Anticorrosive Mechanism for Assembling Corrugated Metal Pipes by Meiyi

Hot dipping galvanizing is commonly adopted to process pipe joints and plates of corrugated metal pipes in China. With an average thickness of over 84μm, the galvanized layer can protect pipes from corrosion in a service life of 60-80 years without soaking in the saline water or hazardous industrial waste water. According to the survey, the thickness of the ungalvanized metal pipes can be generally corroded by 0.01 to 0.03mm per year. Domestic factories perform more conservatively in pipes production by adding 0.5mm to the thickness for a longer service life of 25-50 years. Besides, pipes will be asphalted twice after being transported to the site, which also adds 0.4-0.5mm to the thickness, increasing the service life by 5 to 15 years. In addition, technical parameters (such as corrugation size and thickness) can be flexibly adjusted based on the occasional overload of transportation in China to ensure the security. Therefore, the service life of corrugated metal pipes in China can reach or exceed 100 years.

            

In 1978, American Iron and Steel Institute (AISI) conducted a study on 81 corrugated metal pipes applied as storm sewers. The research showed that the majority of those pipes were in good condition with a service life of 65 years

In 1986, National Corrugated Steel Pipe Association (NCSPA) conducted a co-study with AISI on corrugated metal pipes used as drainage pipes. The result demonstrated that these pipes could perform as long as 74 years, and even approximately 100 years under certain soil and water conditions.

In 1993, 21 pieces of structural plates and galvanized in-walls of pipes installed for over 20 years were tested in British Columbia. It was estimated that those pipes except for 2 enjoy a service life exceeding 100 years.

According to one latest international report, the average service life of corrugated metal pipes is 81 years.