M978 Tanker Maintenance Procedures Instructions (Cont)
Pin and hole in stem are tapered. When driving
out pin, small end should be driven so big end
comes out first, or damage to parts can result.
There are two model of butterfly valve. Model A
can be repaired. Model B cannot be repaired.
Refer to TM 9-2320-279-24P for identification of
valves. Do steps (5) through (10) for Model A.
Go to step (10.1) for Model B.
Remove pin (10) from disk (11) and stem (6).
Remove stem (6) from valve body (12).
Seat and preformed packings may come out
Matchmark and remove seat (13) and
two preformed packings (14) from valve
Mark and remove disk (15) from seat (13).
Remove gasket (16), preformed packing (17),
and plug (18).
Remove pin (19) from collar (20) and
remove collar from shaft (21).
(10.1) Remove pin (19) from collar (20).