Table of Contents
Advertisement
Diaphragm Dosing Pump Encore
MB/ME
®
Operating Instructions
7.6 Level control
If a level control is connected, the jack plug has to be covered by a plastic sleeve in order to maintain the protection class. The required sleeve is part of the level
control (also in combination with a suction line).
With the level control connected, the dosing pump stops if the chemical level in the supply tank is low, in order to prevent air bubbles from entering the suction
line and the dosing head. The red LED is lit. As soon as the level contact closes again, the dosing pump restarts.
The level sensor must be designed as a max. N.O. contact.
®
Encore
is equipped with a 2-stage level control. When the first contact breaks (pre-alarm), the red LED begins to flash. The dosing pump continues to operate.
The warning alarm relay is actuated. The dosing pump only stops when the second contact breaks (main alarm). The red LED is lit continuously.
The "level pre-alarm" function is not available if a 2-pin connector and one level switch are used.
NOTICE!
A dummy plug (part no. 29115) must be attached if a level switch is not connected. The dosing pump is delivered with a dummy plug already attached. If a level
switch is to be connected, the dummy plug has to be removed before inserting the jack plug.
7.7 Back-pressure and safety valves
Back-pressure valves are used to optimise the dosing process. They are used:
• to increase the dosing accuracy in the presence of fluctuating back pressures.
• when the dosing lines are long, in order to prevent excess delivery, since the accelerated medium continues moving due to its own inertia even after the
delivery stroke has ended.
• to prevent siphoning, if the supply pressure is higher than system pressure.
Pressure-relief and safety valves are used for overload protection of the dosing pump and the associated valves and lines. They prevent inadmissible pressure
rises in the delivery side system of the dosing pump; for example, if shutoff valves close while the pump is running, or if the injection nozzle is clogged.
The PENTABLOC is a combination valve and performs the functions of a back-pressure valve and a safety valve, among others. It also integrates functions such
as anti-siphoning, pressure relief and dosing control.
7.8 Injection nozzle installation
Injection nozzles are used to inject the metered medium into the main flow, while at the same time acting as non-return valve. The injection nozzle is usually
mounted from the top into the main line. Mounting from below is recommended only for media that have a tendency to crystallize, in order to prevent air bubbles
from being trapped in.
For media that tend to contaminate the injection nozzle, we recommend installing an injection nozzle that can be shut off and removed for maintenance purposes.
a
b
a Injection nozzle mounted from above, b Injection nozzle mounted from below (for media that tend to crystallize)
CF.450.410.001.IM.1114
24
Advertisement
Table of Contents
