Richter RG4 stationary, double - Manual (Page 4)

Series SCK Mechanical seal RG-4, stationary, double, liquid sealed Page 4
9220-064-en Revision 10
TM 7827 Edition 03/2010
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 m
3 /h can be determined with the pump
characteristic curve.
2 , 10
) (kg/dm x (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 - quench or sealing medium inlet
SA - quench or sealing medium outlet
See also 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.
5 Maintenance
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 sealing
liquid which has escaped and to monitor the sealing
liquid pressure. The minimum sealing liquid 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
sealing liquid pressure to below the minimum
pressure.
If there is a risk that, for example, pressure surges
occur in the plant, precautions must be taken to
prevent damage. To this end, for example, the sealing
liquid pressure can be increased. However, this is
only possible up to the pressure limit of the
mechanical seal used.
5.1 Dismantling of a mechanical
seal RG-4, liquid sealed
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 RG-4
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.
Move the back plate almost up to the impeller with
light hammer blows.
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 a result.
See Dismantling in Sections 7.7.1 and 7.7.5 in
the installation and operating manual SCK.
Loosen 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.
With some pump the work sequence is to be
repeated once or twice sizes so that the cup
springs 950/1 can be completely relieved.
Then completely remove the impeller 230. Remove
the mating ring 475/1 and the flat gasket 400/1.
Remove back plate (for sequence, see Sections
4.2.1 and 7.7.4 in the installation and operating
manual SCK) with centering ring 511, O-ring
412/3, seal face 472/1 and intermediate ring
509/1.