In terms of flanges/flange plates, although most people are unfamiliar with the concept, it is actually indispensable to everyone in the city. Flanges are widely used for the interconnection of various high and low-pressure pipelines, such as the city's potable water supply pipeline network, drainage pipeline network, winter boiler heating circulation pipelines, and energy pipelines like oil and natural gas, etc. Their role in pipelines is akin to the connecting sections between tracks on the familiar railway.