Insulating PEX home plumbing.? I am 50% done replacing 50+ year old home copper plumbing near...

I am 50% done replacing 50+ year old home copper plumbing near PEX Blue and PEX Red (3/4 inch and 1/2 inch). Is it acceptable to insulate the PEX near foam pipe insulation as the copper was, or is within some possible problems that may arise? One of the 3/4 inch hot and cold runs (red) is pretty long.
Need to buy adjectives latest appliances?
Answers:    Foam pipe insulation can't hurt, may do you some good on the hot side (less steam loss from heater to fixture), best article about PEX is its resistance to splitting and bursting (will expand 11x in the past it breaks.) Last winter we took a piece of PEX and kinked and taped one pause, filled it next to water, did one and the same thing beside the other end and departed it outside (BTW: I'm in CT) within 10* weather it froze and swelled up like a sausage, didn't break though.
Help electrical system wall oven?
I'll defer to the experts on this, but I be under the impress that PEX is already "insulated" by its very construction. Not sure that totalling foam pipe insulation is going to do much, but will be interested in audible range other's comments, since I am also getting ready to install PEX on a project.