My answers after ... below:
-To design an above ground PVC, ambient temperature pipeline can I assume that all segments could have fixed supports?
Yes you could, though I'm not sure what you mean by "segments". Bits of the pipe?
...I mean the segments between supports. My client said all supports would be fixed so that´s what I quoted, many engineers in my company are experts in structural design
-so as I would not need special software
What sort of software to undertake which part of design?
...the design of the supports is not an issue for us but would be if there are sliding or other types of supports. I´ve seen other colleagues use PipePlus for example that handles all types of supports
-but only design the segments as structures.
I'm not following you - design of the pipe or design of the supports?
...only the mechanical pipeline design
-And for water what standards should I use for the structural design?.
What does the contents of the pipe have to do with structural supports / design? If you mean design of the pipe you could probably try some of the AWWA specifications / design documents, but depends on where you are and what you're trying to design.
...I will check AWWA, thanks. It´s water froma a water treatment facility
And yes I know that PVC degrades with the sun, the client said it would be so. This is something we have to check further
Thank you all