Cleaning method for pressure-free sewerage, by locking off back pressure of water from sewerage operating opposite the flow of sewage

摘要

A sewage-collecting pit (1B) set to be cleaned is placed in a sewage pipe (2) ahead of another pit (1A). The back pressure of water from the sewerage operating opposite the flow of sewage is then locked off via pipe sealing cushion (3C) at the pit (1C) placed ahead of the pit to be cleaned. A pipe is fitted into the pit to be cleaned which is locked off through a pipe sealing cushion (3B) at the front end.