A.1-2 B.3-4 C.10-15 D.20-30
A.3%-4% B.2%-3% C.5%-15% D.0.5%-1.5%
A.萬(wàn)能防噴器 B.液動(dòng)平板閥 C.閘板防噴器 D.節(jié)流閥