manhole

• Damaged footpaths , railings , manholes
  破烂的行人路栏杆沙井
• Manhole unit for marine auxiliary boiler
  船用铺锅炉人孔装置
• " why are manholes covers round ?
  为什么下水道的井盖是圆的？
• Handholds for entrance into accessible manholes - requirements , testing
  人孔入口处的把手.要求和试验
• " why are manhole covers round ?
  为什么下水道的井盖是圆的？
• Keep proper length of pipe when put into the manhole
  布放后应保留适当长度于引进端人(手)孔或拉箱内。
• Why is a manhole cover round
  为什么下水道的盖子是圆形的？
• Standard test methods for concrete pipe , manhole sections , or tile
  混凝土管人孔构件或瓦管的标准试验方法
• Standard practice for sealing sewer manholes using chemical grouting
  用化学灌浆密封污水道检查孔的标准规程
• Specification for manhole cover assembly , raised , oiltight , and watertight
  可提升的防油防水的人孔盖组件规范