How to ...
How to ...
service a disc filter
This editorial describes the filtration process as well as the procedure to service a manual disc filter . The procedures have been based on one of the most extensively used manual filters being the Arkal 2 inch Dual model . Other models of filters and especially alternative brands will use different procedures , however the underlying basic maintenance systems
remain the same for all disc filters . - by Mike de Villiers
Filter systems are classified into three types , namely sand filters , mesh / screen filters and disc filters . The filter type , as well as the grade and capacity of the filter , has to be carefully selected dependent on a number of key factors , such as the type of irrigation emitter , water quality , required flow rate as well as the available water source . These decisions are critical to the performance of the entire irrigation scheme and require the services of a suitably qualified and approved designer .
Filtration is an essential function in any micro irrigation system as it prevents the ingress of solids into the system . Filter systems are classified according to varying levels of filtration . Pre-filtration , Primary filtration and Secondary or block filtration . Primary filtration is the most important function , with pre-filtration and block filtration added as required , dependent on water quality and the type of emitters being used .
INTRODUCTION
The process of filtration is to remove unwanted particles from the water supply , which are retained in the filter body and eventually impede the flow rate through the filter . The increase in the pressure required to maintain optimum flow through the filter is the indicator that the filter needs maintenance . Many systems incorporate automated or manual backwashing / back-flushing functions that reverse the water flow through the filter to remove the unwanted debris , whereas less sophisticated filter systems need to be manually dismantled and cleaned as required . Needless to say , factors such as the pump capacity and pressure need to accommodate the flow rate required to achieve backwashing , in addition to the required needs of the irrigation system .
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SABI | FEBRUARY / MARCH 2017