OMI.EN-PCP001 R01 (Funct. and Maint.Manual n.03 – Fourth edition) Pag.16
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:
•
Through the cleaning windows if present on the pump body.
•
Manually, disassembling the pump
•
Automatically (CIP) for pumps with suitable connectors.
8.2 Stators and sealing systems
8.2.1 Stators
Approx. every 900 hours of operation, it is necessary to check the wear, especially for the
stator and the sealing system (packing or mechanical seal).
The frequency of control operations will be determined according to the wear of both of
them, not exceeding anyway 1500 working hours.
8.2.2 Seals
8.2.2.1 Packing seal
Packing seals limit the leakage of product, but do not prevent it entirely. A small leakage is
necessary to prevent excessive friction and subsequent possible overheating.
At startup, after replacement, tighten the gland bush lightly until it is set and in ideal
working conditions (for 10-15 min.), then tighten it more strongly to obtain the smallest
possible leakage.
In case the pack were excessively compressed, the following damages may arise:
•
Dry working
•
Burnt pack
•
Scored shaft (with subsequent leakage of fluid).
