Richter RSI Series - Manual (Page 6)

Series RSA , Mechanical Seals, external, single or Page 6
double, type Crane 58U – 58U
9485-060-en Revision 11
TM 8046 Edition 10/2010
5.1.3 Assembly bracket chamber
single mechanical seal
Insert mating ring 475/1 in the appropriate bracket
device.
Place intermediate ring 509/1 on the mating ring.
Secure mating ring adapter 487 with the hex.
screws 901/4. Tighten screws in diametrically
opposite sequence..
Tightening torque group 1 = 160 in-lbs (18Nm)
Tightening torque group 2 = 213 in-lbs (24Nm)
Push rotating unit 470/1 onto the protective shaft
sleeve 524 but do not secure yet.
Insert shaft sleeves 523/2 and 523/3 into the
protective shaft sleeve 524.
Push pre-assembled protective shaft sleeve onto
the pump shaft 210. Make sure that the ring carrier
grooves of the protective shaft sleeve 524 engage
exactly into the stud connections 562/1 of the shaft
210.
CAUTION: If assembly is not accurate,
there is a risk of breakage on the
protective shaft sleeve.
Carefully mount pre-assembled bracket unit onto
the appropriate centering of the bearing pedestal
330. Pay attention to the concentric alignment with
the protective shaft sleeve 524.
Tighten hex. screws 901/10 in diametrically
opposite sequence.
Tightening torque group 1 = 398 in-lbs (45Nm)
Tightening torque group 2 = 486 in-lbs (55Nm)
Pre-tension rotating unit according to the
regulations of the mechanical seal manufacturer. A
special clamping device can be used for this
purpose (see Section 10).
Mount mechanical seal guard 685 and secure with
hex. socket screws 914/1 and washers 554/1.
5.2 Double mechanical seal
type Crane 58U – 58U
It is important to replenish in good time any barrier
fluid which has escaped and to monitor the barrier
fluid pressure
The minimum barrier fluid pressure must never be
undershot as long as the pump housing is under
pressure.
Refer also to the description of the pressurisation
system used and Section 4.2.2.
If the sealing liquid pressure is too high, this indicates
a defect in the mechanical seal even though the
mechanical seal on the atmosphere side is completely
tight.
The pump must then be shut down so that no serious
damage occurs.
Substantial damage generally occurs if the aggressive
process medium enters the pressurisation system as
a result of a drop in the barrier fluid pressure to below
the minimum pressure.
If there is a risk that pressure surges occur in the
plant, precautions must be taken to prevent damage.
The barrier fluid pressure can, for example, be
increased to the pressure limit of the mechanical seal
in use.
Dismantling can be checked using the sectional
drawings in Section 7.3 and Section 9 of the
installation and operating manual RSA or RSI as well
as the components available.
5.2.1 Dismantling
Remove the bracket 344 including complete
mechanical seal and protective shaft sleeve 524
from the shaft 210 by raising it.
Deposit bracket 344 with the plastic side facing
downwards on a soft surface.
Remove screw-in pipe connectors 917/1 and 917/2
from the seal housing 483.
Undo hex. screws 901/4 and remove the seal
housing 483 upwards out of the bracket chamber.
CAUTION: Make sure that no
mechanical seal parts fall as they may
be raised automatically (risk of
breakage).
Remove the remaining mechanical seal parts from
the protective shaft sleeve 524 resp. out of the
bracket 344.
When changing the rotating unit 470, observe the
operating manual of the mechanical seal
manufacturer.
5.2.2 Notes on assembly
Only use original spare parts.
Do not use any defective parts.
The recommendations of the mechanical seal
manufacturer are to be observed.
If the rotating units are moved by a key, the two
seal halves are to be pushed from both sides onto
the protective shaft sleeve. Otherwise the
secondary seal would be damaged on the sharp
edges of the key groove.
Mount rotating unit 470/2 with pumping thread on
the impeller side.
The rotating units 470/1 and 470/2 must be flush.