hermetic package
... hermetic seal 密封 hermetic package 气密外壳 heptode converter 五栅管混频器五栅管变频器 ...
gas tight casing
... gas tight 不漏气的 gas tight casing 气密外壳 gas washer 气体洗涤器 ...
airtight envelope
... airtight cover 密封盖; 气密盖 airtight door 气密门 airtight envelope 气密外壳 ...