Typically water transmission pipelines are either constructed using concrete pressure pipes, ductile iron pipes, steel pipes or GRP/GRE pipes. At the lower end of the dimensional range plastic pipes (such as HDPE) may be used.
There are various historical/design reasons as to why individual authorities & consulting engineers may prefer different valve designs. Some designers are more comfortable with gate valves others with butterfly valves – and within each valve category there are also more design options available. Choice of valves can also depend on project specific applications as well as availability for different pressure classes.
Products according to DIN, BS, AWWA and AS.