n.不透气；气密；密封
The special connections ensure that the system has excellent air tightness. 特别的连接方式保证了系统优良的气密性。
Compressed air testing can be carried out only, if accepted by the classification society. 如果船级社同意，可以只做气密试验。
Seat tightness achieved with torque as opposed to line pressure. 利用扭矩而不是管路压力来实现阀座的密封。
When all air has been removed, the vessel is sealed off. 把全部空气抽走后，将容器密封起来。
