Valve Body (Blue Body):

• Material: Ductile iron (surface anti-corrosion spray), pressure-resistant, corrosion-resistant, suitable for water, sewage and other media
• The flanges at both ends connect the pipes for easy splicing (such as municipal sewage pipe networks, building drainage pipes)
• Cast "DN100": nominal diameter 100mm (adapt to the inner diameter of the pipe to ensure the flow of the medium)

Rubber Flap ("Elastic Door" Hidden Inside):

• The soul of the check valve: There are two (or more) rubber flaps in the valve body, like elastic door plates
• When the medium flows forward (along the pipeline arrow), the water flow thrust opens the rubber flap and the pipeline is connected
• When the medium flows back, the rubber flap relies on its own elasticity + reverse water pressure to automatically fit the valve seat, close the pipeline, and prevent backflow

No Additional Moving Parts:

Compared to the "metal valve disc + rotating shaft" of the swing check valve, the rubber flap check valve has a simpler structure - it relies on the elasticity of the rubber to open and close, and is not easy to get stuck (especially in impurity-containing media such as sewage, where impurities are not easy to entangle the rubber flap).

Simply put, this is the "anti-backflow guard of the sewage pipe", which relies on the elasticity of rubber to solve the problem of "dirty water backflow + easy to clog". Especially in municipal and building drainage systems, it is the first choice to replace traditional check valves - not afraid of clogging, quiet, and easy to install!