I may be the only person who's had this issue, but I ran into a sprinkler pipe problem where the PVC pipe underground popped off a sprinkler head. Now, it didn't 'break', it was the inner threading of the underground pipe... it wore down and became impossible to insert a new gray PVC fitting to attach the Sprinkler Head.

I didn't have a tap large enough to try and re-thread the inside of the pipe, and I am lazy so I didn't want to dig everything up and cut the pipe for a new one which would've been the 'proper' way, so I decided to rig it and find a coupler at Home Depot that would go OVER the underground pvc pipe (using pvc glue), allowing me to slide in one end of the smaller gray pvs pipe, which would then allow me to screw on the sprinkler head.

Well, apparently a coupler like that doesn't even exist! Not in my local DIY stores, anyway. So I made one and it has been working absolutely amazing. I made the part out of PETG for durability and the PVC Glue cured to both pipes (and my PETG coupler) perfectly!

I don't know if anyone will ever find the need for this, but it is a SUPER easy fix for yard sprinkler systems with VERY minimal dig-up in your yard.

Cheers!