Diaphragm Type Metering Pumps Chemical Feed Systems

Another harsh chemical that Madden pumps commonly handle is sulfuric acid.

Background of Sulfuric Acid

Sulfuric acid is predominately used in the production of fertilizers and manufacturing of chemicals. It is also commonly used for pH control of water. If you would like to know more about sulfuric acid, Pubchem has a simple write up on this chemical which you can read by clicking on this link.http://pubchem.ncbi.nlm.nih.gov/compound/sulfuric_acid

The Recommendation Process

At Madden we rely on a combination of documentation and experience. The documentation includes checking the chemical resistance of wetted end parts using at least three different charts to verify that the diaphragm, valve seats, valve balls, and so on will hold up to the chemical being pumped. However, just looking at charts isn’t always the best route. There are 3 individuals with 20+ years of experience each at Madden and you can’t replace experience. We also rely on customer experience as well. There are some times where a chart will claim a material will hold up to a certain liquid and end users tell us this simply isn’t true. They see it in use and in the field and we adjust to this information. The opposite can be true as well; on occasion an end user will relay information to us stating even though material X is generally stated as something that can’t hold up to the liquid, they have never had a problem.

Quick Guide

Sulfuric acid has several levels of concentration; the level of concentration in the process being pumped will determine the most cost effective way to design a pump to handle the liquid. If you are pumping sulfuric acid and are interested in inquiring about a Madden pump, make sure to double check on the concentration. Lower levels may allow for more economical wetted end parts to be used, rather than some of the more expensive higher end parts.
But, because our recent blogs have been focusing on harsh chemicals, let’s take a look at Sulfuric Acid with a 95% concentration. The following is a common wetted end we would prescribe for a customer’s application:

Solution Head: Teflon
Diaphragm: Viton (or Teflon faced Viton, if necessary)
Valve Seats: Viton
Valve Check Balls: Teflon (or Viton, Alloy 20, and Hastelloy C if necessary)

Also, for corrosive or dangerous chemicals like sulfuric acid, Madden always recommends a double diaphragm set up. This backup diaphragm essentially ensures that the chemical will never come in contact with the interior parts of the pump; allowing repairs to be minimal when and if needed.


If you have a need to inject chemicals into another fluid give us a call (574-295-4292) or request a quote. We’ll work with you to find the best pump that will last as long as possible and keep your process running smoothly 24/7/365. And don’t forget to check out our sales reps, odds are there is a rep in your back yard.