Steel pipes are the backbone of large-diameter water transmission infrastructure. Different manufacturing processes, dimensions, and standards result in different types of steel pipes, each suited to specific applications, pressure classes, and project scales.
ERW pipes are manufactured by rolling flat steel strip and welding the seam using high-frequency electric resistance welding. They are available in diameters from 1/2 inch (IS 1239) up to 20 inches (IS 3589). ERW pipes are the most common type used for distribution mains and medium-pressure transmission lines.
HSAW (also called Spiral SAW or SSAW) pipes are manufactured by spirally forming hot-rolled steel coil and welding the seam using submerged arc welding. Available from 200mm to 2000mm diameter, they are the standard for large bulk water transmission mains.
LSAW pipes are made from steel plate formed into a cylinder and welded longitudinally. They have very high dimensional precision and are used for high-pressure, large-diameter applications where HSAW is not suitable.