ISO 9912-4:2018

This document specifies construction requirements and test methods for pressurized granulated media filters, hereinafter referred to as media filters, intended for operation in agricultural irrigation systems.
It is applicable to both manual cleaning media filters and automatic self-cleaning media filters, used as single unit or in batteries (two or more units working in parallel).
This document covers the operation and performance of a media filter, together with all related valves, back flushing mechanism, underdrains, manifolds and other related accessories necessary for the operation of the filter.
This document is applicable to three configurations of a filter.
a) An empty filter vessel (tank) housing.
b) A filter vessel filled with media filter material(s), complete with valves, connections, air release and/or other accessories. This configuration, when connected to and controlled by a flushing control device, is a complete operating single filter unit, usually positioned as a part of a filtration station.
c) A filtration station, called 'filter battery'.
Annex A provides information on types of irrigation media filters.
Annex B provides information on granulated media.