This invention relates to structural changing of the waste water drain trap in housing construction and the double valve water tank of the waste water filter and sanitary ware urinal.
本发明涉及改变住宅建设排水管结构及废水过滤器和卫生洁具便池双阀水箱，改变各楼层废水排水管结构利用二次水自流过滤流入便池水箱冲洗便池及冲洗拖布。
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