Goulds Pumps 3996 - IOM - Manual (Page 23)

AUXILIARY PIPING
Auxiliary piping may be required for seal chamber cover
cooling, mechanical seal flush or other special features
supplied with the pump. Consult pump data sheet for
specific auxiliary piping recommendations.
If seal chamber cover cooling is required, follow guidelines
listed below.
1. Flows of 4 l/min. (1 GPM) will generally satisfy
cooling requirements.
2. Cooling water pressure should not exceed
7.0 kg/cm
2
(100 psig).
FINAL PIPING CHECK
After connecting the piping to pump:
1. Rotate shaft several times by hand to be sure that
there is no binding and all parts are free.
2. Check alignment, per alignment criteria outlined
previously, to determine if pipe strain has affected
alignment. If pipe strain exists, correct piping.
ALIGNMENT
Alignment between pump and motor is built in by use of
machined lock fit between the C-face motor and motor
support. No further alignment is normally required.
There is one exception to this. The Model 3196
horizontal ANSI pump bearing frame can be used in the
Model 3996. This frame may be used in emergencies or
when it is desired to minimize inventory. The Model
3196 frame will not give built-in alignment, and normal
alignment procedures must be performed. The Model
3196 frame can be identified by the foot and cooling
jacket on the side.
SHAFT ALIGNMENT
Many users now require a 0.002" T.I.R. alignment to gain
a greater mean time between failure (MTBF). All 3996’s
that have been shipped after 1/9/90 have been aligned at
the factory to .002" T.I.R.
Assembly procedures have been developed to align the
pump shaft and the driver shaft to .002" T.I.R. Each
pump is assembled using a torque range of +10% of the
recommended torque value of the bolts. If .002" T.I.R.
alignment is required by the customer, a final alignment
must be done in the field.
The following is the procedure that has been developed
for the use in the field and on our assembly floor to obtain
0.002" shaft to shaft alignment.
3996 Shaft Alignment Procedure
1. Inspect all machined fits for signs of contamination
or damage. All fits must be clean. If the pump is
new this step is not necessary.
2. Loosen all motor, motorsupport, and casing bolts, but
do not remove.
NOTE: Make sure jack bolts on the casing are
backed off.
3. Move shaft assembly (shaft, housing, and impeller)
away from casing angle face, by adjusting the
bearing housing. A 1/4 turn of bearing housing jack
bolts is sufficient to ensure the impeller does not ride
on the casing angle face. Proper indication cannot be
done with the impeller touching the angle face.
4. Tighten motor hold down bolts in a criss cross
pattern to the recommended torque.
(Refer to the torque values listed in Table 3.)
5. Tighten the motor support bolts in a criss cross
pattern to 90% of the recommended torque value of
the bolts. For example, if the recommended torque
value for the bolts is 60 ft.-lbs., tighten bolts to 54
ft.-lbs.
6. Tighten casing bolts in a criss cross pattern to 90% of
the recommended torque value.
7. Attach a dial indicator to the driver shaft and mark
the pump shaft so the indicator always contacts the
same location on the pump shaft.
8. Rotate both shafts in the same direction and record
the indicator readings every 90
° degrees (4 places).
9. Incrementally increase the torque value and begin to
tighten the necessary bolts to bring the shafts into
alignment. Do no exceed 110% of the recommended
torque values. After each series of tightening, repeat
Step #5 until the desired alignment is achieved.
NOTE: Indicate off the hub to the motor lock I.D., in
the motor support, when supplying the pump less
motor.
10. Reset the clearance between the impeller and casing
angle face to .008 (.015 if using the high temperature
option). Ensure the bearing housing jack bolts are
secured.
3996 IOM 9/2010
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