Flat, stable and almost invisible

Posted by Callum Vallance-Poole, on July 26, 2019.

Graf Platin flat tank, ideal for self-construction

Flat plastic rainwater tanks have been created for self-construction due to the low weight, the low installation depth and the low excavation volume. The tank can be installed without the use of an excavator in an already constructed garden. The experts of Graf, the European market leader in rainwater harvesting, recommend it for the weight and height of the tank, as well as its high load bearing capacity, well thought-out filter technology and optimally matched accessory components. There are also clear differences in the manufacturing guarantee: Brands like Graf grant a guarantee of 25 years for this durable rain storage system.

A tank with 1,500 L storage volume like the Graf Flat Platin rainwater harvesting tank can be installed with outer dimensions of 210 x 125 x 70 cm and a weight of 80 kg by two people, without the use of construction machines, in one day. Because of the low height, the tank can be inserted in a different way than a cylindrical tank, without a slope angle. This reduces the excavation volume by as much as 80 percent, saving time and effort during excavation.

Since flat tanks can be retrofitted under existing landscaped or green areas, it is important that the cover is stable and can easily be adapted to the top edge of ground. The Graf telescopic dome shafts are thus continuously height-adjustable and inclinable by 5 degrees. In the colour ‘Lawn Green’ and finishing flush with the ground surface, the tank cover blends harmoniously into the garden, is suitable for pedestrian loading, and does not present an obstacle to mowing. The plastic cover is additionally equipped with a childproofing device. Optionally, the hose for garden irrigation is connected directly to a water hose connection box in the tank cover using a commercially available hose coupling. In addition, a second external water hose connection box with two connections can be positioned freely in the garden. An automatically switching pump in the tank then supplies, for example, the quadrangle connected there with the free rainwater.

The cast iron telescopic dome shaft can be installed flush in a paved or asphalt courtyard and can be safely driven over by vehicles of up to 3.5 t. Due to its high weight, the robust cast cover can not be opened by children.

To avoid the entry of leaves and twigs, a high quality filter is recommended. Graf offers the integrated and self-cleaning Minimax-Pro filter solution. Despite the slight height offset between the inlet and outlet (DN 100) of just 80 mm, the patented filter can handle the water volume of 350 m2 of roof area.

Maximum water yield requires optimum filter function. The Minimax-Pro filters the water with a self-cleaning and thus low-maintenance stainless steel filter insert. The housing is fitted with a transparent cover for ease of filter inspections. The filter insertion’s operations can therefore be inspected without the need to extract the filter insert. With an optional XL removal handle, the filter insert can be easily removed for cleaning even at larger installation depths almost at the height of the top edge of ground. The tank shaft opening with a 60 cm diameter also facilitates access to filter technology.

The Platin flat tank is available in the sizes 1,500 L, 3,000 L, 5,000 L and 7,500 L. The tank is supplied ready for connection with four connections (DN 100) with prefitted lip seals for simple self-assembly.

Graf, the European market leader in rainwater harvesting, also offers well thought-out complete packages for garden and household use of rainwater. Besides the tank, these include the tank cover and the filter system, as well as accessory components and a suitable pump. Rain water can be used not only for garden irrigation, but also for washing clothes and flushing toilets. Thus, up to 50 percent drinking water can be saved.

Callum Vallance-Poole

Marketing Coordinator - Based at our UK HQ in Banbury, Oxfordshire, Callum is responsible for promoting Water Management Systems, Attenuation Tanks, Treatment Plants, Rainwater Harvesting Systems and more!