Flowserve WK70 Series - Manual (Page 2)

Flow Control Division
Worcester Controls
D. REBUILDING
a WARNING: BALL VALVES CAN TRAP PRESSURIZED FLUIDS
INSIDE THE BALL CAVITY WHEN CLOSED.
If the valve has been subjected to hazardous media, it must be
decontaminated before disassembly. Follow the steps below for safe
removal and disassembly procedure.
• All personnel involved in the removal and disassembly of the valve
should be equipped with proper protective gear such as face shield,
gloves, apron, etc.
• Relieve the line pressure and cycle the valve back and forth a few
times prior to removal.
• Position valve half-open and flush the line to remove any residual
hazardous media.
1. A standard repair kit is available for these valves. Use repair kit
designation WKRK70 for both WK70 and WK74 valves. The kit
consists of seats, body seals, four Belleville washers, stem seals
and thrust bearings. Specify the material of the seats and body
seals, size, Series and R number (revision no.) of valve or for
non-standard valve, the “P”, “T”, “C”, or similar number, as found
on the handle, the valve nameplate or the actuator bracket
nameplate.
To Order: Valve Size/Series/RK 70/Material/Revison Number, or
P,T,C, or similar number
Example: 1" WK RK 70 RT T1510
CAUTION: If the replacement seat and seal material differs
from those being removed, the valve nameplate or stop MUST
be replaced or altered to indicate the new material /new rating
or valve tagged to so indicate.
2. To replace seats and seals:
a. Place valve in open position. Remove three body nuts and
bolts and LOOSEN the fourth, swing out the valve center
section from between the pipe ends.
b. Now, with valve in closed position, remove old seats, body
seals and ball.
c. Remove handle nut, lockwasher, and handle (if manual
valve). This step is not applicable to valves with single self-
locking stem nut.
d. Using handle or a wrench to prevent stem from turning,
remove retaining or self-locking stem nut, Belleville washers,
and follower from the stem. Remove stem through body
cavity.
e. Remove thrust bearings from body or stem, stem seals and
seal protector from the recess in the top of the body.
f. Clean/remove all foreign matter from the sealing surfaces of
the valve and the ball.
NOTE: The ball and the surfaces against which the seats and seals are
installed should be undamaged, clean, and free of pit marks and
scratches. Light marring from the action of the ball against the seats
is normal and will not affect the operation of the valve. Flaws that can
be seen but barely detected with fingertips are acceptable. The stem
and body surfaces that the thrust bearing and stem seals contact
must be undamaged, clean, and free from pit marks and scratches.
g. For stem area rebuilding, refer to exploded view and stem
build illustrations on the next page.
Order of Assembly:
Place new thrust bearings on stem and insert assembly
through body cavity. Place new stem seals, stem seal
protector, and the follower in position. PEEK thrust bearing
and stem seal protectors are placed outside of seals and
bearings. The seals/bearings must contact the body.
Stem seals, stem seal protectors and thrust bearings that are
the same size and color are generally interchangeable.
h. Place two new Belleville washers in position with their larger
diameter faces touching each other.
For those valves with single self-locking stem nut, place four
new Belleville washers in position (two pairs of washers with
larger diameter faces touching).
i. Thread retaining or self-locking stem nut onto stem and using
handle or a wrench to prevent rotation, tighten the nut snugly.
Follow Section C-Maintenance for proper stem adjustment.
j. Replace one-piece handle and stop (if manual valve),
lockwasher and handle nut onto stem. (This step is not
applicable to valves with self-locking stem nut).
k. With valve in closed position (stem flats oriented across the
pipeline) replace ball (see note on page 4) and new seats.
With valve in open position, carefully insert new body seals
and place center section between the pipe ends.
2 Tube Bore Clean Valves: 1 /
2
" – 2" WK70 and 1 /
2
" – 2" WK74 Installation, Operation and Maintenance 12630-B