Pag.9 (Funct. and Maint.Manual n.03 – Fourth edition) OMI.EN-PCP001 R01
All pumps may be equipped with accessories to improve their performance and in order to
improve safety of plant.
4.6.1 Dry-run protection
The protection against dry run prevents stator damage whenever the liquid is missing. A
thermal sensor is fitted to the stator, and linked to the electric board. If there is no fluid in
the stator, the stator rubber overheats and the increase in temperature activates the
electric circuit, which stops the motor. This device may be installed subsequently.
4.6.2 Protection against delivery overpressure
The overpressure protection consists of a security valve set to the desired pressure and a
bypass pipe which closes delivery or reduces the flow in case the pump may not be
stopped.
4.6.3 Return valve in delivery
In case it is necessary to convey part of the product back to the tank in order to mix or
make the product more homogeneus, it is possible to fit a valve in the delivery.
4.6.4 Electric board
Upon request, pumps can be controlled by an elecric board, consisting of a main switch, a
pilot light, a liter counter, two-position forward/backward selector and a reset emergency
switch. The boards are also equipped with a safety lock. All boards are supplied in
compliance to the low voltage equipment directive 2006/95/CE.
5 PACKING, TRANSPORT, STORAGE
5.1 Packing and transport
Progressing cavity pumps are shipped in containers (boxes on pallets, cases or cages),
unless the customer requires a different system.
