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I want to have a lockable metal cage covering my backflow preventers to guard against theft of the brass and copper. I searched multiple websites but have not been able to find a standard size cage that fits the proposed installation and would like advice regarding having a custom cage fabricated.

I'm planning to install two backflow preventers side by side above ground. The first one (Wilkins 350XL 1 1/2", Double Check Assembly) is on the main water line between the meter and the house. There is a tee immediately after the outlet of the Wilkins 350XL that connects (via a short length of pipe and a 90 degree elbow) to the inlet of the second backflow preventer, a Wilkins 375XL, 1 1/2" Reduced Pressure Assembly. The first device is required by the water company and sized to supply the fire sprinkler system in the house. The second device connects to the irrigation system and was selected because some sprinkler heads are above the level of the Reduced Pressure Assembly on this gradually sloping lot. Both devices must be installed a minimum of 12 inches above grade and will be positioned side by side. The overall width of the installation is 26"; overall length is 27"; height is 23". The configuration is close to being a cube with equal sides. Standard cages are designed for one backflow preventer, smaller in width than length. I don't mind the cage being a bit taller than required, perhaps up to 30", but don't want to have a cage that is far longer than necessary in order to have the required width.

I'm looking for a cage similar to the design of the Gorilla Cage GC-2 shown on the SprinklerWarehouse.com website, but wider and just a bit taller so the curved sides allow clearance between the cage interior and the side-by-side backflow preventers. Does anyone know if the manufacturer of Gorilla Cages accepts custom orders?

I see BackflowProtection.com offers quotes on custom cages that look similar to the Gorilla Cages and intend to obtain a quote from them. Then it will be possible to compare the custom cage price to the price of two standard cages (one for each backflow preventer assembly, but with the connection between them piped below grade, resulting in a slight reduction in flow due to extra fittings). I hope the cost of one custom cage is less than the cost of two standard cages.

Any other sources of lockable metal cages you can recommend that have the approximate 27"x27"x27" size I need, or companies that will fabricate these types of cages?

Thanks in advance for any advice you can provide.

An electronics enclosure could be an alternative if it's constructed similar to a cage, not a completely enclosed cabinet, so that any water coming out of the Reduced Pressure Assembly relief valve could easily drain away.

BTW, I just looked at the GorillaCages.com site and see they do offer custom fabrication service and will ask for a quote.

Thanks for your advice - I'll continue to explore electronics enclosures to see what I can find.

The installation is still in the planning stage, so your suggestion of an in-line installation is very helpful. I suppose I did not focus on an in-line configuration months ago when I began thinking about it because I wanted to minimize how far into the yard the above-ground plumbing would extend into the yard, perpendicular to a wood fence at the property line. However, when I estimate the difference in overall length for an in-line installation, it's only about 15 inches more. Better yet, it's easier and less expensive to find standard cages to fit than having one custom made.

Using 90 deg brass street elbows at each end and a brass tee with two short (just enough pipe to get a wrench on it) nipples in the middle, the minimum overall length is 40 inches, although unions on the vertical risers will increase the overall length slightly.

The GC-3 at 42" long (I.D.) would be a snug fit, but the GC-4 at 48" long would be a comfortable fit and probably spare the power coated finish from scratches while the cage is being put on or lifted off in the future.

Following your suggestion to look at electronics enclosures, I found a number of companies who make cages for HVAC units; suffering from the same type of metal theft as backflow preventers. Some of them do custom-only work.

Thank you very much for your helpful advice! I'm sure I'll return to this forum when I start planning irrigation system details.