90° Tank Overflow Bends - Rain Harvesting

90° Tank Overflow Bends

Tank Overflows
Purpose built true 90° bends designed for rainwater tank overflows. Fit the bend directly into your overflow to allow your overflow pipes to be installed with a tight fit parallel to your tank wall.
Size 90mm TATO10
Size 100mm TATO19
  • 90mm
  • 100mm
Water Level

Easy to Install

These male and female tank overflows can be easily installed into a wide range of overflows and mosquito proof screens. They are also UV stablised and AS4020 compliant.


90deg Bend Vs 88 Deg V4

Purpose built rainwater
harvesting bends

The 90° bend allows you to drop your overflow pipe straight down and flush to your rainwater tank – for 100mm overflows, no “kick” with the standard 88° bend (standard 100mm bends are not available in 90°). Overflow pipework will look aesthetically pleasing.

Tank Overflows provide additional security for your tank’s connections, and allow you to effectively manage overflowing water. Tank Overflows also allow you to increase your water tank’s storage, enabling you more ability to plan for volume.

Learn more about the 4 pillars of designing a Rain Harvesting system. 

  • Specifications

  • Installation

    Using the bend to direct water away from your overflow

    Simply use PVC solvent glue to glue the bend directly to your overflow in the direction required. Depending on whether your overflow has a male (spigot) or female (socket) fitting, you may require an adaptor. Then glue in pipework onto the fitting as required.


    Using the bend as a high level overflow

    Note that we also have a range of overflows with flanges which are better suited to be used as an overflow if you prefer to use this style.

    1. Mark the centerpoint of where the overflow will sit.
    2. Use a holesaw with the same diameter as the bend to drill a hole in the tank. Remove any swarf or flashing from the hole.
    3. Insert the bend through the hole, facing the bend upwards.
    4. Silicon around the bend as required to secure it in place. Then glue in pipework onto the fitting as required.
  • Maintenance

    When properly installed, your tank overflow should be maintenance-free.

  • What's in the box?
    • 90° Tank Overflow Bend
  • Tools you might need
    • Holesaw

    • Marker pen

    • Silicon

    • PVC Solvent Glue and primer

  • Product FAQs

    My tank is overflowing at the inlet rather than the outlet. What should I do?

    1. Check that your tank screen is free from debris, ie. leaves, sediment
    2. Your tank outlet may be restricted by a blocked Mozzie Stoppa or another obstruction.
    3. Check your overflow outlet for the presence of an obstruction and remove.
    4. Alternately, the level of your tank overflow may sit above the base of your tank inlet.
    5. Check that the outlet pipe is equal to or greater than the combind capacity of the pipe feeding your tank inlet
    6. If a Mozzie Stoppa is installed, remove, inspect and clean if necessary before reinstalling it at the outlet or replacing with a Mozzie Stoppa Easy-Clean.

    If your inlet/overflow issue persists, remove your tank screen and check for floating debris on the water surface. Floating debris such as shavings from the tank installation process’ may be blocking the Mozzie Stoppa during overflow and drifting away from the overflow when overflow has stopped.

    Should I choose a regular tank overflow or a high level product?

    High or extra high tank overflows offer a simple and effective way to increase your tank’s storage capacity.

    Whichever tank overflow product you choose to use, your overflow needs to sit below the base of your tank inlet screen. The advantage of the high level overflow is that it raises the maximum water level within the tank.

    What size should I choose?

    The diameter of the overflow must be equal to or larger than the diameter of the inlet pipe.

    Do I need silicon to seal my overflow to the tank?

    You can choose to use a gasket or silicon to seal your overflow to your tank. Silicon is not required if you use a gasket. All our tank overflow kits come with a gasket.

    Do I need a gasket to seal my overflow to the tank?

    You can choose to use a gasket or silicon to seal your overflow to your tank. A gasket is not required if you use silicon. All our tank overflow kits come with a gasket.

    Which way should I orient my high level overflow?

    The bend on your high level tank overflow should face up towards the top of your tank in order to increase your tank’s storage volume and overflow height.

    Can I install my high level overflow sideways?

    Yes. We recommend installing your high level overflow with the bend facing directly upwards, however, it can also be installed on an angle to adjust the upper level. This may be necessary to ensure the overflow level stays below the base of your tank inlet and/or tank inlet screen.

    How do I connect two tanks?

    When connecting two tanks, it’s best to connect them at the base with a balance line. It is important to ensure that the tank receiving water from the roof or other catchment area has an overflow outlet.

    Should I mosquito-proof my tank overflow outlet?

    Yes, it is important to mosquito-proof your tank outlet to keep mosquitoes and other pests out of your rainwater system. You can do this using a mosquito-proof tank outlet screen such as a Mozzie Stoppa Easy-Clean. All our tank overflow kits come with a mosquito-proof Mozzie Stoppa screen.

Products you may be interested in

Easy Clean Tank Overflow Kit High
Easy Clean Tank Overflow Kit High
90mm (with Easy-Clean)
Mozzie Stoppa Easy-Clean
Mozzie Stoppa Easy-Clean
Flap Valve Plain
Flap Valve Plain

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