The WaStop Inline check valve installs in stormwater systems and outlets, providing immediate protection against flooding and backflow. Its unique, simple, and effective design also prevents unwanted odour, especially at outlets in tidal environments. The standard variant is supplied with an EPDM gasket and mounting tabs. Technical specification Nominal diameter DN 500 (NPS 20) Max. Flow Velocity 4 m/s (13.1 fps) Weight 32 kg (70.5 lb) # Bolt holes (#B) 4 Bolt Circle Diameter (BCD) 636 mm (25 in) Dimension 490 mm (19.3 in) Valve body length (L) 900 mm (35.4 in) Outer Ø (OD) 490 mm (19.3 in) OD incl. gasket (ODG) 518 mm (20.4 in) Ø Bolt Holes (ØB) 10.5 mm (0.4 in) Max. Flow Volume 786 l/s (12458.4 GPM) Max. ID Host Pipe 515 mm (20.3 in) Min. ID Host Pipe 493 mm (19.4 in) Fasteners mtrl. 316L stainless steel Gasket EPDM Product sheet (PDF) Technical specification (PDF) Dimensional drawing (PDF)