Nominal flow testing for taps and showers

Low Pressure

• Testing is done at 35kPa dynamic pressure*.
• This means the supply pressure is adjusted until 35kPa is attained. For a free flowing product like a bib tap, the supply pressure might be increased to achieve 35kPa just before the tap.
• If the tap is turned off, the static pressure will most likely be higher than 35kPa.
• Faucets & mixers are tested with both supplies open.
• Multi-function showers are rated at the highest flowing function.

High pressure

• Testing is done at 150, 250 and 350kPa dynamic pressure* (as above) and these results are averaged to provide the flow rating. The only difference here is that all flow rates must not vary from the average flow by more than ±1 l/min. If the variance is more than ±1 l/min, the product fails and is awarded a zero star.
• Faucets, mixers, multi-function showers - see above.

* Dynamic flow pressure is the stabilised pressure before the product testing while water is flowing.

Other tests performed: