15
Operation and Maintenance Manual
QC Series Centrifugal Pump
QC-M02
The following instructions assume that the adapter is assembled and that the spacing
between the impeller and backplate has been set. If not, we recommend you refer to that section
of the assembly directions.
Place the o-ring (
17B
) in the groove of the follower (
17
). Attach the backplate pins (
11F
) to the
backplate (
11B
), take the o-ring (
83E
) and place it in the slot of the stuffing box (
83C
) and place
both parts against the backplate. Screw on the stuffing box (o-ring in place) to the backplate
with the machine screw (
83D
). Be sure to protect the faces of the backplate during assembly.
Pre-assemble the set screws (
80M
) onto the “E” drive collar (
80J
) without penetrating the inner
diameter.
Slide the “E” drive collar, along with the o-ring, onto the stub shaft (
6E
), with the o-ring
pointing towards the tip of the stub shaft. Pre-assemble the o-rings (
80B
) in the carbon seals
(
80
), pushing them to the back of the seat. Place each carbon seal onto a cup (
80G
). These are
the two rotating components that will be balanced on the spring (
80H
) inside the stuffing box
(
83C
).
Be very careful when handling the carbon seals, especially when handling the seal seat, because that
face in particular is crucial in maintaining contact between the stuffing box and backplate.
Carefully slide the carbon seal, o-ring and cup, onto the stub shaft, using the “E” drive collar
(
80J
) as a support for the o-ring. The seal seat of the carbon should be able to touch the follower
(
17
). Slide the drive collar onto the stub shaft. Next, we have to secure the drive collar to the stub
shaft at the proper distance (Regardless of stub shaft model). For help, refer to
Chart 3
which
indicated the spacing values, then take the Vernier caliper and use it to measure that distance
as shown in
Figure G.
Locate the drive collar “E” (
80J
) and secure it with the set screws (
80M
). Place the spring (
80H
) onto
the cup (
80G
). The drive collar has two pins, which drag both cups along the rotations of the stub shaft.
Each cup has a folded leg that initiates traction with the drive collar. Try to place the pins before the legs
of the cups, facing in a counter-clockwise direction.
Figure H.
Now, install the second set of the cup, o-ring and carbon (in that order) onto the stub shaft.
Put the end of the spring into the second cup, just as you did with the first. The seal seat of the second
carbon seal should point towards the backplate (
11B
). Take the sub-assembly of the backplate (
11B
)
with the stuffing box (
83C
) and place it onto the adapter (
71
), making sure that the stuffing box does
not hit the components mounted on the stub shaft. Push in and rotate the backplate until the pins are
locked. If this model does not have backplate pins, place the casing gasket (
90
) into the slot on the
backplate, put on the casing (
1
) and tighten using the clamp assembly (
75
) to secure the backplate.
ASSEMBL
Y
