Flowserve Cryogenic Ball Valves - Manual (Page 4)

4 08164-S
Flow Control Division
Worcester Controls
surfaces that the thrust bearing(s) and stem seal(s) contact
must be undamaged, clean and free from pit marks and
scratches.
10. The stem seal is generally thicker than the thrust bearing. If
they are the same size and color, they are interchangeable.
(IMPORTANT: Lightly lubricate stem seal(s) and thrust
bearing(s) with a PTFE-based lubricant such as Fluorolube S-
30 or equivalent, except for valves with V20 or V33 options,
which are assembled dry.)
Valves Without Extension:
11. a. Place a new Polyfill thrust bearing as a protector (Rev. R7
and later valves) and/or a new Polyfill thrust bearing on
stem shoulder and then insert stem through body cavity.
b. Install new stem seal(s), a new Polyfill stem seal
protector (Rev. R7 and later valves), old follower and two
new Belleville washers with larger diameter sides
touching. For those valves with single self-locking stem
nut, install four new Belleville washers (two pairs of
washers with larger diameter sides touching).
Note: Polyfill thrust bearing and stem seal protectors (if
used) are black in color, interchangeable, and are placed
outside of seals and bearings. The seals are bearings
must contact the body. For valves using two stem seals
(Rev. R7 and later valves), the thicker Polyfill stem seal
goes over the thinner Polyfill stem seal. If PEEK thrust
bearing and stem seal protectors (tan in color) were
removed, they must be replaced with the Polyfill parts
(black in color) included in the repair kit.
c. Add the stem retaining nut or self-locking nut and while
holding the stem with the handle or a wrench, tighten the
nut to make snug and firm. Follow Section III,
Maintenance, for proper stem adjustment. DO NOT
overtighten. Excessive tightening causes higher torque
and shorter stem seal life.
d. Replace stop plate and/or handle (if used), lockwasher
and handle nut. (This step is not applicable to valves with
self-locking stem nut).
Valves with Extended Bonnet:
12. a. To reassemble, insert stem extension into valve body.
Place a new thrust bearing onto the bottom tang and
insert it through the ball cavity into the stem hole recess.
Screw both stem pieces together all the way, then
unscrew to align pin holes. Insert new grooved pin until
flush with stem extension.
b. Install the following over the stem extension: the seal
washer (follower), new stem seal, two followers and two
new Belleville washers, making sure that concave surface
of washers face each other. Reassemble stem seal
retaining nut. Holding the stem with the handle or a
wrench to prevent turning, tighten the stem seal retaining
nut to make the stem snug and firm. Make sure that the
stem is in full upward position so that the thrust bearing
is bearing on the valve body. Note that excessive
tightening of the stem seal will only produce higher
torque and shorter seal life. Tighten nut to fully compress
Belleville washers. DO NOT overtighten. Reassemble stop
plate and handle (if used), lockwasher and handle nut and
tighten firmly.
c. Cryogenic Valves C4, size 1 /
4
" to 2" with extended bonnet
manufactured after the month of May, 1984, are equipped
with a new type of handle and stop assembly.
The handle and stop are pinned by the two “drive-lok”
pins as a unit, increasing the bearing area with the stem.
To eliminate the tolerance between the handle and stem, a
socket head cap screw is used to tighten the handle on
the stem. An additional step should be taken during
assembly:
1. With socket head cap screw loose, slide handle and
stop assembly over the stem, add lockwasher and handle
nut, tighten handle nut firmly and then tighten handle
socket head cap screw on stem tang.
Follow Steps 13 through 17 for Both Extended and Non-Extended
Valves:
13. Place the ball (see note below) in valve. Make sure the relief
hole in ball is on the upstream side of valve when in closed
position, to ensure that cavity relief is upstream. Note arrow
stamped on body, on a metal tag welded to the body, or on
the bonnet plate, indicating flow path.
NOTE: For diverter valves, install ball as follows:
V1 (900 Valves) – With handle and/or stem flats in-line
with body main axis and viewed from bolt head side
(normally upstream), one ball port is to the right, one is
down, and the other is on opposite end of valve.
V2 (1800 Valves) – Using the same convention as V1, one
ball port is down, and the other is on the opposite end of
the valve.
14. Open valve.
15. Install new seats, which have been specially prepared by
Flowserve for cryogenic service.
16. Install new gaskets per section I.
17. Cycle valve several times to ensure even displacement of
cryogenic lubrication on seats.
To Replace Seats and Seals in 3"–6" Cryogenic Valves:
NOTE: If stem seal replacement is not required, omit Steps 5, 6, 7, 10,
11, and 12.
D. 1. Open valve.
2. Remove valve from between flanges.
3. Remove end plug retaining screws. Close the valve. Remove
the end plug by tapping the ball on the other side with nylon
or wooden drift.
4. Remove ball, seats and body seal. Discard seats and body
seal.