A water line, made up of joined sections of PVC pipe, may have any desired length. The pipe is suspended from drops at ten (10) foot intervals for example. The pipe is partially supported in plastic drop hangers having insulating and elastic properties. The drop hangers have an aperture at the upper...http://www.google.fr/patents/US4753196?utm_source=gb-gplus-shareBrevet US4753196 - Animal watering apparatus and method
