Ductile Iron Rubber Disc Check Valve for Municipal Drainage Systems

Ductile Iron Rubber Disc Check Valve Metal Valve For Municipal Drainage

     This is a rubber flap check valve (also called a rubber plate check valve), which belongs to the check valve family and achieves one-way water stopping by "elastic rubber flap". The following is a disassembly from the structure, principle, and application:

Core structure & working logic

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).

Application scenarios & value

Municipal sewage pipe network: There are many impurities in the sewage (sand, debris), and the rubber flap check valve is not afraid of blockage! For example, in the community sewage riser and the urban sewage trunk pipe, the backflow of sewage (such as the downstream pipe is blocked, the sewage backflow) will be blocked by the rubber flap to prevent the sewage from backflowing into the community and the street.

Building drainage pipe: The drainage riser of a high-rise building, the rubber flap check valve can prevent the lower sewage from flowing back to the upper floor (for example, if the drainage of the ground floor shop is blocked, the sewage may flow back from the toilet on the second floor, and it will be blocked if it is installed).

Rainwater drainage system: urban rainwater pipe network, underground garage drainage pump outlet, rainwater pushes the rubber flap to discharge when it rains; after the pump is stopped, the rubber flap is closed to prevent rainwater from flowing back into the garage (more suitable for "dirty water, many impurities" than the swing type).

Compared with the characteristics of other check valves

✔️ Good anti-blocking performance: the rubber flap is soft and elastic, and the hair and mud in the sewage are not easy to get stuck in the valve flap (the swing type metal valve flap + shaft is easily entangled by debris).

✔️ Silent: When the rubber flap is closed, it fits elastically, and there is no metal collision sound (for example, when the drain pipe flows back at night, the swing check valve may "clang" and the rubber flap is quieter).

❌ Not resistant to high temperature: rubber material is afraid of high temperature, generally suitable for ≤80℃ medium (hot water pipeline cannot be used, which will cause rubber aging).

       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!

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