SYPHONIC FLOW - Supadiverta - syphonic rainwater diverter

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A revolutionary new way to harvest rainwater



Anti-vortex baffle
Vortex slows flow

The anti-vortex baffle stops a vortex spiralling air down the pipe, allowing the pipe to flow full of water. The effect of gravity on FULL FLOW generates a vacuum that sucks water into the outlet at high velocity, increasing flow rates by up to 1,000%.

Weir flow generates a vortex that spirals air down a pipe. This causes the water to also spiral down the inner wall rather than fall down the pipe. For this reason and unless blocked, downpipes never contain less than 2/3rds air!

Purging the air to achieve syphonic flow

Water above the baffle stops the vortex, trapping a large air pocket in the pipe. The air pocket’s buoyant force is equal to the weight of the water it displaces and it initially resists the head and the downward flow. Inflowing water creates turbulence and calves air bubbles off the air pocket and carries them downwards, reducing the size of the air pocket until it has negative buoyancy and is purged from the pipe. Syphonic full flow is then established.

SUPADIVERTA syphonic flow
- small pipes transferring large quantities of water

Using 20mm PVC pressure pipe, each outlet will flow at approximately 58 litres per minute with a one metre head.
This is equivalent to harvesting a steady 99mm of rain over one hour on a 35sq metre roof area!
NOTE: 1 mm of rain on 1 sq metre = 1 litre

  • Full flow pipe must remain primed.

  • Minimise friction loss over long runs.

  • Self cleaning pipework with SUPADIVERTA.

  • Flow rates over 30 metres.

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NOTE: Supadiverta is engineered to use 20mm PVC class 12 vertical drops and purging happens within seconds.

Using a 25 mm x 20 mm PVC valve socket to fit a 25 mm class 12 PVC pressure pipe to the second priority outlet substantially increases flow rates but bigger air pockets in larger diameter pipes can take longer to purge. If the larger 25mm pipe is slow to prime, the third priority outlet will operate during the purge. For further details, see the FITTING page.

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