Service & Maintenance
WNCO Valve's kelly valves are design
engineered and manufactured to provide maximum life and minimum
maintenance. At the heart of every WNCO Valve is the new WN-1 seal system.
The double backup ring arrangement evenly distributes the sealing load for
a more positive seal, resulting in longer o-ring life, reducing
maintenance and increased reliability. This extra back-up protection,
combined with tough, smooth Teflon seals between the ball valve and seat,
provides the maximum resistance to corrosion and abrasion.
Types Of Repairs:
SEALS AND RINGS: Replacement of o-rings, backup rings, Teflon seals
and the stem o-ring. Regular seal and ring replacement will substantially
extend the life of the valve.
INTERNAL PARTS: Replacement of the spring, seat, ball and stem in addition
to all rings and seals.
NOTE:
When the valve has been properly operating in a partially opened
or closed position or for long periods of use with extremely corrosive
fluids, replacement of all or some internal parts may be necessary. If
internal metal parts show wear, replace them. If not, they may be returned
to the valve. Always replace rings and seals, even if they appear not to
be worn.
Disassembly
For all types of repairs, follow this
step-by-step procedure to insure proper disassembly and reassembly:
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From the box end of the valve,
remove the SNAP RING. Tap out the LOCKING SLEEVE. Loosen, pull (or
tap) to the inside, and remove each of the three pieces of the SPLIT
RETAINING SLEEVE. Tap out the UPPER SEAT using a wooden punch and
being careful not to damage the seat.
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Close the valve with the operating
wrench. It must be in the FULL CLOSED position to remove the
VALVE BALL. Use the wooden punch to knock the ball out the box end of
the body. To remove the OPERATING STEM, fit the operating wrench into
the stem. Knock the stem into the inside of the body by striking the
wrench with a hammer.
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Use the wooden punch to remove the
LOWER SEAT being careful not to damage the seat during removal.
Inspection
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Carefully inspect all metal parts
for wear, nicks, scrapes or deep abrasions and replace if necessary.
Remove ALL o-rings and seals from the seat and stem, and install new
WN-1 replacements,
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Carefully check the stem hole in
the body for damage. Buff out the stem hole to remove any corrosion,
being careful not to remove too much metal. It is important that this
surface is clean and smooth before reassembly. NOTE: If fluid has caused
any washed areas in the stem hole, if any cracks are found in the stem
hole, or if the stem hole has become too oversized, the valve should
not be reassembled. Instead, return the valve body to WNCO Valve for
repair. Often the body can be repaired by machining the stem hole to
oversize specifications and installing an oversize operating stem.
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Clean and inspect the box and pin
connections and the operating stem hole as per standard blacklight, magnetic
particle inspection. Either of the joints may be reworked if there is
enough space left for tong purposes after the joint is remachined. If
the stem hole is found cracked, even if no evidence of pressure
leakage is detected, the valve body must be replaced. A crack in the
stem area can severely weaken the strength of the valve.
Parts Assembly
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Install the wave SPRING and the
LOWER SEAT (with Teflon seal ring facing up). The OPERATING STEM
should be put into place in the CLOSED POSITION. The VALVE BALL will
slide easily into the stem cog. Install the UPPER SEAT (with Teflon
seal facing down).
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Insert the lower 3-jaw puller from
the pin end of the body and grasp the UPPER SEAT with the jaws. Use a
wrench to tighten the nut on the stem of the puller and compress the
internal parts against the spring. Install the three pieces of the
SPLIT RETAINING RING into the body groove and slide the LOCKING SLEEVE
into place inside the split ring. Remove the 3-jaw puller. Install the
snap ring.
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Install a grease zert in the body.
Use a heavy duty water repellent grease and grease the valve
thoroughly. Remove the grease zert and install the plug.
The valve is now ready to be pressure
tested and placed back in service or stored for future use.
Routine Maintenance
Lubrication: All WN-1 kelly
valves are designed with a grease fitting located opposite the stem. At
least three times a week, remove the plug, install the zert and lubricate
with a heavy water repellent grease. Replace plug before resuming
operation.
TIP: Always grease the valve
thoroughly and operate the stem several times after removing the valve
from the drill string, even if only storing the valve for a short period
of time. This will help prevent drilling mud from setting up inside the
valve and freezing the ball and stem.
Operation: Open and close the
valve two or three times a week to help keep the parts free of debris.
NEVER operate the valve in a partially open or closed position; always
open or close the valve fully.
Testing: Check connections
and pressure test regularly just as you would with all BOP equipment.
Pressure test kelly valves according to API Spec. 7.
WN-1 Valves are precision manufactured
to provide maximum life with a minimum of maintenance. Bt following these
routine procedures, longer and more trouble free operation is assured.
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