HP 20598 Operating Instructions And Parts Manual page 6

Operating Instructions and Parts Manual
Self-Priming Engine-Driven
Centrifugal Pumps
Maintenance (continued)
NOTE: To keep shaft from turning, hold
impeller while unthreading impeller
fastener.
3. Pry seal seat from impeller recess
with a screwdriver (See Figure 1).
Figure 1 – Mechanical Seal
Replacement
4. Remove adapter by unthreading
adapter fasteners (Ref. No. 5) and
fastener seals (Ref. No. 4). Press old
seal head and adapter seal (Ref. No.
24) out of adapter by pushing from
engine side.
5. Clean adapter and impeller seal
recesses before installing new
pieces.
6. Carefully wipe polished surface of
new seal seat with a clean cloth.
7. Wet rubber portion of seal seat
with a light coating of soapy water.
8. Press seal seat squarely into recess in
impeller. If seal seat does not press
squarely into recess, it can be
adjusted by pushing on it with a
piece of pipe. Always use a piece of
cardboard between pipe and seal
seat to avoid scratching lapped,
highly polished surface of seal seat
(handle it carefully).
020598 and 020599
9. After seal seat is in place, ensure
that it is clean and has not been
marred.
10. Using a clean cloth, wipe shaft and
make certain that it is completely
clean.
11. Place adapter seal (o-ring) onto seal
head behind flange and press
assembly into adapter as shown in
Figure 2.
head.
Figure 2 – Mechanical Seal
Replacement
12. Secure adapter on engine mounting
face, using fasteners and fastener
seals. Be sure to replace gasket (Ref.
No. 31) between engine and
adapter, if removed during disas-
sembly.
avoid cocking or damaging adapter.
13. Replace impeller and shims, ensur-
ing that key (Ref. No. 8) is in place
and lock impeller to shaft with fas-
tener and impeller seal on fastener.
14. Replace volute seal and volute with
fasteners, ensure that check valve
(Ref. No. 12) is in place then
remount casing seal and pump cas-
ing with fasteners and nuts.
6
Do not touch or wipe
polished face of seal
Tighten adapter fas-
teners evenly to