Flowserve TB59 - Manual (Page 2)

2 06784-E
Flow Control Division
Worcester Control Valves
C. Maintenance
Tighten retaining nut if seepage is noted at stem.
Cautions: For maximum stem seal life, proper stem, adjustment
procedure must be followed. Excessive tightening causes higher
torque and shorter stem seal life.
1. Tighten self-locking stem nut until Belleville washers are flat, the
nut will “bottom”.
2. Back off nut 1/3 turn.
CAUTION: The self-locking stem nut is difficult to tighten, and
must fully flatten Belleville washers before backing off.
D. Rebuilding
WARNING: Ball valves can trap pressurized fluids in ball cavity
when closed.
Special handling and cleaning procedures are necessary for oxygen
and vacuum service valves. Refer to industry practices when
overhauling these units.
If the valve has been used to control hazardous media, it must be
decontaminated before disassembly. It is recommended that the
following steps are taken for safe removal and disassembly:
- Relieve the line pressure. Operate the valve prior to attempting
removal from line.
- Place valve in half-open position and flush the line to remove any
hazardous material from valve.
- All persons involved in the removal and disassembly of the valve
should wear the proper protective clothing such as face shield,
gloves, apron, etc.
1. A standard repair kit (Worcester’s recommended spares) may be
ordered for these valves, consisting of seats, body seals, Belleville
washers, stem seals, thrust bearing, stem seal protector and
thrust bearing protector. Specify the material of seats and body
seals, size, series and R number (revision number) of valve or for
non-standard valve, the “P” number, “T” number, “C” number, or
similar, as found on the valve nameplate or on the actuator
mounting bracket nameplate.
Ordering Examples:
1" TBRK59 T RO
1 1/2" TBRK59 T TO244
CAUTION: If the seats and seals installed differ from those
removed, the valve nameplate must be replaced or remarked to
indicate the altered materials and ratings, or valve tagged to so
indicate.
2. To replace seats and seals:
a. Place valve in open position. Remove four body bolts and
remove center section from between pipe end and tank
bottom flange.
b. With valve in closed position, remove old body seals, seats or
one—piece seats/body seals and ball.
c. Using a wrench to prevent stem from turning, remove self-
locking stem nut, (4) Belleville washers and follower from
stem. Remove stem through body cavity.
d. Remove thrust bearing, thrust bearing protector from body or
stem, stem seals and stem protector from recess in top of
body.
e. Clean all sealing surfaces of valve including the ball.
Note: The ball and the surfaces against which the seats 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 he operation of the valve. Flaws which can be seen
but barely detected with fingertips are acceptable. The stem surfaces
that the thrust bearings and stem seals contact must be undamaged,
clean and free from pit marks and scratches.
f. Lightly lubricate the ball, seats, body seals, stem seals, stem
seal protector, thrust bearing, and thrust bearing protector
with a lubricant compatible with the media being handled,
except for valves, with V20, V33 or V38 option, which are
assembled dry. White petroleum jelly is good general purpose
lubricant. For oxygen prepared valves (prefix code “X”), use a
PTFE-based (Teflon, Fluon) lubricant such as Fluorlube S-30
or equivalent.
g. Place a new PEEK thrust bearing protector and the Polyfill
thrust bearing on the stem and insert assembly through body
cavity. Place a new thin Polyfill stem seal, a new thick Polyfill
stem seal (black), and new PEEK stem seal protector, and the
follower in position. The thin stem seal and the thrust bearing
are the same size, black in color, and interchangeable. The
PEEK thrust bearing protector and stem seal protector are the
same size, tan in color, and interchangeable.
NOTE: If valve has been cleaned for and is used in oxygen service
(identified by “X” prefix, or V20 or V33 suffix in valve code), Polyfill
thrust bearing and stem seal protectors must be used. They are
included in the repair kit and are the same size, black in color, and
interchangeable with the thrust bearing and thin stem seal.
h. Place four new belleville washers in position (two pairs of
washers with larger diameter sides touching each other).
i. Place the self-locking stem nut on stem andusing a wrench to
prevent stem from turning, tighten selflocking stem nut until
Belleville washers are flat. Follow Section C, Maintenance for
proper stem adjustment.
j. With valve in closed position (stem flats going across
pipeline), replace ball and seats. Valves with Teflon seats have
a one-piece seat/body seal and it is inserted with valve in