Pulsafeeder Isochem RGT IOM - Manual (Page 27)

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d) Install the Impeller outer retaining ring (item 14) by carefully expanding it over the end
of the drive shaft (item 4) and pushing it into the its groove.
Verify that the Impeller floats freely back and forth between the retaining rings. This
requires that both retaining rings be fully seated in their respective grooves.
17. Install the containment can (item 19) in the casing.
18. Install a new containment can “O”-ring (item 28) on the back of the rear housing (item 1).
Placing the “O”-ring in warm water prior to installation will momentarily soften the material
making installation easier.
T HE MAGNETIC ATTRACTIVE FORCE IS CONSIDERABLE . T AKE CARE NOT TO CHIP THE
MAGNETS AND TO AVOID PINCHING OF FINGERS WHEN THE ASSEMBLY SNAPS TOGETHER .
19. Install the rear housing (item 1) to the casing (item 20).
Magnetic attraction will draw the rear housing and the casing together. The use of four
assembly guide pins screwed into the rear housing is recommended. These pins can be made
from 1/4-28 threaded rod or cut-off bolts.
20. Install the rear housing screws (items 26). Tighten evenly to 72 in. –lb (810 N-cm) in an “X”
pattern in small intervals (do not tighten one side excessively and then tighten the opposite
side, as this will tend to crush the TFE “O”-ring and cause a leak).
21. Omitting the front cover “O”-ring, trial assemble the front cover with no shims (item 3).
e) Install and hand tighten the cover bolts (items 15) evenly.
f) Using feeler gauges, measure and record the gap between the rear housing and the front
cover around the circumference of the pump, between each set of cover bolts.
g) Add the six measurements and divide by six to determine the average clearance between
the two surfaces.
h) Reove the bolts and the front cover. Add shims equal to the measurement obtained in
step “c” above. Red shims are 0.002” thick, and green shims are 0.003” thick. Use no
more shims than necessary, as the pressure capability of the pump is directly related to
the internal clearances between the impeller and the housings.
i) After the shims are in place, install the O-ring (item28) over the inner barrel of the front
cover, seating it fully and smoothly against the shoulder.
j) Install the cover, taking care to avoid damage to the outer bearing (item 9) and ensuring
that the O-ring seats in the rabbet in the rear housing without pinching. Install the cover
bolts (item 15) and tighten to 220 in-lb. (2490 N-cm) using the pattern shown in
Appendix B.