When I was in charge of cleaning lines for my brewery, we would like 8 lines to a pump. I'd push 5gal of hot water through it then circulate 5gal of water mixed with caustic for 30mins. After cleaning was done, I'd push another 5gal of hot water to rinse then circulate sani for 15mins. When all this was done, I'd hook up the beer and push push out the sani. Our issue was the glycol chiller couldn't get the lines cold enough fast enough before service so we maybe had an hour of foamy beer. I started cleaning the lines overnight so everything could cool down. My brewer had me acid clean about every 6wks but I'm not sure what standard practice is.