Sprinkler Polyethylene Piping: what is lifespan?

Sprinkler Polyethylene Piping: This is what I have in my yard sprinkler system:



I am just curious what the lifespan of Polyethylene Piping?
30 years?
40 years?
50 years?

It will pretty much last indefinitely in the ground. I think somewhere along the line I saw something about a 50 year warranty???

Long time. Ive never seen any just "rot". Mechanical damage to it can neccisitate replacement, or debris lodged inside though.