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