单项选择题
A.闸板与密封圈贴紧 B.闸板与密封圈压紧 C.注入密封脂 D.管道内介质挤压活动阀座
A.20g/m3 B.0.01g/m3 C.0.02g/m3 D.0.7g/m3
A.0.5Mpa B.1Mpa C.2Mpa D.3Mpa