The common selection error is sizing a dosing pump for peak demand. Dosing pumps spend most of their life well below peak, and that is where accuracy is lost.
The Operating Reality
A dosing skid feeds one or more chemicals into a water line at low flow, against backpressure that varies with the process.
Why It Matters
A pump sized for peak runs at a small fraction of stroke at normal dose, where repeatability degrades. Sizing for the working dose with margin keeps the pulse rate high and the dose repeatable.
How It Works in Practice
- Imported plunger metering pumps deliver ±0.5% accuracy against a national standard of ±3%, with pulse rates above 5000 per minute for fine control.
- Match wetted parts (316L, PVC, PVDF, PTFE) to every chemical to be fed, not just the first one.
- Provide dry-running protection and leak detection, and confirm the pump accepts the control signal (4-20 mA, pulse or fieldbus) the controller will send.
Selection Checklist
- Choose the control signal (pH, ORP, conductivity or flow-proportional) before sizing equipment.
- Size the metering pump to the working dose with margin, not to peak demand.
- Confirm wetted-part compatibility for every chemical to be fed.
- Require leak detection, dry-running protection and containment in the installation.
- Plan integration with PLC, DCS or remote telemetry from the start.
Related Products
- Automatic Chemical Dosing System
- Automatic Condenser Tube Cleaning System (ATCS)
- Constant Pressure Water Make-up System
FAQ
Related Dosing Guides
- Chemical Dosing System Working Principle
- Ro Pretreatment Dosing System
- Scale Inhibitor Dosing System
Explore more in our Chemical Dosing Systems →
Pingback: How an Automatic Chemical Dosing System Works
Pingback: Scale Inhibitor Dosing System
Pingback: Wastewater Treatment Dosing System