Flexible Flow Interceptor is suitable for use between -30 ℃ ~ 50 ℃ ambient temperatures and in 0 ~ 40 ℃ raw water, rainwater or sewage environment. The interceptor is one of the main devices that make up the Intelligent Flexible Flow Interceptor system. The interceptor is complemented by supporting devices such as sealing components, gas station (can be shared), installation accessories, level meters, SCADA system, control cabinets, rain gauges, and cameras. Flexible Flow Interceptor System, through pneumatic control, is able to achieve the separation of clean water and sewage. The facility can intercept sewage from the neighborhood to the municipal sewer into the wastewater treatment plant for treatment or into a detention tank for storage, and cleaner stormwater from the neighborhood is then discharged to the municipal storm sewer or to a nearby natural water body.