Steel pipes (1) Seamless steel pipe: material 20#, 45#, 16Mn; Specification Φ57mm-Φ630mm. (2) High-frequency welded pipe: material Q235A/B; Specification Φ15mm-Φ159mm. (3) Galvanized pipe: material Q235A/B; Specification Φ15mm-Φ80mm. (4) Stainless steel pipe: material 304, 316, 321, 430; Specification Φ15mm-Φ159mm. (5) Cast iron pipe: material is spherulitic graphite cast iron, 18#, 22# pig iron.