This:
I have seen this sort of thing used in Brutus systems and elsewhere. Does anyone have a shopping list for building one of the assemblies? Seems like a lot of little parts that you have to order and assemble yourself, but I guess that’s just how McMaster-Carr works (also it’s cheaper)
You might want to look at the loc-line systems.
They have quite a few items that would work for a sparge arm.
I use the 50813 kit in my mash tun. It is great for recirculation and adjusting the water flow to keep it above the grain bed.
http://www.modularhose.com/Loc-Line-12-System/12-kits/50813
Here is a photo of the way one brewer uses it
The 51837 could also be used for a sparge ring
http://www.modularhose.com/Loc-Line-12-System/12-kits/Loc-Line-51837
Very reasonable prices and quick shipping.
I know people use this stuff, with apparent success, but I’d be a little worried about the material. Its made of acetal plastic, the stated max temperature is 170F which you’ll pass during sparging. Acetal is also susceptible to acid hydrolysis (mash is pH 5) and degradation under hot water conditions.
If it works for you, great, but I’ll stick to a length of stainless tubing bent to form.