I recently repaired a sprinkler valve that had the threaded adapter to the supply side burst at the bottom of its threads. I had cut a segment of PVC beneath the sprinkler valve and made a coupler and short segment of PVC to go into a new threaded adapter to repair the sprinkler line. My irrigation shutoff valve was closed the whole time as I did the repairs. However when I returned later to check on things I found the pipe and the sprinkler valve were full of water from a slow dribble coming in from somewhere. I had turned off the water and pumped out the standing water so the line was clear when I made the repair but on returning, and with the bonnet/jar-top of the sprinkler valve removed I was able to see the water inside it all. There is no higher elevation where water could be back flow coming down from so I'm guessing the irrigation valve has a small leak at its seal.
The PVC cement had set when I reassembled the sprinkler line and left it alone. I want to know if the water in the pipe will interfere with the PVC cement's curing? The water is not under pressure as I have not opened the irrigation line valve and the bonnet up top is removed. I have not yet returned the line to service as I'm still in the 24 hour curing timeline.