人孔(锅炉, 下水道供人出入检修用的)人孔, 检修孔(a hole, usually with a cover, through which a person may enter a sewer, boiler, drain, or similar structure.)下水道出入孔:一种常带有盖的孔道,人可以由此孔进出排道、锅炉、下水管或类似设施。 人孔是安装在储罐顶上的安全应急通气装置,通常与...
人孔 人孔:(锅炉, 下水道供人出入检修用的)人孔, 检修孔(a hole, usually with a cover, through which a person may enter a sewer, boiler, drain, or similar structure.)下水道出入孔:一种常带有盖的孔道,人可以由此孔进出排道、锅炉、下水管或类似设施。