Poly pipe has been used for 40 years. We use it to hang up to 2.0 hp pumps at 500' in rock bore wells. He is afraid to use it because he thinks the pump will fall off, or the pipe and pump will fall off the pitless. So he should use long insert males and 3 SS hose clamps each on the pitless and pump insert fittings. He should buy the torque wrench for the hose clamps so he doesn't overtighten them due to his fear and not over heat the pipe to get it on the insert fittings.
You could call another pump guy or driller that is experienced with PE pipe.... here on the east coast (mid west too), you'd have serious trouble finding anyone using galvanized. If not PE pipe, then sch 80 PVC with threaded couplers. Galvanized anything in potable water should be outlawed, it's the worst choice possible.