手动圆形通风蝶阀手动矩形通风蝶阀电动圆形通风蝶阀电动矩形通风蝶阀气动圆形通风蝶阀气动矩形通风蝶阀

• Hand circle ventilating butterfly valve Hand rectangle ventilating butterfly valve Electric circle ventilatingbutterfly valve Electric rectangle ventiating butterfly valve Pneumatic circle ventilating butterfly valve Pneumatic rectangle ventilating butterfly valve