sch20,

sch120 factory steel pipe api 5l psl1 psl2, sch120 140 160 oil
construction materials water piping carbon steel pipe sch20
sch40 6 inch pre-galvanized gi round pipe/hot dip galvanized erw
异径管r(e) dn150x100 sch20 20g 抗hic
smls sch10 steel pipe