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Accuracy That Pays for Itself

Chemical is one of the largest running costs of any treatment plant, and over-dosing wastes reagent while under-dosing breaches consent. Precision dosing — the right metering pump, properly calibrated and held on target by the control loop — keeps the dose where the chemistry needs it. We specify pumps for the duty, verify accuracy on commissioning, and design in the turndown so the system stays precise across the full flow range.

Overview

What Precision Dosing Delivers

Precision is more than a headline accuracy figure. It is repeatability shot-to-shot, linearity across the turndown, and stability as suction conditions, viscosity and back-pressure change. We select diaphragm, peristaltic or progressive-cavity pumps to match the reagent and duty, size them with margin without sacrificing low-flow resolution, and calibrate against a measuring cylinder or calibration column on site so the displayed dose is the delivered dose.

±1% Accuracy

Metering pumps specified and calibrated to deliver the set dose within ±1% across the working range.

Wide Turndown

Pump and control sized so dosing stays precise from minimum night flow to peak.

Repeatability

Consistent, pulse-managed delivery shot-to-shot for stable downstream chemistry.

Verified on Site

Calibration columns and bench checks confirm delivered volume against the set point.

What Undermines Dosing Accuracy

The Failure Modes We Design Out

A metering pump rated to ±1% in the catalogue will not hold it on site unless the whole system is right. These are the issues we engineer out.

Gassing & Vapour Lock

Hypochlorite and other gassing reagents lose prime — degassing valves and the right pump head keep delivery true.

Back-Pressure Swings

Loading valves and pressure-relief hold a stable head so output does not drift with system pressure.

Viscous & Abrasive Reagents

Lime and polymer need pump types that handle solids and viscosity without losing accuracy.

How It Works

How We Achieve and Hold Precision

1

Define the Dose

The target dose comes from stoichiometry or jar testing, converted to a pump output with the dosing equations.

2

Select the Pump

Pump selection matches reagent, flow, pressure and turndown to the duty.

3

Manage the Suction

Calibration column, degassing and flooded suction keep the pump primed and linear.

4

Control the Output

The control loop flow-paces and trims the dose as conditions change.

5

Calibrate

On-site calibration verifies delivered volume against the set point.

6

Verify in Service

Residual or analyser feedback confirms the dose is achieving its treatment target.

Accuracy & Turndown by Pump Type

Indicative performance we design to

Pump typeTypical turndownAccuracyBest for
Solenoid diaphragm10:1±2–3%Small, clean-reagent duties
Motor-driven diaphragm100:1±1%General coagulant / acid / alkali
Peristaltic100:1±1%Gassing, abrasive (lime, hypochlorite)
Progressive cavity50:1±1–2%Viscous polymer solution

Related Equipment & Tools

Plant and tools for this duty

Dosing Pump Selection

Diaphragm, peristaltic and progressive-cavity pumps matched per reagent and duty.

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Packaged Dosing Skids

Pump, calibration column, control and containment factory-built and wet-tested.

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Dosing Equations

Convert target dose to pump output for flow, strength and SG.

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Dose Calculator

Size dose rate, pump capacity and chemical consumption online.

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Key Benefits

Why Choose Reynolds & Bauhm

Metering pumps specified and calibrated to ±1% on site
Wide turndown so precision holds from night flow to peak
Pump type matched to gassing, viscous or abrasive reagents
Degassing and back-pressure control to stop output drift
Lower chemical spend through accurate, repeatable dosing
Calibration columns for verifiable delivered volume
Control-loop trim that holds the dose on target
Commissioning records proving achieved accuracy

Related Pages

Explore the Dosing Knowledge Hub

Dosing Pump Selection

The right pump sets achievable accuracy and turndown.

Read More

Dosing Control Strategy

Flow-paced and residual-trim control to hold the dose.

Read More

Flow-Proportional Control

Demand-based dosing from real-time flow and sensors.

Read More

Chemical Dosing Systems

Back to the dosing systems overview.

Read More

Need a precision dosing solution?

Our engineers size storage, pumps, injection, control and containment to your measured duty — then build and commission it.

Industries We Serve

Our expertise spans multiple industries with sector-specific water treatment solutions.