Flowserve Factory Mutual Approved Oil or Gas Safety Shutoff Valve - Manual (Page 5)

WCAIM2054 Factory Mutual Approved Oil or Gas Safety Shutoff Valves 5
b. The stem and body surfaces that the thrust bearing(s)
and stem seal(s) contact must be undamaged, clean, and
free of pit marks and scratches.
C. Reassembly (Refer to exploded views on pages 6 and 7)
1. Reassemble Z|v"–2" 44 and Z|v"–1Z|x" 59 three-piece valves as
follows:
a. Lightly lubricate the ball, seats, body seals, stem seals
and thrust bearings with a lubricant compatible with the
media being handled. White petroleum jelly is a good
general-purpose lubricant.
b. Place new PEEK thrust bearing protector (Tan) and new
thrust bearing (black) on stem and insert assembly
through body cavity. Thrust bearing, stem seals, thrust
bearing and stem seal protectors that are the same size
and color are generally interchangeable.
c. Install new stem seals (black), stem seal protector (tan)
and the old follower. PEEK thrust bearing and stem seal
protectors are placed outside of seals and bearings. The
seals/bearings must contact the body. Install new Belleville
washers (two pairs of washers with outer edges touching).
Install self-locking nut. Holding the stem with a wrench,
tighten nut until Belleville washers are compressed flat (nut
will bottom); then back off nut
Z|c of turn. Do not
overtighten as a reduction in seal life will result.
d. With stem in closed position, replace ball and install new
seats. With valve in open position, carefully insert new
body seals and place center section between pipe ends.
CAUTION: Do not scratch body seals when replacing
valve body.
e. Replace and tighten body bolts and nuts per torque
figures and method found in Section I.A.2.I.
2. Reassemble 2"–4" 59 three-piece valves as follows:
a. Lightly lubricate the ball, seats, body seals, stem seals
and thrust bearing with a lubricant compatible with the
media being handled. White petroleum jelly is a good
general-purpose lubricant.
b. On 3" and 4" valves, reinstall stem centering washer(s)
into the recesses in the body. When only one washer is
used, it goes inside recess at top of the body and under
the stem seals(s).
c. Place new thrust bearing on stem and insert through
body cavity. The thrust bearing can be distinguished from
the stem seals by the darker color of the 25% filled
fluoropolymer used in the thrust bearing. Thrust bearings
and stem seals are the same color and size, and are
interchangeable on 2" size valves only.
d. Install new stem seals over the top of the stem and down
into the recess in the top of the body. The follower is
installed on top of the stem seals. Place spacer onto the
valve stem.
e. Replace retaining nut onto stem. Using wrench to prevent
stem rotation, tighten the retaining nut to fully compress
packing, then back off
Z|n turn. Excessive tightening
causes high torque and shorter seal life.
f. With the stem in the closed position, install ball, new
seats, and seat retainer (if used). Open the valve and
install new body seals.
g. Place center section between pipe ends and replace bolts
or studs and torque to figures in Paragraph I.A.2.I.
After the valve is assembled, it should be cycled a few
times to ensure that the valve operates smoothly with no
chattering of the ball. The normal operation is an initial
high torque to “break” from the closed position to a
smooth running lower torque mid-cycle, to a high torque
at the end of the 90° cycle or open position. The torque is
similar when closing.
3. Reassemble 2" 51/52 flanged valves as follows:
a. Lightly lubricate the ball, seats, body seals, stem seals
and thrust bearings with a lubricant compatible with the
media being handled. White petroleum jelly is a good
general-purpose lubricant.
b. Install new far seat in the body cavity.
c. Place new PEEK thrust bearing protector (tan) and new
thrust bearing (black) on stem and insert assembly
through body cavity. The thrust bearing, stem seals,
thrust bearing and stem seal protectors that are the same
size and color are generally interchangeable.
d. Install new stem seals (black), new stem seal protector
(tan) and the old follower. PEEK thrust bearing and stem
seal protector are placed outside of seals and bearings.
The seals/bearings must contact the body. Install new
Belleville washers (two pairs of washers with outer edges
touching). Install self-locking stem nut. Holding the stem
with a wrench, tighten nut until Belleville washers are
compressed flat (nut will bottom); then back off nut
Z|c of
turn. Do not overtighten as a reduction in seal life will
result.
e. Install ball, new body seal, new second seat and end plug.
When end plug and body are metal-to-metal, end plug
face may project up to .009" beyond surrounding serrated
surface. End plug must be fully tightened against
machined step in body. If in doubt, assemble end plug
without seat and seal, make a witness mark, and
reassemble the full assembly.
4. Reassemble 3"–8" 51/52 flanged and 3"–4" 4 (151) flangeless
valves as follows:
a. To reassemble, stem disassembly procedure should be
followed in reverse order. The thrust bearing can be
distinguished from the stem seals by the darker color of
the 25% filled fluoropolymer, used in the thrust bearing.
Be sure to replace any washers removed from the body.
Flow Control Division
Worcester Controls