Evening chaps first time on here and I need a few questions answered before I sit my licence exam in Nov. I have a lot of study material but its old stuff so things might have changed so here goes
1.Is there still such a thing as a one pipe and two pipe system in NZ
2. I read in AS3500 that you are not allow to install any valves on a HWC after the cold water expansion valve, now I have always installed a ball valve directly on the HWC, is this now wrong under AS3500
3.Is dual flush cistern compulsory in NZ
4.Looking again at AS3500 a couple of photos show the HWC valve train different to the way I have piped it out in the pass . I have always gone Isolating valve, filter, non return, limiting , then the CWEV is this now wrong. The photo shows the non return after the limiting.
5.Can you use a 32mm PVC for a waste pipe under AS3500

Thanking you for you help in advance 

Linkback: https://www.plumbers.nz/ask-plumbers-trade/43/few-questions-need-answering/1553/