Xylem MPAI - Manual (Page 77)

Installation, Operating and Maintenance Instruction
Model MP, MPA, MPAI
MP 100-english page 73 Revision 04
Article No 771074011 Issue 11/2011
Equally all seal casings, auxiliary systems of the
shaft sealing, as well as heating and cooling
systems must be filled carefully.
2.7.2 Marking
The marking of the pump refers to the pump
itself. For coupling and motor resp. further
additions a separate Declaration of Conformity,
as well as a corresponding marking must be
available.
Example of of marking at pump:
CE Ex II 2 G c T... .
The marking shows the theoretically applicable range
of temperature classes. The different temperatures,
permitted acc. to pump design, result as shown in
chapter 2.7.5. The same is valid for the drive.
For a whole unit (pump, coupling, motor) with different
temperature classes the lowest is valid.
2.7.3 Rotation Control
Carry out rotation control with separated
coupling halves only! Refer to chapter 5.5 and
6.1 as well.
If danger of explosion is also existing during
installation, the rotation control must not be
carried out by short start-up of the empty pump,
to avoid undue temperature increase in case of
contact of rotating and stationary parts.
2.7.4 Operation of pump
The pump must only be started up with fully opened
suction side and slightly opened pressure side valve.
The start-up against closed non-return valve, however,
is possible. Immediately after the start-up the
discharge side valve must be adjusted to the operating
point.
Refer to chapter 6.2, as well.
Operation with closed valve in suction and / or
discharge pipe is not permitted!
There´s a danger, that high surface
temperatures are developing at the pump
casing after relatively short time, through fast
heating of the liquid inside the pump.
Fast pressure increase inside the pump can
lead to overload and, thus, the pump can burst.
In chapter 6.4.1 the minimum flow is stated. Longer
operating phases with these flows and the named
liquids don´t cause additional increase of surface
temperature at the pump.
Furthermore the references in chapter 6 of these
operating
Instructions must be taken into
consideration.
On pumps with mech. seals the permitted
temperature limits can be exceeded due to dry-
run. Dry run not only can occur on insufficiently
filled seal casing, but also because of too much
gas in the medium.
Operation of the pump out of the permitted
operating range can lead to dry-run, as well.
2.7.5 Temperature Limits
Under normal operating conditions the highest
temperatures must be expected at the surface
of the pump casing and in the area of the
bearings.
The surface temperature occurring at pump casing
corresponds with the temperature of the pumped
liquid.
If the pump is heated (e. g. heating jacket), care
must be taken, that the temperature classes,
prescribed for the plant are observed.
In the area of the bearing bracket free contact from
surface to surrounding must be given.
During operation of the pump it must be
secured that an overabundant sedimentation of
dust is avoided (regular cleaning), to prevent
heating of pump surface over the permitted
temperature.
The operator of the plant must secure that the
defined operating temperature is observed. The
max. allowed temperature of the pumped liquid at
suction depends on the particular temperature
class.
The following table shows the theoretical temperature
limits of the pumped liquid in consideration of the
temperature classes acc. to EN 13463-1.
Temperature class acc.
EN 13463-1
Temperature limit of
pumped liquid
T4 (135°C) 135°C
T3 (200°C) 140°C
T2 (300°C) 140°C
T1 (450°C) 140°C
The particular allowed operating temperature of
the pump is shown in the data sheet and / or the
order confirmation resp. the type plate at the
pump.
In the area of the bearings the temperature class T4 is
guaranteed, provided that the ambient temperature is
40°C and the appliance is duly operated and
maintained.
2.7.6 Maintenance
For a secure and reliable operation it must be
secured by regular inspections, that the unit is
maintained competently and is kept in good
technical condition.