Flowserve TB59 - Manual (Page 2)

2 Tank Bottom Valves: 2"–4" TB59 Installation, Operation and Maintenance 06798-D
D. REBUILDING
a 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 be 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 may be ordered for these valves, consisting
of seats, body seals, Belleville washers, stem seals, thrust
bearing, and stem seal 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 number. The information is found on either the
valve nameplate or on the actuator mounting bracket nameplate.
Repair kit ordering examples: 2" TBRK59 RT R0
3" TBRK59 PT T0244
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. Disassembly of valve:
a. Place valve in open position. Remove all studs and nuts, and lift
out center section from between pipe end and tank bottom
flange.
b. With valve in closed position, remove old seats, seat retainer (if
present), body seals and ball.
c. Remove retaining nut from stem — prevent stem from rotating
by holding inside body. (The ball can be inserted and prevented
from rotating with a non-metallic rod such as a screwdriver
handle). This will hold the stem stationary without damaging
the ball.
d. Push stem into body cavity and remove. Retain follower and
centering washer. There is no centering washer on 2" valves.
e. Remove and discard stem seals, stem seal protector and thrust
bearing, which may be stuck on the stem or in the body cavity.
Remove Belleville washers.
f. Clean all sealing surfaces of valve including ball.
3. Visual Inspection:
a. 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 the operation of the valve.
Visible tracking is normal. Tracking which can be felt is a
potential problem.
b. The stem and body surfaces that the thrust bearing and stem
seals contact must be undamaged, clean, and free of pit marks
and scratches.
4. Reassembly:
a. Lightly lubricate the ball, seats, body seals, stem seals, stem
seal protector and thrust bearing with a lubricant compatible
with the media being handled, except for valves with V20, V33
or V38 options, which are assembled dry. White petroleum jelly
is a good general purpose lubricant. For oxygen prepared valves
(prefix code “X”), use a PTFE-based lubricant such as
Fluorolube S-30 or equivalent.
b. On 3" and 4" valves, reinstall stem-centering washer inside
recess at top of the body.
c. Place new thrust bearing on stem and insert through body
cavity. The Polyfill thrust bearing, stem seals and stem seal
protector are the same material, size, black in color, and they
are interchangeable.
NOTE: Valves that had a tan colored PEEK stem seal protector
removed must now use a Polyfill stem seal protector.
d. Install new stem seals, new stem seal protector over the top of
the stem and down into the recess in the top of the body. The
follower is assembled on top of the stem seal protector. Add
two Belleville washers over the follower, with the larger
diameter sides touching each other.
e. Replace retaining nut onto stem. Using a wrench to prevent
stem from rotating, tighten retaining nut to fully flatten Belleville
washer, then back off
¹ ₆ turn.
CAUTION: Excessive tightening causes higher torque and
shorter stem seal life.
f. With the valve in the closed position (stem flats or stem groove
going across the pipeline), install ball, new seats, and seat
retainer (if used). Open the valve and install new body seals.
Flow Control Division
Worcester Controls