The data required for selecting an progressive cavity pump is of utmost importance.
The performance data shown as below must be used as a guide only and they are referred to product similair to cleaning water at 20°C.
In order to select the right pump model it is necessary to know the following data:
1. capacity-flow rate: lt/min – mc/h.
2. outlet pressure: bar or m.W.S
3. suction pressure: positive/flooded suction – negative suction lift m.W.S
4. viscosity: cP – Pa*s of the medium
5. specific gravity of the medium: kg/dm3 – percentage – max diameter of solid parts
6. working temperature of the medium: C°
7. kind of abrasion: ex:
- non abrasive liquids: water, emulsion water and oil, wine etc
- low abrasive liquids: dirty water, biological sludge etc
- abrasive liquids: slurry, lime milk
- high abrasive liquids: heavy slurries – emery sludge, dewatered sludge – cement with high sand concentration
8. corrosion: PH, acid concentration, temperature.
Data referred to Water 20°C with pressure at 0 bar
Pump speed is in relation to the type of medium being pumped.
Relation above all refers to the abrasion and the viscosity of the medium.
Therefore, abrasive wear of progressive cavity pumps can be improved by decreasing pump rotational speed and by increasing the number of pump stages.