Why can’t carbon steel elbow contact water?

The elbow is made of cast iron, stainless steel, alloy steel, malleable iron, carbon steel, non-ferrous metal and plastic. Elbow connection methods are: direct welding (the most commonly used way) flange connection, hot melt connection, electric fusion connection, threaded connection, socket connection.

Carbon steel elbows are divided into 45 ° and 90 ° according to the angle, and other special-shaped elbows such as 60 ° are also included according to the needs of the project. It is a metal pipe fitting that changes the direction of the pipe on the carbon steel pipe.

Do you know why can’t carbon steel elbow contact water?

ASTM A234 Gr WP91 ANSI B16.9 180 degree pipe elbows

ASTM A234 Gr WP91 ANSI B16.9 180 degree pipe elbows

Carbon dioxide is a kind of impurity in water, which exists in free form under normal conditions. When the pH value is low, many bicarbonates in water also exist in the form of free carbon dioxide, so the problem of average carbon dioxide will appear.

If carbon dioxide enters the desalinated water, the conductivity of the water will be added and the corrosivity will be added. Therefore, measures should be taken to prevent CO2 from dissolving into the water tank. For example, the use of nitrogen or other inert gas to protect the top space of the water tank can prevent CO2 from polluting the purified water.

Therefore, the more carbon dioxide in water, the more H + generated, the lower the pH value of water, acid corrosion water, damage the protective film formed on the surface of carbon steel, leading to carbon steel corrosion.

Haihao Group manufacture elbow products more than 30 years,the products sells well all over the world for the high quality. If you have any question,please contact us! Email:sales@haihaogroup.com