Water and gas require pipes to supply residential homes and businesses. Gas supplies power to stoves, water heaters, furnaces and other devices. Water is essential and obvious. The two most common types of steel pipe used to carry water and gas are black pipe and galvanized pipe. Confusion is common among home owners, and even some professionals, as to where to use these steel pipes and under what circumstances.

Galvanized Pipe
Galvanized steel pipe is covered with a zinc material to make the steel pipe more resistant to corrosion. The primary use of galvanized pipe is to supply water to homes and buildings. The zinc also prevents the buildup of mineral deposits that can clog the water line.

Black 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 natural gas into homes and businesses. The pipe is manufactured without a seam, making it a stronger and safer pipe to carry gas. The black steel pipe is also used for fire sprinkler systems because it is more fire-resistant than galvanized pipe.

In brief:

• Black pipe and galvanized pipe are made of steel
• Galvanized pipe has a zinc coating, black pipe does not
• Galvanized pipe is ideal for carrying water but not suitable for carrying gas
• Galvanized pipe is more expensive because of zinc coating
• Galvanized pipe is more durable

You do not want to use galvanized pipe for gas because of the galvanized coating. Over time pieces of the galvanized steel will flake off and clog your gas regulators and burner units.

Never mix galvanized and black iron or where they touch corrosion will be accelerated.