Hi, Mike Austin, General Service Manager with the Gorman-Rupp Company, here today
to demonstrate setting the face clearance on the T2A3-B self-priming
centrifugal trash pump. Before we get started, let's talk a little bit about safety.
Anytime prior to opening up a pump, you always want to make sure that
it is both hydraulically and mechanically isolated. With that in mind,
we can go ahead and get started, but first let's talk about the tools we'll
need to set face clearance. You could possibly need two pry bars to assist in
loosening the rotating assembly from the volute, a 9/16 socket and ratchet,
a feeler gauge, a small screwdriver to help assist in prying out the shims between
the volute and the rotating assembly, and a lathe dog. Now let's get started.
The first thing that you want to do with your 9/16 socket and ratchet is loosen
the four retaining bolts that secure the rotating assembly inside of the volute casing.
Once we loosen the four bolts securing the rotating assembly inside of
the volute scroll, remove two of the screws and insert them into the jacking
holes in the rotating assembly to assist pulling the rotating assembly
back away from the volute.
Once we insert the jacking bolts into each side of the rotating assembly,
let's begin tightening the jacking bolts to pull the rotating assembly away from the volute.
After tightening the two jacking bolts in the rotating assembly,
pulling the rotating assembly away from the volute, you can then pick up a
screwdriver or like tool to remove the shim sets from behind the two locations
where the jacking screws were removed.
After removing the shims from their mounted position between the rotating
assembly and the volute, retain each set separately,
as these sets are of equal combined thickness.
After removing the shims, remove the jacking bolts from
their current locations, inserting them back into a mounting location in the
rotating assembly diagonal from one another.
The next step is to tighten the mounting bolts on the rotating assembly,
pulling the rotating assembly with the
impeller towards the wear plate, while rotating the shaft with a lathe dog at the same time.
Once we've reached a rubbing and nonlocked condition,
the impeller to wear plate clearance is zero.
To determine the required amount of shims to set the face clearance
between the impeller and the wear plate, measure
the gap between the rotating assembly and the volute with your feeler gauge
and add to that gap the required amount of shims of
ten to twenty thousands per the operator's manual.
Once we've determined the amount of shims required
to set the impeller to wear plate face clearance, we can then remove the
mounting bolts from the rotating assembly and pry the rotating assembly
back away from the volute to give you additional space required to insert each
shim set under each mounting location.
After installing each shim set, rotate the tabbed portion inward as a safety precaution.
At this point, we want to tighten down the rotating assembly
inside of the volute and reinstall the lathe dog on
the shaft to ensure that the impeller does not contact the wear plate.
This concludes our demonstration, setting the face clearance on our
T2A3-B self- priming centrifugal trash pump.
For more information on pump hydraulics, equipment, or application engineering,
watch Gorman-Rupp's YouTube channel and visit us at
GRpumps.com