Contaminant-Free Drinking Water? It’s More Than Just A Pipe Dream

What makes stainless steel ideal for use in water and wastewater services? It’s a great question, but the quicker one to answer would be: what doesn’t make stainless steel ideal, because the answer is – nothing! Stainless steel is quite simply the perfect material to use when it comes to piping and fittings for water-based applications.

There are many reasons for this. Stainless steel pipes are known for their durability and corrosion resistance. They don’t need any corrosion allowance or special coatings, but care should be taken when selecting the grade of steel for the job at hand. Different stainless steel grades have differing strengths and corrosion resistance, so make sure you select the grade most suited to the water and wastewater treatment or distribution application required. It’s also important to choose a reputable stainless steel manufacturer who uses good fabrication practices. Get both these aspects right, and you are guaranteed that the high performance you expect is achieved.

Grades 304L and 316L are the two most commonly used stainless steel grades by the water industry. Both are austenitic, meaning they’re strong, ductile and do not become brittle in freezing temperatures. In addition, 316L contain molybedenum, which offers higher corrosion resistance, making it ideal for more extreme and exacting conditions. A range of more highly alloyed “superaustenitic” alloys is available for critical applications.

Legislation on the treatment, storage and distribution of drinking water places strict limits on the levels of contaminants permitted in the water. Rigorous testing and research on behalf of the European Drinking Water Directive shows that any leaching of metallic elements from stainless steel piping is consistently well below permitted levels – sometimes as little as less than 5% of the stipulated maximums.

Much of this minimal leaching comes from new piping, and leaching levels are proven to decline even further over time as the pipes age. These low levels are not only good for drinking water, but waste water systems as well. Sewerage sludge left over from water treatment practices is often used for agricultural fertiliser, and high levels of metal content in the sludge make it unsuitable for this purpose.

Steelmor is one of the leading stockists and manufacturers of stainless steel products in the country, and boast the most comprehensive stainless steel stockholding and manufacturing facilities in Southern Africa. Talk to us today about how we can help you with your next water piping project.