Originally Posted by Mike Leary
They are great if you want service work: you not only add water into a drained main/lateral, putting stress on everything, and, since they're installed at a low point, crap can plug the drain, rendering it stuck open or closed.
Proper design is to set them 45 degrees up from straight down. But even the Kings seem to fail, and roots seem to grow into them. I used one once to solve a problem. Lady had the system installed and the only way and I mean the only way was to tie in in the garage where the water line came up through the slab and then out the wall and along it probably 50' to the backyard. You guessed it driveway meter box and side of house all concrete. Well I did the repair because she didnt have "them" winterize it and the main line busted. Master valve and a drain valve to drain the main into a bucket outside. But other than that occasional fix, their pretty worthless.