Flow Controllers

Flow controllers in taps and showers are essential for maintaining water pressure and conserving water. Also known as flow regulators or restrictors, they play a crucial role in water efficiency.

Sometimes house holders and plumbers remove flow controllers when installing a new tap or shower, mistakenly believing that this will make it work better.

Leaving flow controllers in place is the best practice for optimal tap and shower performance. Modern taps and showers are designed to only function effectively with a flow controller.

The Water Efficiency Labelling and Standards (WELS) scheme regulates flow controllers used in regulated products or sold separately.

How they work

A flow controller consists of an engineered housing, a seating area, and a flexible precision O-ring. The O-ring, in its relaxed state, allows a specific flow rate.

As water pressure increases, the O-ring flattens into the seating area, reducing space for water to pass while keeping a consistent flow rate and pressure. When pressure decreases, the O-ring returns to its original state.


WELS 3D Flow Controller animation transcript (DOCX 208 KB)


  • Allow the correct spray pattern of water through showerheads.
  • Enable showers to function as designed, which reduces the risk of leaks, cracks or failures.
  • Maintain water pressure in homes, even with multiple outlets.
  • Help to regulate the water pressure across multiple dwellings or buildings, ensuring adequate pressure across individual properties.
  • Contribute to warranty conditions; removing them can void the product warranty.
  • Save water by reducing flow rates of more than 20 litres per minute to as little as 2 to 4 litres per minute for taps and 5 to 7 litres per minute for showers.
  • Save energy, reduce carbon emissions, and lower energy bills. The less water used means less water needs to be heated.
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