14 | Operation Manual MIDIDOS E | Installation
The dosing pump is to be erected with the suction and pressure valves in an upright positi-
on. To guarantee its stability, the pump must be screwed appropriately into the ground.
The system’s piping must not put any force on the dosing pump’s connections or valves.
To avoid backfiring dosing after the process end, an electrical and hydraulically locking
device is provided on the dosing pump.
7.3 Drainage discharge
NOTICE!
Released gases can destroy the dosing pump’s transmission!
The drainage as well as the leakages from the separate chamber must slope downwards,
i.e. to go in a descent to the collection tank. Under no circumstances is the drainage pipe
to go direct through the lidded receptacle back to the medium; otherwise the released
gases can infiltrate the dosing pump’s transmission. The drainage pipe must be directed
only to a gas free collection tank (in a decline) or it has to be lead on a decline to a collec-
tion funnel over which it then has to end with enough distance in between. The leakages
can then be directed back via the funnel through the tank cover. Moreover possible
leakages are detected with greater ease from the gap to the collection funnel.
7.4 Pressure sustaining and safety valves
Pressure sustaining valves are accessories for optimizing the dosing process. They are
used:
• to increase the dosing accuracy in the presence of fluctuating back pressure
• with long dosing lines in order to prevent excess delivery, as the accelerated medium
continues moving on account of its own inertia even when the delivery stroke has
already ended.
• to prevent siphoning when the suction pressure is higher than the pressure system.
Safety and pressure relief valves protect the dosing pump and the associated accessories
and lines from overloads. They prevent an impermissibly high increase of pressure on
NOTICE!
