https://www.barthel-armaturen.de/en/products/valves-and-fittings-for-shipbuilding-and-industry/swing-check-valves/storm-valves/
Storm Valves for Industry & Shipbuilding | Barthel Armaturen
storm valvesfor industryshipbuildingarmaturen
https://perlwitz.de/en/product-katalog/storm-valves-angle-type-din-hna-cast-steel/
Storm valves, angle type, DIN HNA, cast steel - Perlwitz Armaturen
08 - 16 089135 Sturmklappen, Eckform DIN-HNA, Stahlguss
storm valvescast steelangletypedin
https://www.stormwater.com/home/article/33054043/proco-products-inc-beachside-city-prepares-for-future-storm-events-with-check-valves
Beachside City Prepares for Future Storm Events With Check Valves | Stormwater Solutions
In 2012, Long Branch, N.J., was one of many coastal communities that experienced severe flooding during Hurricane Sandy. As water levels rose in Long Branch...
https://www.irrigationexpress.co.nz/product/storm-water-and-dwv-sewer-pipe-slide-valves/
Irrigation Express - Storm Water and DWV (sewer) Pipe Slide Valves Stainless Steel Paddle
Explore watertight PVC push/pull valves with lock handles for seamless Storm Water and DWV pipe connections. Not for pressure. Easy glue, socket joints.