Metering Accuracy - ProMinent gamma G/4b Operating Instructions Manual

Fine bleeding
Page 40 of 88 pages
Commissioning
• Start the pump with stroke length/stroking rate at 100% and discharge
line free of pressure by simultaneously pressing the
keys until the medium has completely filled the liquid end and
is free of bubbles. This can be verified by the medium being visible
in the discharge or bleed line.
• Close the bleed valve. The metering pump is ready to operate.
For media which slightly emit gases the fine bleeding (17) can be set
continuously for liquid ends with bleed valves:
• For this purpose after pulling off the attached star handle (17b) open
the screw (17a) inside the bleed valve with a screwdriver approx. 1 turn
anti-clockwise.
• This results in a partial flow of the metering quantity constantly being
returned to the supply tank!
• The backfeed quantity should be approx. 20% of the metering quantity!
• The media must be fluid and without solid particles.
Warning!
The above mentioned measures do not guarantee any
totally reliable metering after the pump has been idle! It is
essential that regular checks are carried out.
PLEASE NOTE:
If the backfeed line ends above the fluid level, the fine bleeding
valve operates as a vacuum breaker and prevents the supply
tank from being sucked empty if vacuum occurs in the discharge
line!
After approx. 24 operating hours the screws in the liquid end are
to be tightened crosswise.
Attention
It is essential that the torque for the screws is observed. Torque
for screws M4 : 2.5 - 3 Nm, M5 : 4.5 - 5 Nm.
11.4

Metering accuracy

All details are related to metering capacity measurements with water
at a temperature of 20 °C.
When conditions remain unchanged (same counter pressure, same
stroke length, stroking rate, operating temperature, mains voltage,
suction lift, medium temperature, same medium, and same diameter/
length/material of the line) the metering reproducibility is ≤ ± 2% during
short periods and for a stroke length setting of at least 30% in
accordance with the following instructions.
and
Version 2.0