This International Standard specifies construction and performance requirements and test methods for hydraulically operated valves, intended for operation in irrigation systems, with water at tempera-tures not exceeding 50 °C, which may contain fertilizers and chemicals of the types and concen-trations used in agriculture
It applies to hydraulically operated irrigation valves of 15 mm (1/2") diameter or greater which are designed for fully open and fully closed positions However, they may also operate for prolonged use in any intermediate position