TECHNICAL 35
How to save water
By
Patrick Gordon - consultant
Water saving is foremost on everybody ’ s minds at the moment . The new buzz word is ‘ rainwater harvesting ’. To make use of rainwater and to process grey water is a responsible thing to do and we should all be doing it . By doing your part you will be helping preserve our failing infrastructure .
But that is not all that you can do . By lightening the demand on the water supply system , we will not need to supplement the water supply as much . Some of us may not be able to do rainwater harvesting due to residential restrictions ,
So how can you do your part ? Did you know that older taps and mixers can use as much as 60l of water per minute . As an example , if your shower is fitted with two Undertile taps and you use a rain type shower , your water consumption can easily be 50- 60l / min . The plumbing industry has access to retrofittable flow restrictors that can be fitted to most taps and mixers .
Images supplied by Patrick Gordon
However , these are first generation water saving devices . The better option is to use a PCA type flow restrictor . So , what is the difference ? A normal flow restrictor is just a small hole in a disk that restricts the water flow . The higher the pressure the more water it allows through . A PCA restrictor has an elastometer that changes shape when more water pressure is applied to it . The more it deflects , the more it closes the flow path . By doing this the maximum flow is controlled to be no more than the designed flow rate .
In the lefthand picture the Elastometer can be seen in the relaxed position , allowing maximum flow . The righthand picture shows the Elastometer under pressure . The ring has been squeezed into all the apertures , and is now restricting the flow . The more pressure is applied to the Elastometer the more the flow path will be restricted . The result is that when the designed flowrate through the PCA restrictor is achieved no extra flow will be allowed .
This type of restrictor is available for all aerated taps , shower roses and hand showers .
" By lightening the demand on the water supply system , we will not need to supplement the water supply as much ."
Even with this as a bit of a DIY project you can do your bit to save water . PA
April 2025 Volume 31 I Number 02 www . plumbingafrica . co . za