5
Functional description
The metering pump is an oscillating diaphragm pump, the stroke length of
which can be adjusted. An electric motor drives the pump.
The hydraulic end has a fixed safety relief valve (5). The safety relief valve
provides protection for the pump power end and the diaphragm if the liquid
feed pressure becomes too high. If the discharge side of the liquid end is
blocked, the safety relief valve (5) opens at a real opening pressure and
allows the hydraulic oil to flow into the power end housing. The real
opening pressure lies above the nominal pressure (the pressure stage) –
see chap. “Technical Data”.
This does not guarantee protection of the system against overpressure!
Pump
Hydraulic end
Functional description
19