Watson-Marlow Qdos Metering Pumps

At Process & Power, we offer Watson-Marlow Qdos chemical metering pumps for applications that require accurate, repeatable and dependable chemical dosing.

Qdos pumps use peristaltic technology to meter chemicals without the valves, diaphragms or mechanical seals found in many conventional dosing pumps. The chemical remains contained within the pumphead fluid path, helping reduce maintenance requirements, chemical leakage and operator exposure.

Qdos pumps can be used for continuous or intermittent dosing in water treatment, wastewater treatment, chemical processing, food and beverage production, mining and other industrial applications.

Accurate Chemical Metering

A Qdos pump moves a controlled amount of chemical with each rotation of the pumphead. This positive-displacement design provides predictable flow and helps maintain dosing accuracy as process conditions change.

Qdos pumps can help facilities:

  • Maintain consistent chemical dosing

  • Reduce overdosing and chemical waste

  • Improve process control

  • Simplify calibration

  • Reduce maintenance time

  • Minimize the risk of chemical leaks

  • Eliminate many conventional pump accessories

Qdos Chemical Metering Pumps

The standard Qdos range is designed for low- to medium-flow chemical metering applications. Different pumps and pumpheads are available to accommodate varying flow, pressure and chemical-compatibility requirements.

Qdos pumps are commonly used for:

  • Chlorination and disinfection

  • pH adjustment

  • Coagulant and flocculant dosing

  • Sodium hypochlorite dosing

  • Acid and caustic addition

  • Polymer dosing

  • Nutrient dosing

  • Process chemical injection

  • Cleaning chemical addition

Qdos H-FLO Metering Pumps

Qdos H-FLO extends Watson-Marlow’s Qdos technology into higher-flow chemical metering applications. It provides the same basic advantages of peristaltic chemical containment while supporting applications that require considerably more chemical volume.

Qdos H-FLO may be considered when a process needs:

  • Higher chemical feed rates

  • Accurate flow control

  • Reduced ancillary equipment

  • Fast pumphead maintenance

  • Secure chemical containment

  • Integration with plant control systems

ReNu Pumphead Technology

The replaceable pumphead is the primary fluid-contact component in a Qdos pump. This design allows maintenance personnel to replace the fluid-contact portion without dismantling valves, diaphragms or complicated wet-end assemblies.

Pumphead selection depends on the chemical, concentration, temperature, operating pressure and required flow rate. Process & Power can help verify chemical compatibility and identify the appropriate Qdos pump and pumphead for the application.

Why Choose Qdos Metering Pumps?

  • Accurate and repeatable chemical metering

  • Peristaltic operation without conventional valves

  • No mechanical seals in the fluid path

  • Reduced risk of clogging and vapor locking

  • Simplified installation

  • Quick pumphead replacement

  • Reduced maintenance requirements

  • Lower potential for chemical leakage

  • Flow control for continuous or intermittent dosing

  • Models available for different flow and pressure requirements

Contact Process & Power for Qdos Metering Pumps

Process & Power can help you select a Qdos chemical metering pump based on your required flow, discharge pressure, chemical concentration, temperature, control requirements and operating environment.

Located at: 1721 Corporate Avenue • Memphis, TN 38132
Call us at: (901) 362-5500

Watson-Marlow Qdos Metering Pumps FAQ

What is a Watson-Marlow Qdos pump?

A Qdos pump is a peristaltic chemical metering pump designed to deliver controlled and repeatable flow. It uses a replaceable pumphead instead of the valves, diaphragms and mechanical seals found in many conventional metering pumps.

How does a Qdos metering pump work?

Rollers inside the pumphead compress an internal fluid path to move a measured amount of chemical through the pump. The pumped chemical remains contained within the pumphead and does not contact the pump’s drive mechanism.

What is the difference between Qdos and Qdos H-FLO?

Standard Qdos pumps are intended for lower-flow chemical metering applications, while Qdos H-FLO extends the technology into higher-flow duties. The correct model depends on the required flow, pressure, chemical and control method.

Can Qdos pumps replace diaphragm metering pumps?

In many applications, yes. Qdos pumps can eliminate components commonly associated with diaphragm pumps, such as valves, pulsation dampeners, degassing devices and other ancillary equipment. The complete application should be reviewed before replacing an existing pump.

Can a Qdos pump handle sodium hypochlorite?

Qdos pumps are commonly considered for sodium hypochlorite dosing because their peristaltic design does not use conventional valves that can be affected by gas formation or crystallization. Pumphead compatibility must still be verified for the chemical concentration and operating temperature.

What chemicals can Qdos pumps meter?

Depending on the selected pumphead, Qdos pumps can meter acids, caustics, disinfectants, coagulants, polymers and other treatment or process chemicals. Chemical compatibility should be confirmed for the exact fluid, concentration and temperature.

Why is my Qdos pump not delivering the correct flow?

Possible causes include an incorrectly selected or worn pumphead, improper calibration, restricted suction piping, excessive discharge pressure, air entering the suction line or changes in the chemical’s viscosity, temperature or concentration.

How often should a Qdos pumphead be replaced?

Pumphead life depends on the chemical, pressure, speed, temperature, operating schedule and installation conditions. Regular inspection and planned replacement can help prevent unexpected chemical leakage or dosing interruptions.

Does a Qdos pump require calibration?

Calibration helps the pump account for actual installation conditions and improves delivered-flow accuracy. The pump should be recalibrated following pumphead replacement or whenever operating conditions change significantly.

Can Qdos pumps communicate with a plant control system?

Available control options vary by model and configuration. Qdos pumps may support manual control, analog signals, contact inputs and industrial communication options. Process & Power can help match the pump’s controls to the facility’s automation requirements.

Can Process & Power help select and service Qdos pumps?

Yes. Process & Power can review the chemical, flow, pressure, temperature, piping and control requirements to help select the appropriate Qdos pump. We also provide troubleshooting, preventative maintenance and industrial pump support throughout the Mid-South.