Caution
Caution
Caution
RPH
15
7.5.2
Reassembly (general)
Reassembly is effected in reverse order to dismantling. Use the
general assembly drawing and the list of components for
orientation.
All screws and bolts must be properly tightened during
assembly. For required torques see 7.5.3.
The following additional points must be observed:
1. Use only the bearing types and sizes specified in section
4.3.4. Heat up angular contact ball bearing 320.02 and the
inner race of cylindrical roller bearing 322.01 in an oil bath
or by means of an induction heater to approx. 80
°
C. Prior
to fitting the inner race of the cylindrical roller bearing, slip
the oil thrower, if any (special pump design), onto the shaft
so that the side with the larger diameter rests against the
shaft shoulder. Fasten with grub screw 904.20. Push the
inner race of the cylindrical roller bearing and the angular
contact ball bearing onto the shaft until they will not go any
further.
Angular contact ball bearings 320.02 must
be installed in ’O’ arrangement.
(See section 9.)
Angular contact ball bearings installed in pairs must always
be from the same manufacturer. Bearing brackets B 03 and
B 05: Make sure that discs 550 are positioned correctly.
After having mounted angular contact ball bearings
320.02, screw on and tighten keywayed nut 920.21 using
a C-wrench and without fitting lockwasher 931.01. Let the
ball bearings cool down to approx. 5
°
C above ambient
temperature. Re-tighten the keywayed nut, then unscrew
it again. Put a few spots of Molykote on the contact faces
of the lockwasher and of the keywayed nut, slip on
lockwasher, tighten keywayed nut and bend over
lockwasher.
2.
Cooled version: Note position of O-rings
412.01/.31.
3. For mounting the mechanical seal, proceed as described
on the supplementary sheet, if necessary. Observe the
instructions in section 7.5.4.
4. Check the sliding fit of the shaft protecting sleeve on the
shaft, if fitted.
5. Carefully insert the impeller joint ring, making sure the ring
and sealing surfaces are clean.
6. Slip throwers 507.01/.02 onto the respective shaft shoulder
in such a way that there is a gap of approx. 2 mm between
the throwers and the bearing covers. Lock with grub screws
904.41/.42.
It is of paramount importance that metal-to-metal
contact is established between the casing cover
and the volute casing, and the bearing bracket and the
casing cover.
7. Disengage the assembling jigs from the groove in the shaft
protecting sleeve, if applicable.
8. After installation in the pump casing, which has remained
in the piping, the coupling alignment must be checked as
described in section 5.3.1.
9. Fill in oil as described in section 6.1.1.
7.5.3
Tightening torques
Impeller nut 922.01 or impeller screw 906 shall
be re-tightened some 20 to 30 minutes after
assembly. Bend over lockwasher 931.06.
The screwed connections (item 902.01/
920.01) between the volute casing and the
casing cover must be tightened using a torque wrench.
The tightening torques given in the table shall apply. These
values are determined on the basis of a friction coefficient
m
= 0.12
1)
.
Max. permissible tightening torques
2)
in Nm for studs to
DIN 938/939 with hex. nuts to ISO 4032.
1) The torques given apply to the initial tightening of brand-new threads.
2) After repeated tightening of the threads and in case of good lubrication
the values shall be reduced by 15 to 20 %.
