Pulsafeeder Isochem RGT IOM - Manual (Page 19)

14
6.4.2 Wear Plate Inspection
Inspect the two wear plates (items 11) for damage or wear.
The carbon wear plates are identical and are recessed in the front cover and rear housing.
They should protrude slightly above the surfaces in which they are mounted (Verify this by
dragging your fingernail across the mounting surface. Your fingernail should catch slightly
as it passes over the wear plate.) If the wear plate does not protrude above the housing,
replace it. Over time friction will cause a deterioration of the wear plates and a resultant
reduction in pressure capability, which is cause for replacement of the wear plate in the
absence of another known cause of pressure reduction.
Use of wearplates that do not meet original specifications may result in contact between the
impeller and housings, causing damage to both components.
6.4.3 Shaft Bearing Inspection
Inspect the Cover bearing (item 9) and the Housing bearing (item 9) for damage or wear. The
maximum diametrical clearance (bearing ID minus shaft OD) is 0.006 inches (0.15mm)
6.4.4 Choke Point Inspection
The “Choke Point” is the area between the two ports, and is the only place where the impeller
and housing run closely together. A near-contact clearance is required in this area to
maintain maximum pressure capability.
Perform an internal inspection as follows:
a) Inspect the outer diameter of the impeller (item 6).
b) Inspect inner surface of the cover (item 2) at the choke point, paying special attention to
the area between the inlet and the outlet ports.
c) Inspect inner surface of the rear housing (item 1) at the choke point, paying special
attention to the area between the inlet and the outlet ports.
Examine this area for evidence of scoring, corrosion, and any other physical damage or wear.