Chinese to English Other Environment & Ecology 环保领域

This can be seen on the Pump Pressure Gauge and on 1-off each Manifold Pressure Gauges.
这可以在泵压力计以及1分离式的各歧管压力计上看见。
1-off是什么意思？
The Gland Housing has 2-off Single Acting Rod Seals and 2-off Bearings which are located inside the Gland Housing and Act upon the Rod.
密封压盖壳有2个关闭式的单作用活塞杆密封件以及2个关闭式轴承，它们分别位于密封压盖壳内并作用于活塞杆。
2-off是什么意思？分离式吗还是关闭式？