Today in 1899, US Patent 628084 A was issued, an invention of John D. Freese, for his “Beer Dispensing and Pipe Cleaning Apparatus.” There’s no Abstract, although in the description it includes this summary:

The main object of my invention is to provide convenient means for cleaning the pipes in a beer dispensing system so arranged that an operator may clean the pipes by turning on the water at the dispensing end, the water passing into the beer-pipe near the storage end and thence discharging through the beer faucet.