ASSOCIATIONS
Inferior thermostatic mixing valves increase chance of scalding
9
By
David Poggiolini for IOPSA
There has been a concerning increase in the use of inferior thermostatic mixing valves in solar-heating systems .
These products are also being installed in the hot water systems and on specific plumbing fixtures in old-age homes , clinics , hospitals , and schools .
Quality thermostatic mixing valves protect people from scalding . They achieve this by ensuring a safe water temperature in the bath , shower , basin , bidet , and kitchen sink . This is by accurately blending hot and cold water to keep temperature consistent even when the incoming water pressure or flow fluctuates .
Water from solar-water heating systems can reach temperatures that significantly exceed 65 ° C when they over-perform . The ideal temperature of water at the point varies depending on the application but should never exceed 50 ° C . In baths , basins and showers , the standard water temperature of hot water is at least 38 ° C . To melt fats in the kitchen sink , hot water must be at least 45 ° C .
Brendan Reynolds , Executive Director of the Institute of Plumbing South Africa ( IOPSA ), says that the use of these inferior thermostatic mixing valves places many lives at risk , especially the most vulnerable .
“ Hot water from a solar water heater can reach temperatures of up to 90 ° C . A serious burn can occur within three seconds of being exposed to water that is 60 ° C in temperature . Hot water at 48 ° C can lead to a serious burn within 10 minutes . Many incapacitated people and children who cannot reach the tap quick enough or do not know how or are unable to close it have been burnt very severely by water of these temperatures . Bear in mind that children and the elderly also have thinner skin that burns quickly ,” Reynolds says .
A quality thermostatic valve is manufactured to comply with the SABS 198:2012 standard . The standard enables plumbers and consumers to ascertain that the thermostatic mixing valve will perform as expected .
Reputable South African manufacturers and suppliers of this technology are very familiar with the standard . They also have an intricate understanding of the unique local conditions in which their products operate .
Many of the inferior thermostatic mixing valves that are being used in South Africa are being mass manufactured for an international market by companies in the East . These manufacturers are , therefore , not always aware of the strict standards that govern plumbing installations in the various markets that they supply .
Advanced Valves
Quality thermostatic mixing valves protect people from scalding by ensuring a safe water temperature in the bath , shower , basin , bidet , and kitchen sink .
A thermostatic valve that has been manufactured according to the SABS standard will allow the correct quantity of water through the hot water system . Importantly , it also reacts swiftly in the event of a coldwater supply failure . When this occurs , it automatically shuts down and allows only a small amount of water through the pipe .
The influx of inferior mixing valves in the country over the years has been on the back of a significant increase in demand for solar-water heating systems . These systems reduce water and energy bills , while also mitigating exposure to an extremely strained electricity system . Certainly , a growing awareness of the importance of sustainable living is also driving the uptake of the technology among large property developers and owners , as well as middleand upper-income homeowners .
There has also been an alarming increase in the use of inferior thermostatic mixing valves in solar heating systems for large
November 2022 Volume 28 I Number 9 www . plumbingafrica . co . za