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Proportioning Pumps

Proportioning - Three Pump Series

Madden pumps are ideal for injecting the correct proportion of chemical into an operating process, whether that process is water or waste water treatment, or extracting gold from ore in a mill. Madden diaphragm type proportioning pumps are industrial grade equipment designed to be used where chemicals must be pumped 24-7-365. Engineered materials are used for the wetted end to pump virtually any chemical, from acids to caustics. Even viscous liquids and suspended solids can be metered and pumped with precise accuracy.
JN10-A Pump

MF Series Pump
MH Series Pump

Madden diaphragm metering pumps are designed for tough industrial uses


Getting just the right amount of chemical added to the process requires a precision pump design. Repeatable accuracy of +/- 1% over a 10:1 turndown ratio is maintained with the stroke adjustment control located conveniently on the top of every Madden pump.


The Madden pump’s mechanically actuated diaphragm design makes irritating hydraulic systems and packing glands old fashioned. Continuously lubricated bearings and shafts are bathed in of to assure many years of dependable pumping service. The heavy duty diaphragm keeps the chemical from penetrating the inner gear works of the pump. And when it is time to replace worn wetted end parts the job is quick and easy and accomplished with common tools. Proportioning pumps by Madden are heavy duty, industrial grade, using standard industrial 56 frame motors and worm gear reducers to produce reliable chemical pumping power designed to provide years of dependable service.

Features include:
  • Four Pump Series
    JN Series Pump
    56 frame industrial motors
  • Valve check balls are available in Teflon, stainless steel, Hastelloy C and ceramic
  • Corrosion resistant materials include Teflon, 316 stainless steel, polypropylene and PVC.
  • Thick Nylon reinforced diaphragms for years of tough pumping service. Materials include Teflon faced, Viton, Hypalon, and Neoprene.
  • Motors are available in 50 Hz and 60 Hz power, with explosion proof, mill, and chem duty, and washdown duty enclosures available to meet the site requirements

How about automatic control for chemical proportioning?

Madden diaphragm metering pumps are available with a variable speed motor and controller which can automatically change pump output in response to a control signal. With an instrument, a pH sensor, for example, to generate a 4-20 mA control signal the motor speed can be changed to increase or decrease the amount of chemical being injected into the process. Contact your Madden sales representative to have your chemical proportioning done automatically.

Safety Features

Type DDB Double Diaphragm

When pumping corrosive and dangerous chemicals parts on the pump will inevitably fatigue. These chemicals can be extremely corrosive to metals, rubbers, and other materials found in the plant, as well they are harmful to human skin. A potential leak or rupture in the pumping system can have dangerous and costly consequences.

Madden's Type DDB Double Diaphragm construction is a feature meant to minimize/eliminate the dangers and potential losses that result from a rupture or leak in the proportioning pump. This is achieved by adding additional safety features to the pump to ensure the operator that the corrosive liquid will not enter the interior of the pump or leak on the shop floor. The dry mechanical design means never having to worry about hydraulic barrier fluids entering the application in the case of pharmaceutical and food applications.
JN series single primary diaphragm construction JN series type DDB double diaphragm construction
Standard, single diaphragm design Type DDB double diaphragm design

Proportioning Pump, Extra Protection

To ensure corrosive chemicals, such as caustic soda, never reach the inside and damage the pump’s interior components, the Type DDB double diaphragm construction design adds a spacer and another backup/secondary diaphragm to the chemical pump’s wetted end. When properly maintained Madden proportioning pumps have lasted for over 25 years with only minor wetted end parts needing to be replaced. Adding a Type DDB double diaphragm to your proprotioning pump will help add years of service life to your next Madden proportioning pump/system.

The pictures to the right is a Madden JN series pump with a standard, single primary diaphragm design, and a Madden JN series type DDB double diaphragm design.

Leak Detecting Pressure Switch

One Quarter Inch Hole Leak detecting pressure switch
The type DDB double diaphragm also comes with the ability to place a leak detecting pressure switch in the spacer between diaphragms. A 1/4” NPT hole is machined into the spacer that allows for a pressure switch to be installed. The pressure switch should be set to the lowest level. Under normal operating conditions the pressure inside the spacer is the same as the ambient air surrounding it. When the pressure switch is set to its lowest setting and there is any kind of rupture in the pump’s diaphragm, the smallest amount of pressure that results will set off the pressure switch. You can also wire the switch to an alarm or wire it to shut off the motor when a rupture is detected; giving you peace of mind that harsh chemicals such as sodium hydroxide will never touch the shop floor or anything else near the pump.

Madden Metering Pump Selection Guide

For the cleanest and easiest way to inquire about a Madden metering pump, download this fillable pump selection guide, fill it out, and upload it to the RFQ section of our website. We take pride in responding promptly!
Metering Pump Selection Guide

Proportioning - Three Pump Series - Made to Order

Madden Manufacturing doesn’t just manufacture proportioning pumps. We can also build entire pumping systems.
Made to order Chemical Metering Pumps Made to order Chemical Metering Pumps
Example 1 of a made to order system Example 2 of a made to order system

Click here to contact us to let us know what your requirements are and we'll see what we can do!

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Faster Lead Times than Neptune & Milton Roy

Madden Manufacturing is currently quoting lead times of:
  • Chemical Metering Pumps @ 1-2 weeks
  • Fully Assembled Chemical Feed Systems @ 3-6 weeks
  • Sample Coolers & Small Heat Exchangers @ < 1 week
  • Emergency/Rush pumps in 1-2 days!

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