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TM 10-4320-342-24
3-17. BALL VALVE (200/600 GPM PUMP) REPAIR - continued.
(2)
Cleaning and Inspection.
(a)
Inspect threaded parts for damaged and corrosion threads.
(b)
Inspect valve body (8) for cracks, damaged and corroded bearing surfaces.
(c)
Inspect insert for cracks and excessive corrosion.
(d)
Inspect ball and seats for corrosion, scratches, gouges, chips and other surface damage that could result in
leaks.
(3)
Repair.
Replace damaged or defective components and all mandatory replacement parts.
(4)
Assembly. Refer to Figure 3-10.
(a)
Apply a thin coat of lubricant to seats (6 and 11), seals (5, 9 and 10) and ball (7) to aid assembly.
(b)
Position valve body (8) on bench with large opening facing up.
(c)
Install seat (11) in valve body (8) with flat surface of seat facing down.
(d)
Press seal (9) into stem bore in valve body (8).
(e)
Install stem (3) up through stem bore in valve body (8). Position as noted during removal.
CAUTION
To prevent premature failure of ball valve, upper stem seals must be installed
correctly. Bottom seal of the seal set must be installed first with flat surface down.
(f)
While holding stem (3) in place, install upper seal (9) over valve stem and into valve body (3).
(g)
Install compression ring (2) and nut (1) on stem (3) and tighten until seals are fully seated, then tighten an
additional 1/8 to 1/4 turn.
(h)
Align stem (3) as noted during removal.
(i)
Align slot in ball (7) with blade on end of stem (3). Insert ball (7) into valve body (8). If required, turn stem
to align with slot in ball. Make certain that stem blade is in the middle of the ball slot (equal distance from
ends of slot). Reposition ball, if required.
(j)
Gently press seal (5) into groove in valve body (8).
3-29
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