The issue of waterproofing in water meter manholes has long been a daunting problem for users. In 2004, the state explicitly banned brick-lined manholes and promoted the use of plastic inspection manholes. Drainage inspection manholes thus embarked on a truly commercial journey. However, due to the complexity of the piping and the requirement for waterproofing, no truly mature products have emerged. Several domestic manufacturers of drainage inspection manholes have launched a few water meter manhole products, but due to insufficient market understanding and inability to effectively solve the waterproofing issue, these products have ultimately failed.Since 2009, we have focused on the research and development of plastic inspection manholes, having experienced the die-casting assembly style from 2009-2012, the injection molding assembly style from 2013-2015, and the rotational molding one-piece water metering manholes from 2016-2019. Starting in 2020, we have determined the pressure ...