Hydraulic installations
Hydraulic accessories
26
Stepper Motor-driven Diaphragm Dosing Pump
MEMDOS SMART LB
© Lutz-Jesco GmbH 2014
Operating Instructions
BA-10100-02-V02
8.7.8 Suction pressure regulator
A suction pressure regulator may be necessary if the suction-side
installation of the system demonstrates a varying suction pressure or
supply pressure:
Dosing pumps that are installed above dosing tanks deliver less as
the tank empties, since the suction head increases.
Dosing pumps that are installed below dosing tanks deliver less as
the tank empties, since the positive delivery pressure reduces.
Further problems that can occur:
Greater wear on the dosing pump, e.g. diaphragm rupture due to the
effects of heavy forces with particularly high tanks and high-density
dosing media.
Idling of the dosing tank in the case of a diaphragm rupture or pipe
breakage.
Impermissibly high forces in the pump transmission that occur when
dosing pumps receive the dosing medium directly from the pressure
line.
Reduced performance or destruction of fittings due to cavitation with
long suction lines.
Installing a suction pressure regulator is a remedy for the problems
above. The suction pressure regulator is opened by the dosing pump's
suction pressure. This ensures that no dosing medium can flow if the
dosing pump is not running or no vacuum can be generated following a
pipe fracture.
Notes on assembly:
When using a large suction pressure regulator, you should provide a
pulsation dampener on the suction side.
Fig. 8-16: Installation with a suction pressure regulator
No.
Description
Main line
Injection nozzle with shut-off valve
Pressure line
Dosing tank
MEMDOS SMART LB dosing pump
Wall bracket
Suction line
Suction pressure regulator
Shutoff valve
Table 8-8:
Designation of components
