The way you can determine PVC vs ABS plastic is by the solvent used to "weld" them together. Another way is how they soften when heated. PVC will, when heated will get soft but not stringy as opposed to ABS. When cutting ABS it tends to melt back together as the warm blade cuts it no so with PVC. ABS is softer and more plyable then PVC. That's why ABS is used in plastic toys as opposed to PVC which is used in pipe of all kinds. Many years ago pipe was made out of ABS but it was against code to glue. weld, ABS to PVC
as they have different expansion and contraction properties.
ABS pipe was black and PVC is either orange, fire sprinkler pipe, white for fresh water and beige for waste or vent pipe. However: this is not a given rule but a good guideline.
PVC comes in schedule 20 for light weight, drain pipe, 40 for domestic water and waste use and 60 for heavyweight work like piping in around swimming pools.
Black Polypropylene pipe used for irrigation can not be ,welded, but must be clamped. It has a slippery surface with is ideal for minimal friction loss in pressurized liquids. You can heat it to slip onto the barbed fitting to achieve a tighter seal when clamping. This process also allows you to force undersize pipe onto larger barbed, ribbed fittings.
It is true that ABS plastic will soften in the sun and can even warp out of shape. PVC can lay in the sun and won't show signs of softening until around 120F degrees.
You just had lession 101 in plastic Haz-Mat class
Hope this info is helpful.
All Aboard,
tgood
PS I might add that CPVC pipe is for drinking water and can stand a much higher hot water temperature.