NEC 352 give's rules for PVC installation. Also NEC 362 for nonmetallic tubing which is in essence PVC. There doesn't seem to be any provision forbidding the use of PVC conduit in high buildings however, there are rules for spacing the supports.
Erickench, thank you so much for your information and good to hear from you. I will check NEC 352 and NEC 362, then if I have any questions. Can I consult you?
I would like to ask you again about the intallation standard in your country about the non-metallic conduit. What is your country-standard? What is standard number?