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High Flow Rate Dosing Pump

High flow rate metering pump with low level cut-off AT4-BL

The AT4-BL is a high flow rate dosing pump with a low level cut-off.  The maximum output of the AT4-BL is 60.0 litres per hour and is manually adjustable to suit a wide range of dosing applications.

AT4-BL High Flow Rate Dosing Pump Introduction

The AT4-BL is a high flow rate chemical dosing pump, designed to precisely dose chemical reagents into a process.  The AT4-BL delivers a constant flow rate which is manually adjustable using the front mounted potentiometer.

The AT4-BL chemical dosing pump is designed to deliver a larger volume of chemical reagent for larger volume requirements in the water-treatment, wastewater treatment, effluent treatment and process control applications.  The AT4-BL is suitable for applications where concentrated chemical reagents are used with wetted parts to suit.  The AT4-BL also includes a special low dosing mode, although another of our manually adjustable dosing pumps may be a better fit for low dosing applications.

In addition to the manually adjustable dosing rate, the AT4-BL has a digital volt free input which can be used to start or stop the pump.  This signal most commonly comes from a Low Level Float Switch or Suction Lance Assembly.  It's designed so that if a low chemical level is detected by the float switch, the pump will automatically stop running.

The AT4-BL can be attached to a flat vertical surface for surface mounting installation or used with the optional foot-mounting bracket for foot mounting applications.  Designed primarily for water treatment, wastewater treatment, effluent treatment and process control, the AT4-BL is a simple and reliable dosing pump for general applications.

The AT4-BL is powered from a switch mode power supply, suitable for a mains supply of 100 - 240 VAC 50hz or 60Hz.

AT4-BL Dosing Pump Outputs

The AT4-BL dosing pump series are available with the following outputs:-

Model Number*Output (Litres / Hour)Pressure (Bar)Speed (Strokes / Min)Output (mls / stroke)Hose Size (mm)Power (Watts)
AT4-BL-05-20 0 - 20.0 5.0 300 1.11 8 x 12 25
AT4-BL-03-30 0 - 30.0 3.0 300 1.66 8 x 12 25
AT4-BL-02-40 0 - 40.0 2.0 300 2.22 8 x 12 25
AT4-BL-01-60 0 - 60.0 0.5 300 3.33 8 x 12 25

AT4-BL Method of Operation

The AT4-BL is incredibly simple to operate, the pump has an On/Off toggle switch to locally control the pump, and with power applied to the dosing pump and the switch turned to on, the AT4-BL will begin metering chemical into a process at a desired rate using the front mounted potentiometer.

The AT4-BL also includes a selector switch which allows the metering pump to be entered into low dosing mode.  The low dosing mode restricts the output to a maximum of 20% of the pumps rated output.  If you're looking for a lower output dosing pump, it may be advisable to look at our other manually adjustable dosing pumps.

When the AT4-BL is drawing chemical from a chemical container, an optional suction lance assembly or float switch can be used.  This supplies a volt free contact to the dosing pump, preventing it from operating when the chemical container level is low.

The pump can either be directly connected to a mains supply voltage or switched on using the relay output from a piece of control equipment, such as a pH controller, cooling water controller or other piece of process control equipment.

With a fixed stroke length, the flow rate of the pump can be reduced using the front mounted potentiometer which adjusts the stroke frequency and therefore ensures precision control of the flow rate.

Priming the dosing pump couldn't be simpler.  The AT4-BL has an adjustable bleed valve located on the pump head and using the supplied tubing, the pump can be primed by allowing the chemical to circulate through the pump head to ensure that the pump is ready to accurately dose chemical into a process.

Designed to IP65 specification the AT4-BL is suitable for indoor or outdoor operation and can be foot mounted or surface mounted to a flat vertical surface.  Power is via a switch mode power supply, meaning that an AC supply voltage of 100 - 240 Volts at 50Hz / 60Hz can be used to power the pump.

AT4-BL Wetted Parts / Liquid End

The AT4-BL is designed as a high flow rate chemical metering pump for industrial usage and as such has wetted parts developed specifically for chemical handling.

As standard the AT4-BL is available with a liquid end manufactured in either PVC or PVDF, with Ceramic or PTFE balls and a PTFE diaphragm.  The seals and O-rings are available in either Viton (© DuPont / Chemours) or EPDM with PTFE O-rings available as an option.

  • Head Material

    The wetted parts of the pump head are manufactured in PVC or PVDF.

  • Double ball valves

    Double union ball valves are manufactured in PVC or PVDF with Ceramic or PTFE balls 

  • Diaphragm

    The diaphragm is manufactured in PTFE.

  • Injection Valve

    The injection valves are manufactured in PVC or PVDF

  • Foot Valve & Strainer Valve

    The foot valve and strainer assembly is manufactured in PVC or PVDF

  • Seals & O-Rings

    The seals and O-Rings are manufactured in VitonEPDM or PTFE.

Our chemical compatibility database can be used to check the wetted parts.  Please don't hesitate to get in touch if you are unsure.

What's in the box with the AT4-BL?

The AT4-BL is supplied complete with everything required to begin metering chemical reagents into a process.

