Question
James,

We live in Omaha, NE.  I noticed that my sprinkler value control box was filling up with water.  It is a 6 zone system with a PBV above and 6 ft away.  Upon clearing the water and excess clay from around the values I noticed that the 3 values on the right side of the tree had half dollar size filters/reliefs drains etc on the output of the value when the water was turned on they leaked a bit, when the water was stopped they appeared to drain what was in the system.  They leaked/drained when any of the zones were operated.  I cannot find anything about these drain vaules and I thought the systems were closed loop and would drain via the sprinkler heads?  Could the zones be tied together by check-values to drain at the lowest point?

We have decided to put a rock bed to allow for easier drainage.  Thoughts?

Thanks,

Ron

Answer
Ron, Not sure, but I think what you've got there are something called auto drains. They have a little spring loaded valve inside them and what they do is drain the pipes after the sytem runs. I am guessing that that is the way the system is winterized. I don't really care for them and I don't like them. As far as the water draining out of the heads it depends on elevation and what kind of pipe the heads are connected to. PVC(white pipe) will freeze and break very easily. Poly (black pipe) will expand if a little water is left in them and it freezes. Jim