Richter SCK Series User manual

INSTALLATION AND OPERATING MANUAL
Translation of the original manual
Keep for future use!
This operating manual must be strictly observed before
transport, installation, operation and maintenance
Subject to change without notice.
Reproduction is generally permitted with indication
of the source.
©Richter Chemie-Technik GmbH
9220-063-en Revision 10 Edition 03/2010
Series SCK
Mechanical Seal
double, to DIN EN 12756

Series SCK,double mechanical seal to DIN EN 12756 Page 2
9220-063-en Revision 10
TM 7827 Edition 03/2010
List of Contents
List of Contents ........................................ 2
Relevant documents................................. 2
1Technical data...................................... 2
2Safety, transport and storage ............. 3
2.1 Intended use................................................ 3
3Product description............................. 3
4Commissioning / Shutdown................ 3
4.1 Initial commissioning ................................... 3
4.2 Mechanical seals......................................... 3
4.2.1 Use in an explosive area .................................3
4.2.2 Double mechanical seal to DIN EN 12756 .....3
4.3 Inadmissible modes of operation and their
consequences (examples) .......................... 4
5Maintenance......................................... 4
5.1 Dismantling of double mechanical seal to
DIN EN 12756. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
5.1.1 Dismantling of back plate, impeller and mating
ring carrier.......................................................4
5.1.2 Dismantling of shaft sleeve..............................5
5.3 Notes on assembly ......................................5
6Faults.................................................... 5
7Sectional drawing................................ 6
7.1 L e g e n d . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
7.2 Double mechanical seal to DIN EN 12756 ..6
Relevant documents
Operating manual SCK long-life grease and oil
bath lubrication 9220-050-en
Operating manual mechanical seal of the
manufacturer
1Technical data
Manufacturer :
Richter Chemie-Technik GmbH
Otto-Schott-Str. 2
D-47906 Kempen
Telephone: [phone]
Fax: [phone]
E-Mail: [e-mail]
Internet: http://www.richter-ct.com
Authorised person acc. to machinery directive
2006/42/EG:Gregor Kleining
Designation :
Series SCK, mechanical seal:
double, to DIN EN 12756
Materials :
Seal housing:Stainless steel
Wetted parts:
Mechanical seal: SSiC, carbon, Al2O3, PTFE, FKM,
FFKM etc., see also data sheet
Temperature range : see installation and
operating manual SCK, Section 1
Temperature classes : see installation and
operating manual SCK, Section 2.6.7.

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TM 7827 Edition 03/2010
2Safety, transport and storage
The relevant sections in the adjacent installation and
operating manuals apply to safety, transport and
storage.
This installation and operating manual is only valid in
conjunction with the installation and operating
manuals of
SCK long-life grease and oil bath lubrication
9220-050-en
2.1 Intendeduse
Double mechanical seals for plastic-lined pumps of
the series SCK are suitable for the use of aggressive,
toxic, pure and inflammable media.
The instructions contained in the operating
manual or contractual documentation are to be
observed, if necessary consult the manufacturer.
All the important features are documented in the data
sheet included in the scope of delivery.
3 Product description
For a product description of the pump, see the
installation and operating manual for the SCK series.
Section 7.2
The sectional drawing shows a double mechanical
seal to DIN EN 12756.
All components which come into contact with the
process medium are either lined with plastic or are
made of other resistant materials, e.g. silicon carbide.
4 Commissioning / Shutdown
4.1 Initialcommissioning
See installation and operating manual for the series
SCK.
4.2 Mechanicalseals
The design and material combination are specified in
the data sheet.
The proper condition of the components and
the protective facilities must be ensured to
prevent any risk from escaping medium.
The regulations and recommendations of
the mechanical seal manufacturer must
always be observed.
4.2.1 Use in an explosive area
Use in an explosive area means that only
mechanical seals may be employed which
permit observation of temperature.
The operating manual of the respective mechanical
seal manufacturer is an integral part of this general
operating manual.
This permits, amongst other things, the calculation of
the expected surface temperature at the mechanical
seal. The suitability for the permissible temperature
class as per ATEX is hereby given.
CAUTION:
The permissible temperature class of the complete
unit (pump, mechanical seal, coupling, motor) is
determined by the lowest temperature class of the
individual components.
Example:Pump T4,mechanical seal T3,
coupling T4,motor T4
In both cases the unit may only be used in
atmospheres which may ignite above the temperature
class T3, i.e. >200 °C (>392°F).
4.2.2 Double mechanical seal to
DIN EN 12756
Apump fitted with a double mechanical seal must
not be filled with a product before the
pressurisation system provided has been started
up.
Otherwise damage could occur, e.g. opening of the
wetted sealing gap, before start-up.
To guarantee safe operation, the pressure of the
barrier fluid must be 1-2 bar above the pressure of the
process medium at the mechanical seal at Q=0 m3/h.
It must be ensured that the sealing pressure does not
exceed the admissible pressure of the mechanical
seal used.
The required sealing pressure can be determined as
follows:
2/3 of the delivery pressure at Q = 0 m3/h
+supply pressure
+1 - 2 bar safety margin

