安全闸 meaning in Chinese

emergency lock
safety brake

The safety gates at the railroad crossing are lowering
铁路交叉路口的安全闸正在放下来。
Transportation and handling of liquefied gases . tanker vehicules filled and emptied from below . internal safety gates dn 80 and dn 100 for operating pressures between 4 bar and 40 bar
液态气体的运输和装卸.底部注入和排出的罐车.工作压力范围为4巴- 40巴用标准尺寸dn 80和dn 100的内部安全闸