Function and selection of valves in water supply network

Water supply pipe network will send water plant water transmission and distribution to millions of households, and therefore distributed in every corner of the city water supply network, pipe length from a few hundreds of kilometers of water supply networks, up to thousands of kilometers.
Water can not be replaced and the survival of people have sex, determines the importance of safe operation of the water supply network. But because of the subjective and objective aspects of the reasons, some failure on the pipeline, pipe network is constantly upgrading water users often need to increase local water supply pipe is difficult to avoid. In order to narrow the scope of water, proper installation of control valves in the pipe network is very necessary. In a city water supply network, therefore, valve number tens of thousands, and located below the city streets without rules.