A.聚四氟乙烯襯里閥 B.不銹鋼閥 C.聚丙烯閥 D.PVC閥
A.4.5%-95% B.4.1%-74.2% C.5%-87.5% D.3.1-93.5%
A.98% B.90% C.80% D.85%