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Chemical Metering Pumps Made in the USA!

Chemical Metering Pumps - Three Pump Series

JN10-A Chemical Metering Pump

MF Series Chemical Metering Pump
MH Series Chemical Metering Pump


Madden diaphragm chemical metering pumps are designed for tough jobs where chemicals must be accurately pumped all day long, year round. 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.


Repeatable accuracy of +/- 1% over a 10:1 turndown ratio is maintained with the stroke adjustment control located conveniently on the top of the chemical metering pump.

Long Life, Low Upkeep

The simple mechanically actuated diaphragm design eliminates irritating hydraulic systems and packing glands used in many chemical metering pumps. Large bearings and shafts, continuously lubricated with a bath of oil give many years of dependable service. Precision bronze worm gears and steel worm drive shafts convert motor rpm's to linear piston pumping power. Replacing worn parts is quick and easy, and accomplished with common tools.

Chemical metering 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...
  • Heavy-duty aluminum gear box and pump body castings
  • Precision machined and bolted assembly
  • Wetted end parts made from a selection of corrosion resistant material.
  • Thick Nylon reinforced diaphragms for tough pumping service.
  • Industrial grade 56 frame electrical motors are available to meet any enclosure and power supply requirement.

Why use a Madden chemical metering pump?

… It will be the work horse of your chemical metering system.
Chemical metering pumps
Chemical Metering Pumps

Chemicals are added to many processes in industrial plants to produce a desired outcome, such as changing the pH of water. Adding too much of the chemical will waste money and it could also reduce the desired outcome that was required in the first place. A chemical metering pump is designed to enable the operator to control the rate of chemical addition to ensure the results are within the limits of the specifications for the process.

Safety Features

Type DDB Double Diaphragm

Madden's Type DDB Double Diaphragm construction is a feature in our chemical metering pumps meant to minimize/eliminate the dangers and potential losses that result from a rupture or leak in the pump system. When chemical metering applications arise for a corrosive and dangerous chemical they are not only harmful to human skin, they can be extremely corrosive to metals, rubbers, and other materials found in the plant. When dealing with corrosive chemicals like this, parts fatiguing on the pump is inevitable and a potential leak or rupture in the pumping system can have dangerous and costly consequences. Madden's Type DDB Double Diaphragm is an added safety feature on 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 DDB’s 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 chemical metering pump single primary diaphragm construction JN series chemical metering pump type DDB double diaphragm construction
Standard, single diaphragm design Type DDB double diaphragm design

Our chemical metering pump's double diaphragm construction

The DDB double diaphragm construction design adds a spacer and another, backup/secondary diaphragm to the chemical metering pump’s wetted end to ensure the corrosive chemical, like caustic soda, never reaches inside and damages the pump’s interior components. This added feature is one of the reasons there are Madden chemical metering pumps still in service after 25 years of operation. The Type DDB double diaphragm is just another way Madden ensures their product is focused on simple, rugged quality.

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

Metering pump leak detecting pressure switch

Chemical injection pump pressure switch location Leak detecting pressure switch
The DDB double diaphragm has the ability to place a pressure switch in the spacer between diaphragms via a 1/4” NPT hole in the spacer to detect a potential leak or rupture in the pumping system to prevent dangerous and costly consequences.

Under normal operating conditions the pressure inside this spacer is the same as the ambient air surrounding it. With that being said the pressure switch should be set to the lowest pressure setting so that if any kind of rupture occurs in the pump’s primary diaphragm, the smallest amount of pressure build up that results will set off the pressure switch. From that point you can either wire it to an alarm or wire it to shut off the motor; making absolutely certain 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 chemical metering pump, download the pump selection guide, complete the form and upload it in the RFQ section of our website. We take pride in responding promptly!
Metering Pump Selection Guide

Chemical Metering Pumps - Three Pump Series - Made to Order

Madden Manufacturing doesn’t just manufacture chemical metering pumps. We also put together entire chemical metering 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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