Illinois Society of Architects · Chicago · leaf 525
B-Fig. 1.Wade Accessible flushing backwatervalve for prevention of floodedcellars. … B-Fig. 6_.Automatic and hand shut-off back-water valve combination.
Architecture · Building · Architects
Internet Archive · University of Illinois Urbana-Champaign · Public Domain Mark 1.0. Free to use for anything.
