What Is the Difference in Black Steel Pipe and Galvanized Steel Pipe?

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 pipe is commonly used as scaffolding frames because of its resistance to corrosion.
Black Steel Pipe

Black steel pipe is different from galvanized 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 pipe.

Galvanized Seamless steel pipe 
1)Shape:Round,Square,Rectangular 
2)ASTM A53,BS1387-85 
3)Steel structural,furniturer,fencing,fluid pipe