Supplied with the dosing pump itself are:-

  • Injection Valve with 3/8" and 1/2" BSP male threaded connections
  • Foot-valve & Strainer assembly
  • 1 metre of discharge tubing
  • 2 metres of suction / bleed tubing
  • Surface mounting kit

An optional foot mounting bracket can be included for no additional charge if requested.

AT4-BL Features & Benefits

The AT4-BL is a robust, reliable and accurate chemical dosing pump designed for most general process control applications in the water treatment, effluent treatment or process control sectors.  The AT4-BL is ideal for either stand alone operation or integration with process control equipment where output control relays provide a control loop for process automation.

The AT4-BL includes a volt free input which can be used to start / stop the pump.  This is most commonly connected to a Low Level Float Switch or Suction Lance Assembly and prevents the metering pump from operating when a low chemical level is present.

Designed specifically for chemical metering the AT4-BL is fitted with wetted parts suitable for many chemical reagents, with a liquid end manufactured in PVC or PVDF, a PTFE diaphragm, Ceramic or PTFE balls and either Viton, EPDM or PTFE seals and O-rings.  Designed to IP65 specification, the AT4-BL is suitable for mounting outside.

The AT4-BL is available as the following model types:-

  • AT4-BL-05-20 for an output flow rate of 20.0 Litres / Hour at 5.0 Bar pressure
  • AT4-BL-03-30 for an output flow rate of 30.0 Litres / Hour at 3.0 Bar pressure
  • AT4-BL-02-40 for an output flow rate of 40.0 Litres / Hour at 2.0 Bar pressure
  • AT4-BL-01-60 for an output flow rate of 60.0 Litres / Hour at 0.5 Bar pressure

As the AT4-BL series are powered from a switch mode power supply, able to accept a mains supply of 100 - 240 VAC at 50Hz / 60Hz, ensures that the AT4-BL is compatible with export markets.

As part of our Red Dosing Pump range, the AT4-BL is rated hot for continuous dosing duty, and the pump is designed to provide a long trouble free life of precision chemical dosing.

AT4-BL Specifications

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  • Specifications


    High Flow Rate Manually Adjustable Dosing Pump

    Model Number:- AT4-BL

    Control Options:-

    • Constant Dosing With Manually Adjustable Output
    • Volt Free Input for automatic stop / start. (Low level float switch input)

    Frequency:- Max 300 Strokes / Min

    Liquid End Materials:- PVC or PVDF

    Diaphragm Materials:- PTFE

    Valve Housings:- PVC & Ceramic, PVDF & Ceramic, PVDF & PTFE

    Seals & O-Rings:- Either Viton, EPDM or PTFE

    Input / Output Connections:- 8 x 12 mm tubing


    • AT4-BL-05-20:- 0 - 20.0 Litres / Hour at 5 Bar Pressure
    • AT4-BL-03-30:- 0 - 30.0 Litres / Hour at 3 Bar Pressure
    • AT4-BL-02-40:- 0 - 40.0 Litres / Hour at 2 Bar Pressure
    • AT4-BL-01-60:- 0 - 60.0 Litres / Hour at 0.5 Bar Pressure

    Power Consumption:- 25 Watts

    Pump Body:- Designed to meet IP65

    Mains Supply:- 100 - 240 VAC 50Hz / 60Hz

    Supplied with:- 

    • Surface Mounting Bracket
    • Injection Valve
    • Foot-valve & Strainer Assembly
    • Discharge tubing
    • Suction tubing / Bleed tubing
    • Optional foot mounting bracket
  • Ordering Information


    Model Number*Output (L / Hr)Pressure (Bar)Liquid EndSeals & O-rings
    AT4-BL-05-20-PVC-V 0 - 20.0 5.0 PVC Viton
    AT4-BL-03-30-PVC-V 0 - 30.0 3.0 PVC Viton
    AT4-BL-02-40-PVC-V 0 - 40.0 2.0 PVC Viton
    AT4-BL-01-60-PVC-V 0 - 60.0 0.5 PVC Viton
    AT4-BL-05-20-PVC-E 0 - 20.0 5.0 PVC EPDM
    AT4-BL-03-30-PVC-E 0 - 30.0 3.0 PVC EPDM
    AT4-BL-02-40-PVC-E 0 - 40.0 2.0 PVC EPDM
    AT4-BL-01-60-PVC-E 0 - 60.0 0.5 PVC EPDM
    AT4-BL-05-20-PVDF-V 0 - 20.0 5.0 PVDF Viton
    AT4-BL-03-30-PVDF-V 0 - 30.0 3.0 PVDF Viton
    AT4-BL-02-40-PVDF-V 0 - 40.0 2.0 PVDF Viton
    AT4-BL-01-60-PVDF-V 0 - 60.0 0.5 PVDF Viton
    AT4-BL-05-20-PVDF-E 0 - 20.0 5.0 PVDF EPDM
    AT4-BL-03-30-PVDF-E 0 - 30.0 3.0 PVDF EPDM
    AT4-BL-02-40-PVDF-E 0 - 40.0 2.0 PVDF EPDM
    AT4-BL-01-60-PVDF-E 0 - 60.0 0.5 PVDF EPDM

    Viton (© DuPont / Chemours)

    For PTFE options please call.


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