I currently have this setup:

enter image description here enter image description here

In the diagrams below the green circles are individual valve boxes (why would they have used 3 boxes instead of 1 here?), the black lines are 1" plastic irrigation pipe, and the numbers are zone outputs (Hunter PGV valves).

enter image description here

I would like to add two zones. The space (center to center) between 1 and 2 is 5", and the space between 2 and 3 is 8.5". It seems like it would allllmost fit to add the new zones (7 & 8) like this, changing to one large rectangular box. Unfortunately there are structures to the left and right of this whole setup, so I can't just add an additional box to either side. Is there a minimum recommended distance between valves? Are there such things as "thin valves" for an application like this?

enter image description here

In fact, I actually want to run one of the new zones the other direction:

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Is there a standard way to do this?

  • Topologicially, what you ask is fine. Otherwise, it's in the details (materials, couplings, etc...). Can you take a good photo of the current setup?
    – BowlOfRed
    Oct 13, 2020 at 20:28
  • @BowlOfRed I added some pictures. It might look like there is nothing to the left, but there is a generator there so there is large electrical and gas that I don't want to fool around with. Oct 13, 2020 at 21:05
  • I ended up adding zone 7, replacing the circular box over 1&2 and 3&4 with a rectangular box around 1-2-7-3-4, and forgoing zone 8 for a totally different option. Nov 8, 2020 at 13:04

2 Answers 2


It looks like you have some "wiggle room" - the existing valves could be pushed closer together, though it might require rebuilding the manifold (branches off the supply line).

My 7-zone system is indeed in a single rectangular box. For ease of identification, I would recommend (at least) labeling each zone valve and if at all possible, re-number from 1 to 8 consecutively to avoid future confusion.

For your zone 8 to point the other direction, you should either route it around after it exits the box or dig deeper and route it underneath the valves. The valve should be in-line with the rest of them. Use care not to exceed the maximum bend radius for your tubing and do not kink it.

  • if I cut out the whole manifold and squeeze things together (and add the new ones), then can I use "funny pipe" to get to the existing zone pipes so I don't have to redo everything on that side as well? I haven't been able to find anything about 1) if that's acceptable or 2) what kind of connectors/converters to use (i.e. can I connect funny pipe directly to the valves? How would I connect the funny pipe to the existing poly pipe? etc.) Oct 13, 2020 at 21:22
  • (not an irrigation specialist but) I'd minimize pipe types and number of joints if possible. Unless your picture is a little distorted, it looks like there's some play in the direction of the valves (existing pairs of valves look a little "squeezed" already) so you may have more tolerance, with a bit of digging, than you expect. Funny pipe is typically used at the low-pressure ends of the runs so may not be ideal for near-valve use. If you did use it, I'd also use hose clamps to prevent leaks due to pressure and the correct barb fittings to meet the valve end and poly pipe end. Oct 13, 2020 at 21:37

This answer is based on the assumption that the pressure is not too high for polypipe with clips.

You can add extra valves easily.

By either cutting the pipe and adding a T piece, or by replacing existing T pieces with a Cross (X) piece.

Clear away the dirt around the pipes, and try to wash the joints and pipes.

Older polypipe is more likely to fail at the joints when taken off and on; better to replace each piece that is cut, likewise with the clips. New pipe will also need less strength to push on the joiners.

By adding a T (or X) with a longer section of pipe, you can start a new row of valves.

It will probably be easier to work with the manifold on the bench.

OR.. use parts a bit like in these photos - I hear they are good to 80psi. Usually I see these as T and elbow shapes joined with the double ended bits with the purple rings.

Example I saw yesterday:

enter image description here enter image description here

enter image description here

  • Of course there are off-the-shelf components to make manifolds like these, without having to push reluctant polypipe over barbs. Oct 15, 2020 at 4:44
  • what do you mean? Like pre-assembled manifolds? Nov 8, 2020 at 13:02
  • I havent found a photo, but they come is T's and elbows, and are compression fittings (they have a rubber ring). Easy to take apart and reassemble, and suitable for high pressure. Nov 10, 2020 at 22:12
  • I have edited my answer to include photos - a bit random sorry. Nov 21, 2020 at 12:29
  • Wow, that would have been so much easier. What are they called/who makes them? Nov 21, 2020 at 14:33

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