6 Mounting / Installation
Operating manual mzr-2509 Ex/ mzr-2909 Ex / mzr-4609 Ex / mzr-7209 Ex
Last update: October 2016
Technische Änderungen ohne Vorankündigung vorbehalten.
35
Warning
The pump is equipped with a dynamic seal and a direct drive. Therefore the
pump is not hermetic from a technical point of view. That’s why it is
periodically necessary to check the pump regarding leakage.
Please check that all pipes, fittings and screw fittings are tight.
If there is leakage on the suction side it is possible that air penetrates into the
pump. In this case priming will be difficult. At the discharge side the liquid
comes out of the pump. Dry running causes the pump to heat up.
If the pump will be operated within an explosion proof area a check valve right
must be integrated in the pressure line behind the liquid outlet port of the
pump. The check valve has to prevent that the pump empties during shut-
down time.
Behind the discharge port the discharge pipe should be installed ascending..
In case the pump operates against a closed system a safety valve has to be
installed in the discharge pipe to release pressure. In this case the return flow
pipe must go back to the reservoir and not directly to the suction line.
6.6
Filter selection and use
In majority of cases it is recommended to integrate a filter on the suction side
of the micro annular gear pump to ensure its secure operation. The
recommended filter pores or mesh size should not exceed 10 µm. The
penetration of particles or swarf that could cause a blockage or damage to the
pump can only be avoided by using an adapted filter.
HNP Mikrosysteme offers a choice of standard filters covering a broad spectrum
of applications. You may count on our assistance for the selection of the most
suitable one.
In order to select the best adapted filter, such operating parameters as flow
rate, viscosity and degree of pollution of the liquid will be needed. An increase
in at least one of the mentioned terms will require the use of a bigger filtering
element or the pressurization of the delivered liquid. In case no suitable filter
for high viscosity liquid can be found, it is possible to use a filter with slightly
larger pore size. Prior discussion with HNP Mikrosysteme is here recommended.
A filter with larger pores is still better than no filter at all. Alternatively an
already filtered liquid may be used.
Warning
Because filters have a large internal volume, it is recommended to fill in the
filter and the suction tube with already filtered liquid in order to avoid a longer
dry operation of the pump during the startup.
Warning
Please control regularly the filtering elements for pollution. Cleanse regularly
the filter or replace it with a new one. A polluted filter may considerably
decrease the volumetric efficiency of a pump. Furthermore, because of the
cavitation effects dosage imprecision and even pump damage may occur.
Warning
A too small filter (too little filtering surface) may considerably decrease the
volumetric efficiency of the micro annular gear pump. What is more, because
of the cavitation effects dosage imprecision and even pump damage may
occur.
