Parr Instrument A3040HC3 - Manual (Page 2)

A3040HC3 Compact Magnetic Drive
P a r r I n s t r u m e n t C o m p a n y 2
Bushing Removal
Remove the A3035HC inner rotor assembly from
the 2721HC3 housing, the upper thrust washer
1132HC sits on top of the inner rotor. The lower
thrust washer will be loose and also easily removed.
Two 1133HC bushings are located in the 2721HC3
housing. The third 1133HC bushing is located in the
end cap. A 1948HC bushing removal tool is recom-
mended to remove these bushings.
Once the inner rotor, thrust washers and bushings
are removed, inspect the housing for any material
deposits that may have collected during operation.
When this unit is completely assembled, there is
about 5 ml of gas space surrounding the inner rotor
assembly. With some applications material may
condense in this area which would necessitate peri-
odic cleaning to remove any build up of debris.
The inner rotor is a welded, sealed unit which will
not require any maintenance. The magnets in this
assembly can be damaged if overheating occurs. It
would then be necessary to replace the complete
A3035HC inner rotor assembly.
Bushing Installation
There are two 1133HC bushings required in the
lower portion of the 2721HC3 housing. A 1947HC2
bushing installation tool is recommended to install
these bushings. Install one bushing into the hous-
ing until it stops against the lower shoulder of the
housing. The second bushing should be installed so
that the top of the bushing is .020” below the larger
diameter area of the housing. The 1947HC2 instal-
lation tool will accomplish this. This leaves a small
internal space between the two bushings in the
housing. Install the third 1133HC bushing in the end
cap.
Thread Lubricant
This drive has been assembled with a small amount
of anti-seize compound (424HC2) on the threads
of the A3076HC end cap where it attaches to the
2721HC3 housing body. When servicing the thrust
washers and bushings, inspect these threads for
lubrication. Add a small amount of anti-seize com-
pound as necessary before reassembly.
O-ring Seal
The standard seal is a 1137HCHA PTFE O-ring seal
mounted at the bottom of the A3076HC end cap as-
sembly. O-rings of alternate materials are available
to meet specifi c research applications if required.
PTFE O-rings should be replaced each time the drive
is re-assembled.
Removing & Installing a Complete Magnetic
Drive Assembly
The A3040HC3 compact magnetic drive assembly
may be removed from the vessel head using the
264AC4 pin spanner wrench furnished with the ap-
paratus. The internal stirrer shaft will need to be re-
moved. Push up on the stirrer shaft, hold the outer
housing and unscrew the stirrer shaft. Insert the pin
spanner wrench into one of the blind openings on
the side of the 2721HC3 housing (located just above
the cooling sleeve), and rotate counter-clockwise.
Cooling Sleeve
The A2685HC cooling sleeve mounted on the
2721HC3 magnetic drive body includes two 827HC
O-rings which seal against the body. After extended
operation these O-rings will require replacement.
To replace the O-rings, remove the magnetic stir-
rer from the vessel head as described previously.
Remove the 825HC retaining ring from the 2721HC3
body and slide the cooling sleeve off. Remove the
O-rings from the inside of the cooling sleeve. Care
must be taken not to scratch the O-ring grooves.
Clean any accumulated lime deposits from the
inside of the sleeve. To reinstall the cooling sleeve,
insert new O-rings into the grooves, moisten the
O-rings with water, slide the sleeve back onto the
housing, and reinstall the 825HC retaining ring.