TM 10-4320-317-13
5-6. MAINTENANCE OF MAIN VALVE ASSEMBLY - (Cont)
NOTE
If new disc is unavailable, turn old disc over.
(4)
Inspect diaphragm (12), disc (14), and spacers (15) for signs of wear, corrosion, and damage. Replace
worn or damaged parts.
(5)
Inspect seat (16) and disc guide (17) for signs of wear, corrosion, and damage. Replace worn or
damaged parts.
d.
REPAIR.
Repair is accomplished by replacement of parts.
e.
ASSEMBLE (Figure 5-3).
(1) Install disc (14) into disc retainer (13).
(2) Install disc (14), disc retainer (13), diaphragm (12), and diaphragm washer (11) onto valve stem (9).
NOTE
If new disc is installed, a different number of spacers may be required to obtain right amount of grip on disc.
(3) Install spacers (15) onto valve stem (9).
(4) Carefully lower stem (9) (on diaphragm and disc assembly) through valve body (4).
CAUTION
When installing stem nut, tighten nut until diaphragm cannot be twisted.
If nut is loose,
diaphragm could pull loose and tear under pressure.
When tightened, make sure disc is not compressed too much. Disc should be compressed only
very slightly by disc guide. If needed, remove enough spacers to obtain proper disc compression.
(5) Install stem nut (10).
(6) Align holes in diaphragm (12) with studs in valve body (4). Stretch diaphragm over studs.
(7) Install spacer (8), spring (7), and spring guide (6) over valve stem (9).
(8) Install stud spacers (5) over studs on valve body (4).
5-9
