Flowserve 94 Series - Manual (Page 4)

4 06957-L
c. Remove the stem from the top of the body. This may
require considerable force. The flats on the stem can be
clamped in a vise or other fixture to aid in removal. Avoid
damaging the stem flats. The packing will be removed
with the stem by the shoulder on the end of the stem.
CAUTION: Use care to avoid scratching the surface of
the stem and packing chamber.
d. Remove the packing from the stem.
TO DISASSEMBLE 3"-6" FLANGED ONE-PIECE VALVES:
10. Place valve in closed position. Remove end plug retaining
screws.
11. Remove end plug. If necessary, drive end plug from valve,
using wooden drift applied to face of ball. Be certain the ball
is fully closed.
12. Remove body seal, ball, seats, and seat back seals (if any).
13. Remove the handle assembly, spacer, and stop (if any), gland
bolts, Belleville washers, gland plate and follower(s) (1 or 2
pieces) from the top of the valve.
14. Push the stem down into the body cavity and remove.
15. Remove the thrust bearing and stem packing from the body.
CAUTION: Use care to avoid scratching the surface of the
stem and packing chamber.
C. VISUAL INSPECTION
1. The ball and 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 that can be seen, but barely detected with
fingertips, are acceptable.
2. The stem and body surfaces that the stem seals and thrust
bearing contact must be undamaged, clean and free of pit
marks and scratches.
D. REASSEMBLY
NOTE: Valves with a pressure relief hole in the ball (V3) must be
assembled with the hole upstream when valve is closed. Any
valve with this V3 option will have an arrow indicating
downstream. This arrow is stamped on the body or on a metal
tag welded to the body.
Clean all sealing surfaces of the valve including the ball.
Lightly lubricate the ball, seats, seat back seals (if used), body
seal(s), split thrust bearing and split ring or one-piece thrust
bearing, and stem seals with a lubricant compatible with the
media being handled (except for valves with V38 option, which
are assembled dry) as the parts are used. 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 eqiuvalent. Filled metal seats will be lubricated at the
factory. If they are not, they should be lubricated as previously
stated. The seat back seals will be preassembled to the seat
backs. Do not operate a newly rebuilt valve with filled metal seats
without lubricant.
If graphite parts are used, they should be handled on the flat
surfaces rather than the O.D. These parts can be damaged by
squeezing the O.D. and will not work if they are cracked or
broken. Light flaking of the material is acceptable.
TO REASSEMBLE 1 /
2
"-2" THREE-PIECE VALVES:
1. Insert the stem down through the bonnet and into the body.
2. Place the split thrust bearing in the recessed diameter above
the stem tang. Place the split ring in the same recessed
diameter, under the split thrust bearing (refer to exploded
view).
3. Pull the stem up so that the split thrust bearing and split ring
are drawn into the stem hole recess in the ball cavity. See
instructions 21 through 26 for stem packing and gland plate
assembly.
4. With the valve in the closed position (stem flats going across
pipeline), replace the ball, seats and seat back seals (with “A”
or “G” seats only). Open the ball and add the body seals. For
“S” gaskets, see cautions I.D.1 - I.D.5. If seat back seals are
used, be certain that they are correctly located on the seat
back face before putting the center section between the pipe
ends. Damage may occur and leaks or high operating torque
may result if the seat back seals are not located correctly.
5. Place the center section between the pipe ends and replace
the four body bolts and nuts. Tighten finger-tight. For FZ94
valves, insert the centering rings (if any) into the pipe ends
before installing the center section of the valve.
TO REASSEMBLE 1 /
2
"-2" FLANGED ONE-PIECE VALVES:
6. On all sizes except the 1 /
2
", place the far seat and seat back
seal (used with “A” or “G” seats only) in the body cavity. If
seat back seals are used, be certain that they are correctly
located on the seat back face before installing the ball and end
plug. Damage may occur and leaks or high operating torque
may result if the seat back seals are not located correctly.
7. Insert the stem down through the bonnet and into the body.
8. Place the split thrust bearing in the recessed diameter above
the stem tang. Place the split ring in the same recessed
diameter, under the split thrust bearing (refer to exploded
view).
9. Pull the stem up so that the split thrust bearing and split ring
are drawn into the stem hole recess in the ball cavity. See
instructions 21 through 26 for stem packing and gland plate
assembly.
10. Install far seat ( 1 /
2
" valves only). With the valve in closed
position (stem flats going across pipeline), insert the ball into
the body so that the stem slot engages the tang on the stem.
Flow Control Division
Worcester Controls