Check with Specific Mechanical. We have been using one of their machines for close to 10 years. It was designed as a single keg washer but we ended up modifying it to clean 2 at once. We are pushing close to 4k bbls this year and our keg washer has no trouble keeping up, although it is a full day of washing kegs when we do it (usually only one day a week though). It's a nice machine too, all automated. Couple the keg, invert it on the stand, push start and walk away. Keg is cleaned, sanitized, purged and pressurized all to your specifications.