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The supply pressure is measured in bar at the pump
suction nozzle. If no measuring point is available, the
supply pressure can be calculated using the following
formula.
Using the same formula, the delivery pressure at
Q=0 m3/h can be determined with the pump
characteristic curve.
2,10
)(kg/dmx(mFS)H
=(bar)p
3

p = supply pressure or delivery pressure
H = supply height or delivery head

=density
Are the available connections correctly made?
SE - barrier fluid inlet
SA - barrier fluid outlet
See sectional drawing in Section 7.2.
4.3 Improper operation and their
consequences (examples)
Improper operation, even for a short time, can
result in serious damage to the unit.
In connection with explosion protection,
potential sources of ignition (overheating, electrostatic
and induced charges, mechanical and electric sparks)
may result from these inadmissible modes of
operation; their occurrence can only be prevented by
adhering to the intended use.
For examples, see installation and operating manual
SCK, Section 6.6.
5Maintenance
The regulations of the mechanical seal
manufacturer must always be observed.
See also the installation and operating manual
for the SCK series.
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 barrier fluid 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
aresult 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.
To this end, for example, the barrier fluid pressure can
be increased.
5.1 Dismantling of double
mechanical seal to
DIN EN 12756
Dismantling can be checked using the sectional
drawings in Section 7 and Section 9 of the
installation and operating manual SCK as well as the
components available.
5.1.1 Dismantling of back plate, impeller
and mating ring carrier
First of all relieve the mechanical seal by undoing
the attachment screws 901/5.
Undo screws 901/6 and washers 554/6 of the
bearing pedestal / back plate.
Undo back plate (for instructions, see Sections
4.2.1 and 7.7.4 in the installation and operating
manual SCK).
Move the back plate almost up to the impeller with
light hammer blows.
Bearing pedestal group 3:
Labyrinth disc 555 must be secured with
two bolts prior to the dismantling of the
impeller. For this purpose there are 2
bores Ø5mm in the bearing pedestal. The
double mechanical seal is relieved of pressure as
aresult. See dismantling in Sections 7.7.1 and
7.7.5 in the installation and operating manual SCK.

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Undo impeller 230 with a strap wrench or
assembly wrench. Right-hand thread.
For assembly aid for impeller, see Section 10.1 in
the installation and operating manual SCK.
See also installation and operating manual SCK,
Section 7.7.1.
With some pump sizes the work sequence is to be
repeated once or twice so that the cup springs
950/1 can be completely relieved without moving
the shaft sleeve 524 in the rotating units 470 of the
mechanical seal.
Then completely remove the impeller 230.
Undo back plate (for instructions, see Sections
4.2.1 and 7.7.4 in the installation and operating
manual SCK).
It may happen that the mating ring carrier 476 is
removed at the same time as the mating ring
475/1.
If the mating ring 475/1 is replaced, remove the
anti-torsion insert stud 560/3.
5.1.2 Dismantling of shaft sleeve
Pull the shaft sleeve 524 with the rotating units
470/1 and 470/2 which are still installed off the
shaft.
When changing the rotating unit, observe the
operating manual of the mechanical seal
manufacturer.
Remove seal housing 483.
Remove mating ring 475/2.
5.2Notes on assembly
Only use original spare parts.
Do not use any defective parts as otherwise the
next damage is pre-programmed.
The recommendations of the mechanical seal
manufacturer are to be observed.
Bearing pedestal group 3:
Always make sure that when installing the
mechanical seal the labyrinth disc is
secured by 2 bolts.
The bolts must be removed again after
assembly of the impeller.
If the rotating units are moved by a key, the two
seal halves are to be pushed from both sides onto
the shaft sleeve. Otherwise the secondary seal
would be damaged on the sharp edges of the key
groove.
PTFE rings are often easier to install if they have
been previously heated in hot water.
The mating ring carrier 476 is designed with an
anti-torsion insert for the wetted mating ring. It
must be ensured that the mating ring is properly
installed in this device.
With some mechanical seal types the rotating units
can be better pushed over the shaft sleeve when
dismantled.
Mount rotating unit 470/2 with pumping thread on
the impeller side.
The rotating units 470/1 and 470/2 must be flush
with the key 940/2.
When pushing on the mating ring 475/1,make
sure that the position of the flat section matches
that on the shaft.
6Faults
Faults may result from inadmissible modes of
operation. Such inadmissible modes of
operation – even brief ones – may cause
serious damage to the unit.
In connection with explosion protection, potential
sources of ignition (overheating, electrostatic and
induced charges, mechanical and electric sparks) can
result from these inadmissible modes of operation;
their occurrence can only be prevented by adhering to
the intended use.
Should there be any uncertainty about the remedy to
be applied, please inquire at your in-house pump
office or at the pump manufacturer's.
See also Section 8 in the installation and operating
manual of the SCK series.

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TM 7827 Edition 03/2010
7 Sectional drawing
7.1 Legend
161
400/2 flatgasket
412/x O-ring
470/x rotatingunit
475/x matingring
476 mating ring carrier
483 sealhousing
524 shaftsleeve
531/2 spring-typeslottedpin
560/3 stud
901/5 hex.screw
917/x screw-inpipeconnector
932/5 circlip
940/3 key
SE = barrier fluid inlet
SA =barrier fluid outlet / venting
7.2 Double mechanical seal to DIN EN 12756
View displaced by 90°