GF金属蝶阀蝶阀GF金属蝶阀057型金属蝶阀带有棘齿设置的手柄Material: 材料种类Housing: ?aluminium, Rilsana-coated外壳 ?铝,覆有丽绚涂层Disc: ?-ductile iron, Rilsana-coated蝶板 ?锻铁,覆有丽绚涂层-stainless steel ? -aluminium-branze ?不锈钢 ?铝铜合金口径尺寸Dimensio