Today in 1889, US Patent 409056 A was issued, an invention of Everett D. Moore, for his “Water Coil Boiler.” There’s no Abstract, although in the description it includes these claims:

The object of my invention is to provide an effective and convenient means for steaming, flushing, and thoroughly cleansing the pipes that are frequently employed for conducting stood that I do not confine myself to a burner beer, wines, and other liquids from a keg, of any particular form of construction. barrel, or other source from a keg, barrel, or other source to the tap or faucet of a beverage-drawing apparatus, which pipes are liable to become fouled and internally coated with sediment from the liquors or beverages passed through them, especially when standing therein over night. The impurities that are thus deposited in the pipes of a beverage-drawing apparatus are liable to taint a series of perforations 12 for the exit of gas. the liquor and are often injurious to health.

Heretofore the pipes of a beverage-drawing apparatus have been cleansed to some extent by forcing through them solutions of potash, lime, and other substances, which, however, are liable themselves to form injurious compounds in the pipes. My invention obviates these difficulties by providing a means for thoroughly cleansing the pipes with steam and hot water, as hereinafter described.