The WaStop check valve installs in stormwater systems, providing immediate protection against flooding and backflow. Its unique, simple, and effective design also prevents unwanted odour and pest intrusion. This model features a flange for bolting onto a head wall, ensuring secure and fast installation. Technical specification Nominal diameter DN 450 (NPS 18) Max. Flow Velocity 3 m/s (9.8 fps) Weight 31 kg (68.3 lb) # Bolt holes (#B) 12 Bolt Circle Diameter (BCD) 580 mm (22.8 in) Dimension 443 mm (17.4 in) Valve body length (L) 840 mm (33.1 in) Outer Ø (OD) 443 mm (17.4 in) Ø Bolt Holes (ØB) 13 mm (0.5 in) Max. Flow Volume 478 l/s (7576.5 GPM) Max. ID Host Pipe 464 mm (18.3 in) Min. ID Host Pipe 446 mm (17.6 in) Flange bolt pattern Wapro Fasteners mtrl. 316L stainless steel Product sheet (PDF) Technical specification (PDF) Dimensional drawing (PDF)