Determining Pump Capacity - ProMinent EXtronic EXBb Operating Instructions Manual

Tightening torques

9.1 Determining pump capacity

CAUTION!
After 24 operating hours, re-tighten the screws on
the dosing head.
Data
Tightening torques for M4 screws:
Tightening torques for M5 screws:
The actual pump capacity depends on stroke length, stroke rate
and back pressure in the metering line. The relationship between
pump capacity/stroke length/stroke rate is depicted in a nomograph
for each pump type. The diagram, which shows how the pump
capacity changes in the event of back pressure, includes a correc‐
tion factor (the nomographs can be found at the end of the oper‐
ating instructions).
The measurements to produce the nomographs were taken using
water and the correction factor is calculated with a stroke length of
70 %. The spread of pump capacities across all material versions
is –5 % (for maximum: no details).
1. Select the desired pump capacity from the value of ranges
for the pump type - see performance data.
2. Select the nomograph and diagram of the pump type.
3. On the diagram's X-coordinate, mark the back pressure in
the metering system and read the associated correction
factor off the X-axis.
4. Divide the desired pump capacity by the correction factor.
5. Use a ruler to mark the calculated pump capacity on the
centre scale of the nomograph.
6. Draw a line across all three scales. Make it as horizontal as
possible, ensuring however that at least one of the two outer
scales is intersected; in so doing, wherever possible select a
scale marking with a large value on the stroke length scale.
The point at which the line intersects with the right-hand scale indi‐
cates the stroke rate to be set, the point at which the line intersects
with the left-hand scale indicates the stroke length to be set.
Start up
Value Unit
2.5 ... 3.0 Nm
4.5 ... 5.0 Nm
33