常压人孔是最普通的人孔，是不带压力的人孔，一般安装在罐顶，是制作工人或者修护工人在建罐、清罐、倒罐时的出入口，而人孔的强度和密封是技术关键，但先对于带压人孔来说，常压人孔强度和密封性要求次之。
atmospheric pressure chamber is the most common manholes, manhole is without pressure, generally installed on the roof, is a production worker or repair workers in cans, tank, exit when tank, and the intensity of the manhole and seal is the key technology, but first for manhole with pressure, normal pressure manhole strength and tightness requirements.