SPRINKLER TALK FORUM - You Got Questions, We've Got Answers

I find a union isn't necessary, its just one more place for a leak to develop.

I would solder on a 1" copper female adaptor and then install a 1" pvc male adaptor. From there you can run pvc to all your manifolds

Yes, for a transition from copper to PVC, you just need a female copper and a male PVC. Don't make the transition using male copper to female PVC because you risk cracking the PVC when you tighten it down on the copper.

However, I'm currently disagreeing with the use of a union. I can't not conceive of a valve manifold that doesn't provide at least one union going to each valve. I want to have more than one or two valves in a single underground box. But there isn't any way to fit more than two vavles in a typical box (about 16"x12" in size) such that you can replace a single valve without messing with the other valves and bending the pipe.

As for the copper to pvc transition. My first thought was to use the female copper and male pvc, but... My local plumbing expert (he is very knoledgeable about plumbing codes) recommended using a female pvc with a ss reinforcing band. He said the male pvc could also fail under the compression loads of a pipe thread connection. Im not totally sure if I totally buy it, but I do plan of checking into it further. Also, teflon compound over tape since tape may leak if the joint is backed off and a maximum of two full turns after "finger tight" for proper tightening. I would appreciate any feedback about the male/female configuration, thanks...