... welded steel pipe ,electric galvanized pipe, pre-galvanized pipe, square and rectangular steel pipe, welded steel pipe, ERW pipe, etc. ... industry, machinery, construction, utilities, shipbuilding, oil field and other national economic fields, growing with more than 5, ... Used for low pressure liquids conveyance, such as water, gas, and construction4) Surface: Galvanized (inside & outside)5) Zinc coating ...