How to Read a Dosing Pump Selection Manual: Curves, Tables and Notes

Many buyers open a dosing pump selection manual, turn to the model table, pick a model whose flow and pressure look big enough and place the order. On site they find the materials do not resist the chemical, the stroke has to be set so low that accuracy suffers, or the pump cannot lift from the tank. A dosing pump selection manual contains all of this information, but it is spread across different pages. This guide is brand-neutral and explains how to read a typical manual. For one specific brand, see reading the Milton Roy selection manual.

What a Dosing Pump Selection Manual Contains

Layouts vary, but a dosing pump selection manual usually includes:

1. Product range and application scope.
2. Model tables: flow, pressure, stroke rate, motor power, connection sizes.
3. Performance curves: flow against pressure and flow against stroke length.
4. Chemical compatibility tables for pump head, diaphragm, balls and seals.
5. Model code key explaining each digit.
6. Dimension drawings and installation requirements.
7. Notes and limits: suction lift, viscosity, temperature, back pressure.

Start With the Model Table

The table is where the search begins. Keep in mind:

• Listed flow is normally rated flow at maximum stroke, maximum rate and rated pressure.
• Listed pressure is the maximum allowed discharge pressure, not a recommended operating point.
• Flow varies with pressure, even if the table shows one figure.
• Watch the units. Many manuals show both L/h and GPH.

The table narrows the choice but does not decide it. See how to read a metering pump selection table.

Then Check the Performance Curves

Flow Versus Pressure

Pressure on the horizontal axis, flow on the vertical. Flow drops slightly as pressure rises. Read the actual flow at your working pressure.

Flow Versus Stroke Length

Stroke length percentage against flow. At low stroke settings the curve is often not linear and accuracy drops. Every dosing pump selection manual recommends a minimum stroke length. Make sure your normal flow sits on the straight part of the curve.

Use the Stroke and Frequency Chart

Some manuals list combinations of stroke length and stroke rate with approximate flows. Find your required flow, then pick a combination with moderate stroke length and a rate that is not too high for good accuracy and low wear. At high rates, viscous liquids cannot reseat the balls in time and flow drops.

Always Check the Compatibility Table

Compatibility tables list chemicals against materials for head, diaphragm, balls, seats and seals, rated as recommended, acceptable or not recommended. In any dosing pump selection manual:

1. Check every wetted part, not just the head.
2. Note concentration and temperature, because ratings change with both.
3. For blends, check each component or ask the manufacturer.

See pump head and valve ball materials for selection logic.

Do Not Skip the Notes Page

The notes often decide whether the pump works on site:

• Maximum suction lift: exceed it and the pump will not prime. Switch to flooded suction.
• Viscosity limits and the need for lower rates or special valves.
• Liquid temperature range.
• Minimum back pressure. Below it, flow runs high.
• Gassing liquids such as sodium hypochlorite need a degassing head.

Reading the Model Code Key

The code key turns your choices into an orderable part number. Each position stands for something: series, flow size, liquid end material, diaphragm, valve type, connection style, voltage and frequency, control options and sometimes accessories. Read the footnotes under the key, because some combinations are not allowed, for example a high-pressure head with large plastic connections. Leaving a position blank, or guessing it, is how pumps arrive with the wrong voltage or the wrong tube fittings. When in doubt, write out the code position by position next to the selection data and have the supplier confirm it before the order is placed. Keep the confirmed code with the project records for future spares.

Dimension Drawings Matter Too

Dimension drawings are easy to ignore, yet they decide whether the pump fits and how the pipes connect. Check overall size, bolt pattern, inlet and outlet positions and connection standards against the dosing room before ordering, so nothing arrives that cannot be installed.

The Order to Read a Dosing Pump Selection Manual

Work through the dosing pump selection manual in this order. Calculate required flow and pressure from the process, then shortlist models from the table. Check the curves to confirm flow at actual pressure and that normal flow sits in a sensible range. Check compatibility to set head, diaphragm and valve materials. Finally read the notes for suction lift, viscosity, temperature and back pressure. When everything matches, build the full model code from the code key. For flow calculation, see metering pump flow formula.

Common Errors When Using a Dosing Pump Selection Manual

The usual mistakes are reading rated flow as normal flow, checking only the pump head material, ignoring temperature in the compatibility table, skipping the suction lift limit, and leaving out options in the model code so the wrong voltage or connection arrives. A short checklist built from the dosing pump selection manual, ticked off for every enquiry, prevents most of them. Keep the completed checklist with the order so anyone can see later why that model was chosen.

FAQ

Can I use rated flow directly?

Rated flow is a maximum. Leave margin so normal flow sits in the middle of the range.

My chemical is not in the compatibility table. What now?

Ask the manufacturer, giving composition, concentration and temperature.

The curve and table disagree. Which is right?

The table shows rated conditions and the curve shows variation. Use the curve and your real conditions.

How do I write the model code?

Fill each position from the code key: series, flow, head material, valves, power supply and options.

Who can help if the manual is unclear?

Send your process data to the manufacturer or supplier and ask them to confirm the selection.

Conclusion

Reading a dosing pump selection manual means combining the model table, performance curves, stroke and frequency chart, compatibility table and notes page, then checking flow and pressure, curves, materials and limits in order. Browse our solenoid metering pumps, or contact us for manuals and selection support.