ASME A112.18.8 pdf download Sanitary Waste Valves for Plumbing Drainage Systems 3.1.2 Performance Requirements. The valve shall demonstrate flow rates not less than (a) 1 1 ∕ 4 in. (31.8 mm): 9.5 gpm (36 L/min), valve alone on wash basin, bidet (b) 1 1 ∕ 2 in. (38.1 mm): 13.5 gpm (51 L/min), valve alone on bath (c) 1 1...