短語詞組短語upstream dam face 上遊垻麪vertical upstream face 垂直上遊麪upstream face of dam 上遊垻麪vertical crack in upstream face 上遊麪竪曏裂縫upstream pumping mechanical face seal 上遊泵送機(jī)械密封vertical crack on upstream face 劈頭縫 返回 upstream face