The Ductile Iron Rubber Flap Check Valve (also known as a silent check valve or rubber disc check valve) is the simplest and most economical backflow prevention device. It consists of a cast ductile iron body with an integral seat and a flexible rubber flap that is secured at the top. When forward flow occurs, the rubber flap bends open, allowing media to pass. When flow stops or reverses, the flap immediately falls back against the seat, creating a soft, silent seal. Because there are no springs, metal hinges, or metal-to-metal contact points, this valve is ideal for dirty or abrasive media like sewage, sludge, or raw water containing sand and debris. The valve also produces no slamming noise — a major advantage for building applications.
Why Choose Us / Advantage
Best for Sewage: No hinge pin or spring to get jammed by rags or solids.
Available with Counterweight: For vertical installation or higher backpressure.
WRAS Approved Rubber: EPDM and NBR options meet drinking water standards.
Low Cost: Most economical check valve type for large diameters.
Quick Delivery: DN100-DN600 available ex-stock.
Technical Data
★ Type Rubber Flap / Silent Check
★ Body Ductile Iron QT450 (epoxy coated)
★ Flap EPDM / NBR rubber reinforced with fabric
★ Seat Built-in body seat (machined)
★ Pressure PN10 / PN16
★ Size Range DN50 – DN800
★ Cracking Pressure < 0.005 MPa
★ Connection Wafer or Flanged
Applications
● Sewage pumping stations
● Stormwater drainage outfalls
● Sludge and slurry lines
● Building drainage systems
● Fish hatchery and aquaculture water lines
