Shallow well pump prob

[Mitcheal]

Hello. I'm having issues with my pump. My setup well to pump of course. Then on the out side I have a galvanized nipple that switches to ofc to a tank and out to the irrigation. The problem is the pump keeps blowing out where the nipple switches to pvc. My pressure cutoff is at 70. Should it be lower? Should I switch to pvc further up the chain?
Thanks, mitch

 

[Valveman]

70 should not be "blowing off" anything. Sounds like a water hammer problem. Post a pic.