Attached are some notes from a 4 keg semi-auto keg washer I built. It took about 3 months and cost about $2500. I built it as cheap as possible for an automatic washer so feel free to substitute stainless steel, pneumatic valves, or a high temp brewery pump if you have the cash. Hopefully this will get you started but its not a all encompassing list with a step by step parts list or instructions. Sorry, I don’t have the time for putting a compete design tutorial together or to answer how to questions. I’d recommend buying the $15K keg washers from folks like Premier Stainless if you have the money. Its a TON of work and effort to plan out, order, assemble, and test. If you’re not comfortable working with electricity/ wiring or don’t like reading through equipment manuals repeatedly, I wouldn’t try it. Programming is easy once you figure out the logic. I have included the programming and the printout if you decide to use the same controller and configuration. If you’re a brave soul with more heart than money, be safe and good luck!