Air
Gaps

• Prevent stormwater backflow from entering your tank and contaminating your rainwater,
  which could happen to you, without you knowing about it.
• Mosquito-proof your tank and stormwater pipes
• Keep frogs, rats and other pests out of your tank and stormwater pipes
• Create a visual inspection point for detecting any overflow issues
• Easily maintain thanks to removable upper and lower screens
• Protect stored rainwater quality
• Easy to Paint
• Easy to Install

How does backflow occur, and how does an air gap help?

In an extreme rainfall event there is the possiblity that water can back up through the stormwater overflow pipe and towards the rainwater tank.

If your local stormwater infrastructure (beyond your property boundary) becomes blocked, the system can “charge”, causing dirty stormwater to surge back through your stormwater pipework. If your rainwater tank overflow is connected to stormwater, this “charged” stormwater can backup into the tank.

If the pipes connected to the overflow of the rainwater tank are crushed, excess water from any pipework connected to the same system could flow back towards the tank, taking with them whatever debris is in the system.

If your tank is going to a soakage pit, in an extreme rain event the pit could become saturated and water can flow back up towards the

An air gap prevents this problem by creating a physical gap between your rainwater tank and stormwater lines. With an air gap, overflowing stormwater is prevented from backing up into your tank. Instead, it will spill out through the front of your air gap.

My screens keep falling out. What should I do?

Check that the bayonet fitting is engaged correctly. Push and turn the top filter to secure the screen in place.

Should I install my air gap at the top or bottom of the overflow?

You can install your air gap at the top or bottom of the vertical overflow pipe. Installing your air gap closer to the top of the overflow will generally make it easier to maintain.

We recommend ensuring you don’t have a charged line which could effect the height of installation.

Can I plumb 100mm pipe into a 90mm air gap?

You can connect the downstream (bottom) side of your air gap to a 100mm pipe with the use of a 100×90 socket reducer. Please consult a licenced plumber for suitability in reducing the upstream (top) connection to your air gap.

The overflowing water from my tank is spilling out the front of my air gap. How can I fix this problem?

Overflowing rainwater from your tank can begin leaking from the air gap if the bottom screen becomes dirty or obstructed. To prevent this problem, regularly check and clean your bottom screen.