26/10/2025
The main types of pipes are Black Iron (BI) pipes, which are uncoated steel, and Galvanized Iron (GI) pipes, which are steel pipes coated with a layer of zinc. GI pipes are further categorized by weight into Class A (Light), Class B (Medium), and Class C (Heavy), which determines their thickness and durability.
Black Iron (BI) Pipes
Description: These are steel pipes with a black, uncoated surface, which is actually a layer of iron oxide from the manufacturing process.
Primary Use: Typically used for applications where corrosion resistance is not the main concern, such as for transporting natural gas, propane, or oil, and for fire sprinkler systems.
Durability: Less durable in corrosive environments compared to GI pipes because they lack a protective coating.
Galvanized Iron (GI) Pipes
Description: Steel pipes that have been coated with a protective layer of zinc to prevent rust and corrosion. They have a silver-white appearance.
Primary Use: Commonly used for water supply lines, plumbing, and in large construction projects where corrosion resistance is necessary.
Types:
Class A (Light): The lightest and cheapest type, suitable for less demanding applications.
Class B (Medium): A heavier gauge than Class A, offering a balance of cost and durability.
Class C (Heavy): The thickest and most durable class, used for high-pressure or heavy-duty applications.
Manufacturing variations: GI pipes can be made through hot-dipped galvanization (immersing the pipe in molten zinc) or electro-galvanization (using electrical means to bond a zinc layer).
