Pulsafeeder Isochem GM12 Series, Installation, Operation, & Maintenance Instruction

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11
GMH8 & GMC12/16 SERIES
REFERENCE DRAWINGS: SD-2776, SD-2777,
SD-2781
DISASSEMBLY
1. Close discharge and suction valves.
2.
Disconnect power source to motor.
3. Flush and drain pump then remove pump from
the piping. Do not forget to drain the can area
through the front housing drain plug (Item 62 or
63).
4. Remove the bolts (Item 22) which fasten the
front housing (Item 1) to the adaptor (Item 36).
Then separate the pump from the adaptor by
pulling them apart. This will take physical force
because you are pulling against the magnetic
attraction of the drive to the driven magnet. Do
not pry but pull straight apart. Jack out screw
tapped holes are provided on the front housing
to aid in separating the front housing from the
adaptor.
5. Do not remove the drive magnet assembly
(items 31,32) or the drive magnet holder from
the motor unless it or the motor are to be
replaced. This will make reassembly easier
later. The drive magnet assembly is removed
by removing the holder screws (Item 33) then
carefully pulling the magnet assembly off the
holder. Note: the magnets are very fragile and
can be easily damaged by rough handling. The
drive magnet holder (Item 30) can be removed
by loosening the setscrews (Item 35) and
sliding it off the motor shaft or power-frame as
appropriate. Access to the setscrews for the
GMH8 is provided through the slot in the
adaptor. The setscrews for the GMC12/16 drive
magnet holder can only be accessed by
unbolting the power frame assembly from the
adaptor and pulling it out the back of the
adaptor.
6. The next step is to remove the containment can
ring screws (Item 29) and can ring (Item 28). If
the pump has the double can option remove the
nipples (Item 66) first, then the double can (Item
27). The double can has an integral can ring
welded to it. Now the containment can (Item 26)
can be removed from the pump.
7. The driven magnet assembly (Item 24) can be
removed by carefully prying the retaining ring
(Item 10) from the end of the pump drive shaft
(Item 4). The driven magnet can then be
removed from the shaft along with the coupling
keys (Item 21) and other retaining ring.
8. Remove the housing bolts (Item 18) and the
rear housing (Item 3).
9. Remove the center housing (Item 2). The gears
(Items 6, 7) and wearplates (Item 15) are now
accessible and can readily be removed along
with the drive and idler shafts (Items 4, 5).
10. The gears can be removed from the shafts by
removing one of the retaining rings and sliding
the gear off the shaft.
11. Inspect all parts for signs of wear or damage.
The maximum diametrical clearance (bearing
I.D. - shaft O.D.) that is acceptable is .010
inches (.254 mm). Shafts and bearings that are
scored or worn must be replaced. Gears and
wearplates with excessive wear or scoring
must also be replaced.
12. Clean all parts before reassembly.
GMH8 & GMC12/16 SERIES
REFERENCE DRAWINGS: SD-2776, SD-2777,
SD-2781
REASSEMBLY
1. Install the drive and idler gear (Items 6, 7) onto
their respective shafts (Items 4, 5) using keys
(Item 8, 9) and retaining rings (item 10, 11).
Take care not to scratch the shafts when
installing the rings. Check the ends of the
rings for sharp burrs. If a plastic and metal gear
are being used the plastic gear is always the
idler gear.
2.
With the housing pins (Item 17) in the locator
holes in the front housing (Item 1) and new O-
rings (Item 16) installed in the center housing
(Item 2), assemble on the center housing.
3. Install a pair of wearplates (Item 15) and the
shaft assemblies.