Hydraulic installation
Hydraulic accessories
24
© Lutz-Jesco GmbH 2014
BA-10103-02-V01
Stepper Motor-driven Diaphragm Dosing Pump
MEMDOS SMART LK
Operating instructions
8.7.2 Contact-type water meter
The contact-type water meter measures the throughfl ow in a pipe and
sends a pulse to the dosing pump, which then starts dosing. This means
that ideal proportional dosing is also possible with large throughfl ow
fl uctuations.
The Contact Water Meter connects to connection socket 2 (see chapter
9.2.2 „Connection socket 2“ on page 31).
You determine the ratio of throughfl ow and executed strokes of the
dosing pump in "Pulse input" mode, (see chapter „Water meter“ on page
43).
Fig. 19: MEMDOS SMART LK installation on contact-type water meter
8.7.3 Pressure-relief valve
Pressure relief valves have an important safety function for protecting the
dosing pump and the associated pipes and fi ttings. The dosing pump can
generate a pressure that is many times the rated one. A blocked pressure
line can lead to dosing medium escaping.
An improperly high pressure can occur if:
the shut-off valves are closed even though the dosing pump is
running,
pipes block.
At an appropriate pressure, a pressure relief valve opens a bypass line
and protects the system in this way from damage caused by over-pres-
sure.
Notes on assembly:
The line for returning dosing medium from the pressure relief valve
must be routed to the dosing tank or to a collecting pan.
The pressure in the dosing tank must not be too high so that it is
possible to accommodate the returned dosing medium.
As an alternative, the system can return dosing medium into the
suction line in front of the dosing pump. In this case, there must not be
a non-return valve or a foot valve in the suction line.
You should install the pressure relief valve as close as possible to the
dosing head.
햲
햳
햷
햶
햸
햺
햵
햴
햹
Fig. 20: Installation with pressure relief valve – returning to the suction line
