are steel pipes that have been hot-dipped in a protective zinc coating to prevent corrosion and rust (the process is called “hot dip galvanization”). Galvanized pipes were introduced in the sixties as an alternative to lead pipes for water transmission and distribution. After that, they have been used also for sewerage applications, firefighting, and general plumbing systems.
During the galvanization process, the zinc coating applies both to the outside and the inside of the pipe. The standard zinc coating is between 1.6 and 1.8 oz per square foot.
Galvanized pipes show long-lasting durability, improved resistance to corrosion compared to standard black steel, and are available at a relatively cheap price (and good toughness) compared to alternative metals (the price of galvanized pipe vs copper may be, to give a general indication, 6 times lower per metric ton).
As a rule of thumb, the galvanized price is between 40 and 50% higher than the price of black carbon pipes (the application of a zinc coating requires the transportation of the bare pipe to the galvanization plant, the application of zinc raw material on the pipe and other finishing activities).
On the other side, galvanized pipes are heavy, difficult to repair and tend to develop blockages over the course of time (the internal part of the pipe is subject to corrosion, and it’s not infrequent to find completely rusted galvanized pipes few years after their installation).