Bell & Gossett P81875G Series HSC-S Centrifugal Pump - Manual (Page 20)

20
ASSEMBLY
All bearings, “O” rings, seals and gaskets should be replaced
with new parts during assembly. All reusable parts should be
cleaned of all foreign matter before reassembling. The main
casing joint gasket should be made using the upper half as a
template. Lay the gasket material on the casing joint and mark
it by pressing it against the edges of the casing. Trim the gas-
ket so that it is flush with the inside edges of the casing.
1. Assemble Impeller Key (3-911-1) in the shaft key slot.
2. Check the impeller (4-002-0) and casing to determine the
correct relationship (See Figure 33). Heat the impeller
evenly to 300°F maximum to expand the bore.
NOTE: For impellers with replaceable rings, heat each
new ring (4-004-9) and slide it onto the impeller. Hold
rings against the impeller shoulder until they cool.
3. Push the heated impeller on the shaft (3-007-0) against
the shaft shoulder, (impeller may be pressed onto the
shaft if a suitable press is available) (See Figure 12), and
install retaining ring (3-915-1).
4. Lubricate and roll an “O” ring (3-914-2) on each casing
ring (3-003-9) and slide the casing rings onto the impeller.
5. Thoroughly clean the stuffing boxes (3-073-9) to prevent
dirt from entering the seal during startup.
6. Press the stationary seats (3-401-0) of the mechanical
seals into both stuffing boxes. Lightly lubricate the stuff-
ing box bore to ease assembly (See Figure 13).
7. Press a new oil seal (3-177-9) into each stuffing box.
NOTE: Seal lip must point away from the bearing
(3-026-4).
8. Lubricate and roll “O” ring (3-914-1) into the groove in
each stuffing box.
IMPORTANT: Steps 9 through 14 must be completed
with 10 to 12 minutes to assure proper placement of
mechanical seal.
9. Lightly coat the outboard end of the shaft with soapy
water or vegetable oil and slide the mechanical seal head
(3-402-0) onto the shaft (See Photo 7).
10. Slide each stuffing box onto the shaft so that the shaft
end extends through the mechanical seal area, but
does not enter the oil seal. This will permit installation of
deflector (3-136-9).
CAUTION: Extreme Temperature and/or
Flying Debris Hazard
Eye protection and gloves required. Failure to follow these
instructions could result in property damage and/or moder-
ate personal injury.
CAUTION: Extreme Temperature and/or
Flying Debris Hazard
Eye protection and gloves required. Failure to follow these
instructions could result in property damage and/or moder-
ate personal injury.
Photo 8 – Seal Head Installation
Photo 7 – Installing Stationary Seat
Photo 6 – Pressing Impeller on Shaft