Sweet’s indexed catalogue of building construction for the year 1906 (1906)
New York : Chicago : Architectural Record · leaf 538
4. THE PERFECT SELF-SCOURINGANTI-SYPHON BASIN TRAPSectional View The Perfect Testing Trap prevents theflooding of cellars while testing the drain-age system of buildings. Fig. 6 shows valveclosed, ready for testing. By unscrewingthe hand hole plug about one inch, thewater in the drainage system…
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