Reduced Pressure Zone Valves (RPZ)
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What is Backflow?
Water fittings regulations require every plumbing system to incorporate protection against backflow. This is often referred to as point of use backflow protection. It can be provided by an air or tap gap arrangement or a mechanical backflow prevention device.
Backflow prevention devices, are required to be manufactured of gunmetal or other dezincification resistant materials.
Wherever practicable plumbing systems should be protected against backflow without the necessity to rely on mechanical backflow protection devices.
Fluid Categories
Regulations classify the health risk posed by potential contaminants using a scale called fluid categories.
There are five fluid categories in total the lowest being 1 no risk the highest 5 a serious health hazard.
Fluid Category |
Description |
Example |
|
1 |
Wholesome (drinking) water supplied by the undertaker |
water direct from a water undertaker’s main |
|
2 |
Wholesome (drinking) water which has been changed either heated or altered in taste, odour or appearance |
Hot water |
|
3 |
Fluids posing a slight health hazard |
low toxicity chemicals such as common disinfectants |
|
4 |
Fluids posing a significant health hazard. |
Toxic substances such as pesticides and environmental organisms |
|
5 |
Fluids posing a serious health hazard |
Pathogenic organisms, radioactive or very toxic substances such as faecal matter |
Further guidance can be found on the WaterRegsUK website.
