(Vertical runs of PEX tubing should be supported at every floor and at the mid-floor level, or approximately, every 4-6ft. PEX tubing expands and contracts as water temperature in the system changes. That is why it is recommended to allow 1/8" slack per foot of installed tubing (or approx. 1.5" per every 10ft).)
In a slab rough in, we are always desiring to use electrical PVC sweep 90s.
Unfortunately, UPC states that for sleeving, only materials that are suitable for potable water may be used for sleeving.
Completely stupid rule, because how is there any cross molecular contamination from shoving PEX into a grey Schedule 80 electrical PVC pipe.
So, to be technically conforming, you can make your own cheap, standard PVC
Sch 40 sweep 90s if you have the physical warewithall to heat and bend standard PVC