Flowserve 51 Series Flanged Ball Valves - Manual (Page 3)

Flow Control Division
Worcester Controls
WCAIM2014 Z|x" - 2" 51/52 One-piece, Flanged Ball Valves 3
Removing Stem Assembly
Remove handle nut, lockwasher, also separate handle and stop or
one-piece handle/stop (if manual valve). (This step is not applicable to
valves with self-locking stem nut.)
Remove retaining or self-locking stem nut. Prevent stem from turning
with wrench.
Remove and discard Belleville washers. Push stem into ball cavity and
remove. On the
1 /
2
" size, the far seat must be removed before pushing
stem into cavity.
Remove and discard stem seal(s), stem seal protector (if any), thrust
bearing, and thrust bearing protector (if any), which may be on the
stem or in the body stem cavity. Remove and discard the far seat and
the seat seal (if any). Retain the follower.
Visual Inspection:
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 which
can be seen but barely detected with finger tips are acceptable.
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.
Reassembly
NOTE: Valves with a pressure relief hole in the ball (V3 option and
chlorine valve) must be reassembled and installed with the hole
upstream (end plug side) to ensure that cavity relief is upstream
when valve is closed. Any valve with a relief hole will have an arrow
on the body pointing downstream. This arrow is stamped on the body
or on a metal tag welded to the body.
Lightly lubricate the ball, seats, body seal, stem seal(s), stem seal
protector and seat back seals (if any), thrust bearing, and thrust
bearing protector (if any), 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 valve repair kits with “A” or “G” seats, the filled metal seats will
be lubricated at the factory. If they are not, they should be lubricated
as noted in Paragraph B.5. and also as stated above. DO NOT operate
a newly rebuilt valve using filled metal seats without lubricants. The
seat back seals will be pre-assembled to the seat backs.
For CL51/52, and oxygen prepared (prefix code “X”) valves only, lightly
lubricate the ball, seats/body seals, stem seal and thrust bearing with a
PTFE-based lubricant such as Fluorolube S-30 or equivalent.
On all except the 1 /
2
" size, install the far seat and seat back seal (if any)
in the body cavity.
The seat should appear to sit flat into the back of the cavity indicating
that the seat back seal is properly located on the seat. If the seat back
seal is not correctly positioned it could be damaged or cause the
valve to leak.
For stem area rebuilding, refer to exploded view and also the stem
build illustrations and stem component color chart on the following
pages that pertain to the valve being rebuilt.
Order of Assembly:
Place new thrust bearing(s) on steam and insert assembly through
body cavity. Place new stem seal(s), stem seal protector (if any), 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.
NOTE: For valves having graphite stem seal(s), care must be taken
when installing the graphite parts because they are easily damaged by
squeezing the OD of the seals. Handle gently by holding seal(s) on
flat surfaces rather than on the OD. If resistance is encountered when
installing seal(s) over the stem, use follower to gently push the stem
seal(s) down.
Stem seals, stem seal protectors and thrust bearings that are the
same size and color are interchangeable.
Place two new Belleville washers in position with the larger diameter
sides touching each other.
For those valves with single-locking stem nut, place four new
Belleville washers in position (two pairs of washers with larger
diameter sides touching each other).
Place retaining or self-locking stem nut on stem and using handle or
a wrench to prevent rotation, tighten nut to make snug and firm.
Follow section C, Maintenance, for proper stem adjustment.
Replace separate stop and handle or one-piece handle and stop (if
manual valve), lockwasher and handle nut on stem. (This step is not
applicable to valves with self-locking stem nut.)
Install far seat and seat back seal (if any) ( 1 /
2
" valves only), ball (see
Note below), body seal, second seat and seat back seal (if any) 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.
NOTE: For diverter valves, install ball as follows:
V1 (90° Valves) – With handle and/or stem flats in-line with body main
axis, viewed from end plug side (normally upstream) one ball port is to
the right, one is down, and the other is on opposite end of valve.
V2 (180° Valves) – Using same convention as V1, one ball port is
down and other is on opposite end of valve.
For valves with coated stainless steel “S” gasket, install with the wide
flange facing the ball (see view A-A on page 4). Be sure the body seal
is well lubricated.
CAUTION: If the seats and seals installed differ from those
removed, the valve nameplate or stop must be replaced or
remarked to indicate the altered materials and ratings, or valve
tagged to so indicate.