A.先開(kāi)旁路管閥門,后開(kāi)流量計(jì)下游閥門,再開(kāi)流量計(jì)上游閥門,最后逐步關(guān)閉旁路閥門
B.先開(kāi)旁路管閥門,后開(kāi)流量計(jì)上游閥門,再開(kāi)流量計(jì)下游閥門,最后逐步關(guān)閉旁路閥門
C.先開(kāi)流量計(jì)上游閥門,后開(kāi)旁路管閥門,再開(kāi)流量計(jì)下游閥門,最后逐步關(guān)閉旁路閥門
D.先開(kāi)流量計(jì)下游閥門,后開(kāi)流量計(jì)上游閥門,再開(kāi)旁路管閥門,最后逐步關(guān)閉旁路閥門