en – Original instructions
e-IXPSA – Additional Installation, Operation and Maintenance Manual
9
NOTE:
Do not operate with the valves closed at the suction or discharge pipe, or both.
For the minimum flow values, refer to Section 5.3. Longer operating sessions with these flows
and the indicated liquids don’t cause additional increase of the pump surface temperature. The
permitted temperature limits can be exceeded on pumps with mechanical seals, due to dry run.
Dry run can occur in case of:
•
Insufficiently filled seal chamber
•
Excessively high gas fractions in the medium
•
Operation outside the permitted working range.
WARNING: Operating temperatures below the minimum values
Make sure that the unit is classified and identified as explosion-proof in the technical data
sheet or order confirmation before installing it in a potentially explosive atmosphere.
1.4.3
Electric switches and control devices, instrumentation and accessories
Electric switches and control devices, instrumentation and accessories, like for example flush
tanks and so on, must meet with the applicable safety requirements and regulations for
explosion protection.
1.4.4
Intended use
Speed, pressure, temperature
The speed, pressure and temperature of the pump and the shaft sealing should not exceed the
limit values given in the data sheet and/or order confirmation.
As they can occur with too fast shut down, keep them under control for example by installing a
non-return valve on the pressure side, fly wheel or air tanks.
They can cause temperature shock and damage or impair the operation of single components.
Permitted Nozzle loads and Torques
The suction and discharge piping must be designed in such way that as little force as possible
is required for pump operation. If this is not possible, the values shown in Section 4.3.3 must not
be exceeded under any circumstances. This applies both when the pump is in operation and
when idle, and therefore for all the possible pressures and temperatures of the unit.
NPSH
The pumped liquid must have a minimum pressure NPSH at the impeller inlet, to ensure
cavitation free operation and prevent pump break off.
When the NPSH-value of the system (NPSHA) lies above the NPSH-value of the pump (NPSHR)
under all operating conditions, this requirement is fulfilled.
NOTE:
Do not operate with the valves closed at the suction and/or discharge pipe.
The curves of every pump type show the NPSH-value of the pump (NPSHR).
