Applicable Standards: GB/T 24596-2021, EN 15189, ISO 24131-1
External polyurethane (PU) coating is widely used for buried water and wastewater ductile iron pipes, providing excellent soil corrosion resistance, impact resistance and wear resistance. The system adopts two-component high-pressure hot spray technology instead of conventional brush painting.
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Process Flow: Pipe inspection → Hydrostatic test → Socket & spigot protection → External blast cleaning → Surface defect repair → Moisture drying → Pipe preheating → PU hot spray coating → Curing → Coating inspection → Local repair → Final acceptance & warehousing