Modern AWWA C200 steel pipe can have a cement mortar lining per AWWA C205, an epoxy lining per AWWA C210, or a polyurethane lining per AWWA C222. I have seen all specified for combined cycle buried cooling water systems; aboveground risers are not typically cement mortar lined. Reference AWWA...
My company receives RFPs, reviews engineering specifications, and supplies large-diameter cooling water piping for combined cycle plants. I have not seen HDPE specified for any of the combined cycle plants that we are aware of. The thermal expansion/contraction issue is likely a concern and the...
Another choice to consider for a metallic pipe product with corrosion-resistant properties would be ductile iron, available in 4"-64" diameters and flanged/grooved joints. In addition to its high carbon content and protective mill scale layer, all fabricated ductile iron pipe is made with a...