TM 10-4610-243-13
4-31. GATE VALVE ASSEMBLY (4-INCH) REPAIR - cont.
(13)
Remove two screws (13) and separate discs (14 and 15) from disc riser (16).
(14)
Remove disc riser (16) from stem (12).
(15)
Unscrew stem (12) from bottom of bonnet (10).
b.
Cleaning.
(1)
Wash all components with clean water and detergent.
(2)
Rinse components in clean water and dry with wiping rag.
c.
Inspection.
(1)
Inspect bonnet (10) and valve body (17) for cracks, scored mating surfaces, stripped threads and
corrosion.
(2)
Inspect for bent stem (I 2) and galled or stripped threads.
(3)
Inspect sealing surfaces of discs (14 and 15) and valve body (17) for deep scratches and cracks.
(4)
Inspect male coupling (9, figure 4-26) for cracks and corrosion.
(5)
Inspect female coupling (19) and cap (3) for cracks and broken locking arms.
d.
Repair. Replace damaged or defective parts. Replace all sealing components.
e.
Assembly.
Assemble gate value. Refer to figure 4-28.
(1)
Screw stem (12) all the way into bottom of bonnet (10), then back out stem three full turns. Do not allow
stem to move from this position.
(2)
While holding stein (12) in place, screw disc riser (16) onto stem until bottom of riser is flush with end of
stem.
(3)
Position discs (14 and 15) on riser (16) and install two screws (13).
(4)
While preventing stem (12) from turning in bonnet (10), turn discs (14 and 15) and riser (16)
counterclockwise onto stem until top of discs contact bottom of bonnet.
(5)
Position gasket (11) on valve body (17).
(6)
While holding stem (12) in position, lower bonnet (10) and discs (14 and 15) into valve body (17). Do not
rotate discs more than 1/4 turn to aline discs with body.
4-86
