IMO-270EN
5
3.2
Assembly
1. Clean all valve components.
2. Inspect all components for damage before reassem-
bling the valve. Look for damage to the sealing areas,
stem, body and body cap, and look for wear in the
bearing areas. Replace any damaged parts.
3. Carefully clean and polish the ball sealing surface. It
should be free of all scratches and grooves.
4. If the ball is slightly damaged, it may be possible to
smooth the sealing surface with crocus cloth or equiv-
alent. If deep scratches are present, replace the ball or
return the valve to the factory for service.
5. Standing the body (1) carefully on end, install one seat
(7).
6. From inside the valve, place a thrust bearing (70), a
secondary stem seal (71), and the second thrust bear-
ing into the stem bore. (See Figure 1 for proper ori-
entation.) Place the spring (36) into the bottom of the
stem.
7. Insert the stem (5) from inside the body through the
bonnet of the valve.
8. Install the packing (69). (If the packing is V-ring type,
be certain that they are installed in the orientation
shown in Figure 1.) If the valve is to be grounded,
remove one middle V-ring and place graphite ground-
ing washer on top of stack. (See Figure 1.)
9. Place compression plate (10) over the stem (5) and
studs (14). Place stop bushings (50) and nuts (18) on
studs (14) and tighten “finger tight,” then tighten an
additional 1/4 turn.
10. Install the ball (3) rotating it onto the stem (5) in the
closed position. Gently rock the ball to make sure the
stem is centered in the ball slot (see Figure 1, stem-to-
ball location).
11. Gently place the body gasket (65) into the machined
recess of the body (1).
12. Place the remaining seat (7) on top of the ball.
13. Place the body cap (2) over body studs (12) being care-
ful to properly orient body cap and body as originally
assembled by matching orientation marks made prior
to disassembly. Take care not to damage body gasket
(65) or seat (7) during this operation.
14. Lubricate the threads and face of nuts (16) with Never-
Seez® or equivalent. Install nuts (16) on body studs (12)
and tighten sequentially as shown in the diagram
(Figure 2), to the recommended torques as shown in
the torque chart (Table 1).
15. Place the indicator stop (32) with “bottom”facing down
over the stem so that the longer part is over the body.
16. Place the spring (33) over the stem (5) with the larger
diameter contacting the indicator stop (32).
17. Compress the spring (33) and hold down by putting
the retaining ring (34) in the groove in the stem (5).
18. If the valve is to be grounded, test as follows:
a. Use an ohmmeter accurate to /-10%.
b. Check continually between top of stem and body
base metal, also check between ball and body base
metal. Precaution should be taken to prevent
scratching the ball O.D.
c. Resistance in either the open, half open or closed
position shall not exceed 10 ohms using a source
not exceeding 12 volts.
Figure 2
1
BOLT TIGHTENING SEQUENCE
1
1
2
4
2
2
3
3
3
8
4
4
5
5
6
6
7
TABLE 1
Recommended Torques – FT•LBS (N•m)
Fastener Material
A193
A193
A193
A193
GR.B7
BR.B8
GR.B7M
GR.B8M
Fastener Ident. Mark
B7
B8
B7M
B8M
1/2” - 13
75 – 85
70 – 85
55 – 65
60 – 75
(102 – 115)
(95 – 115)
(75 – 88)
(81 – 102)
5/8” - 11
160 – 190
155 – 180
125 – 145
135 – 160
(217 – 258)
(210 – 244)
(169 – 197)
(183 – 217)
3/4” - 10
250 – 290
235 – 275
190 – 220
205 – 240
(339 – 393)
(319 – 373)
(258 – 298)
(278 – 325)
Fastener
Size
