Varisco S.p.A.
Z.I. Nord - Terza Strada, 9 - 35129 PADOVA – ITALY
Tel.+39.049.8294111 Email: [email protected]
Fax+39.049.8076762 Web: www.variscospa.com
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Several companies supply products for CIP cleaning. Make sure the products used are compatible
with the material to be pumped.
7.2.2 CIP CYCLE
•
Pre-washing with clean water, to empty the pump
•
Basic washing with caustic soda (1-2% at 60-80°C for 10-20 min.)
•
Intermediate washing with clean water for 5-10 min.
•
Washing with nitric acid (1-1.5%) at 50-70° C for 5-10 min.
•
Final washing with clean water for 5-10 min.
Note: The washing speed of liquid detergents should not exceed 2 m/s at any point.
In this cycle the stator is subject to high chemical and thermal stress. Therefore, in this CIP cycle
the pump shall stop and restart, that is, change the relative position of rotor and stator every 2-3
minutes, turning just a few times to make sure that every part of the stator gets cleaned.
7.3 TEMPORARY REST
After stopping the pump, empty it and possibly wash it if:
•
The fluid may solidify.
•
The mechanical seal may get encrusted.
•
The liquid inside the pump may freeze due to the low ambient temperature.
7.3.1 PROCEDURES
7.3.1.1 STATOR
In case of prolonged stop, the rotor may permanently deform the stator on the contact surfaces
(compression-set). In this case a greater pickup torque is required at restart.
It is therefore better to dismount the stator from the pump, pack it to shelter it from air and light and
store it in a cool, dry place.
7.3.1.2 ROTOR
After the stator has been disassambled, rest the rotor on wooden blocks and cover it to prevent
damage.
Before reassembly, degrease and clean the rotor to prevent conflicts with the stator material or with
the product to be pumped.
8 MAINTENANCE
IMPORTANT: All maintenance and cleaning operations must be performed with the
machine at a standstill and cut out from any energy source.
After a stop and before restarting, the machine must be inspected to determine the cause of the stop
command, and act with appropriate measures in order to prevent that from happening again.
The inherent vibrations of a progressing cavity pump are below 2.5 m/sec², therefore they hardly
cause risk or trigger possible failures.
The vibrations, though, may lead to the loosening of the
screws of the pump. It is therefore essential to regularly check the tightening of them
.
8.1 SUPERFICIAL CLEANING
It is important to schedule regular cleaning operations, depending on the liquid to be pumped. The
pump may be cleaned:
