This part of ISO 9635 specifies construction and performance requirements and test methods for check
valves, intended for operation in irrigation systems with water at temperatures not exceeding 60 °C, which can
contain fertilizers and other chemicals of the types and concentrations used in agriculture.
It is applicable to hydraulically operated check irrigation valves of DN 15 (1/2 inch) diameter or greater,
designed to operate in the fully open and fully closed positions, but which can also operate for extended time
periods in any intermediate position.
ISO 9635-3:2006 Referenced Document
ISO 9635-1:2006 Agricultural irrigation equipment - Irrigation valves - Part 1: General requirements
ISO 9644:1993 Agricultural irrigation equipment; pressure losses in irrigation valves; test method