What is the difference between Galvanized Pipe and Black pipe?

Question: What is the difference between Galvanized Steel Pipe and Black Steel Pipe?

Answer: 

1 Surface Treatment

Galvanized steel pipe is covered with a zinc material to make the steel pipe more resistant to corrosion. The primary use of galvanized steel pipe is to carry water to homes and commercial buildings. The zinc also prevents the buildup of mineral deposits that can clog the water line. Galvanized steel pipe is commonly used as scaffolding frames because of its resistance to corrosion.

Black steel pipe is different from galvanized steel pipe because it is uncoated. The dark color comes from the iron-oxide formed on its surface during manufacturing. The primary purpose of black steel pipe is to carry propane or natural gas into residential homes and commercial buildings. The pipe is manufactured without a seam, making it a better pipe to carry gas. The black steel pipe is also used for fire sprinkler systems because it is more fire-resistant than galvanized steel pipe.

2 Problems

The zinc on galvanized pipe flakes off over time, clogging the pipe. The flaking can cause the pipe to burst. Utilizing galvanized pipe to carry gas can create a hazard. Black steel pipe, on the other hand, corrodes more easily than galvanized pipe and allows minerals from water to build up inside it.

3 Cost

Galvanized steel pipe costs more than black steel pipe because of the zinc coating and manufacturing process involved in producing galvanized pipe. Galvanized fittings also cost more than the fittings used on black steel. Galvanized steel pipe must never be joined with black steel pipe during the construction of a residential home or commercial building.

before galvanizing ( spiral pipe) 

after galvanizing ( spiral pipe)