Don't know if anything like that exists. Put in a main valve so that water loss is limited to the system run time. Finding leaks isn't usually all that difficult there's the water, there's the leak (give or take a few feet). I've been repairing systems for seven years now and just last month have my first case of here's the water, where's the leak?
Keep the rocks out of the backfill and don't trench too close to any trees (the roots will play havoc in the long run), use a good glue (Turftite) and primer.
