A.填料函泄漏 B.閥桿升降失靈 C.填料壓蓋斷裂 D.關(guān)閉件泄漏
A.填料函泄漏 B.填料壓蓋斷裂 C.關(guān)閉件泄漏 D.閥桿升降失靈
A.填料函泄漏 B.關(guān)閉件泄漏 C.閥桿升降失靈 D.填料壓蓋斷裂