Corrosion Testing Procedures
Manufacturing a chemical means making the users feel comfortable about the product. We are both proud and certain that Dynamic Descaler is a well produced product that is now being used around the globe.
We take pride in both the longevity and low corrosion rates of our Dynamic Descaler and we will challenge any and all competitors in this area. Since early 1940 one competitor who has been well established still states that their product is non-corrosive. One must ask, “who has any experience in chemistry”, how this is possible if their product has over 2.9% of hydrochloric acid in its makeup?
We test the Dynamic Descaler on a regular basis. We use the same procedure as the US Navy using the guidelines of ASTM G31 which consists of using 0.75″ X 2″ X 0.125″ coupons. The coupons range from 90/10 to 70/30 copper nickel. Most heat exchangers, condensers and evaporators have this type of copper used. The coupons are ordered from Metal Samples in Munford, Alabama, United States which is the same source used by the US Navy.
The procedure is as follows:
- We place one of the pre-weighted coupons in a 500 ml beaker with 450 ml of Dynamic Descaler solution. The pre-weight is the pre-test weight.
- The coupon is submersed for six hours and is held by a holding support
- After six hours the coupon is removed, and set to dry for one hour on a dry cloth.
- After drying the coupon is taken to an independent lab called the Manufacturer’s Testing Laboratory in Crowley, Texas, USA. Here the coupon is cleaned and rinsed and dried thoroughly by their procedures to remove any contaminants and weighed for a post-test weight. In this way a true “coupon only” weight is obtained after being submersed in Dynamic Descaler.
- The difference in weight indicates the corrosion. The coupon is weighed with an analytical balance to the nearest 0.1 mg. The weight is typically in grams.
- The weight difference is then converted into mills per year as follow using ASTM G-31: Corrosion Rate = (Constant K x Mass in grams) / (Area in cm2 A x Time in hours T x density in grams/cm3 D) or (K x W)/ (A x T x D). Corrosion Constant K is 3,450,000 for mills per year (mpy). Other constants for K are 3,450 for inches per year (ipy), and 87,600 for millimetres per year (mm/y).
If your company is using a descaler and the manufacturer states that it has up to 10% of HCl (hydrochloric acid), (usually stated as less than10% Hcl on a material safety data sheet) and implies that it is non-corrosive, you need to have an independent lab conduct a corrosion test on the product as soon as possible for both the safety of your employees and to your equipment.