The BC4 (1″ Blanking Cap) is manufactured from tough, impact resistant and durable polyethylene. The blanking cap can be inserted into the extra valve hole in the DBL4 to prevent water from getting in between the two skins of plastic, increasing the drinkers durability, or can be placed in the DOF1 of the Equine feeders to prevent feed getting lodged inside and blocking the drain off. The blanking cap can be removed and replaced quickly and with ease for easy cleaning and disinfection.