With the way winter sneaks up on us here in Nebraska, I put them on all my systems. It allows you to water into that gray zone of october when a lot of people fertilize and over seed the lawns. It helps make sure your turf is ready to go in the spring. They add about 10 dollars per zone for 2 drains each. Well worth the money if you consider what a frozen line would cost. I also have been adding an auto drain to the main line in my valve manifold. I still blow the system out to remove any puddles, but that doesn't have to take place until late in the season.

Thanks for the feedback. Have you had any trouble with them sticking open? Have you gambled and not blown out the lines? Also, I've read that you shouldn't put them in the main line but I haven't heard why. Sounds like you have and haven't had a problem.

I have had 1 failure of all the drains I have put in, and it was bad from the start, I think it was an incomplete unit from the factory.

My supplier has special threaded drains he recommends for mainlines. I add a 45 elbow and reducer bushing to the valve assembly. You could accomplish the same thing with a bushing and a threaded plug (brass only) but you would have to remove it to drain the main.

You would still want to blow the system as a precaution, in case you have valleys in your pipe, or caught water in the heads etc. You wouldn't have to though.