Skip to product information

GRAF Carat S Belowground Tanks

The Carat S is a unique plastic tank line that is manufactured to consistent, tight tolerances resulting in a product that is of the highest quality, strength, reliability and versatility. Unlike other below ground plastic tank lines, the Carat tank wall thickness is equal all around and is made from Duralen®, a high-quality food grade polypropylene material that is extremely rigid and impact resistant, therefore ideally suited for producing underground tanks. Carat S Tanks carry a 15 year manufacturers warranty against defect and Duralen® can be easily recycled which reduces waste and its impact on the environment. The Carat S tank line can be outfitted with packaged rainwater and wastewater systems, easily installed before or after delivery to site. It is not suited for potable water.

What Makes This Tank Special:
  • Suitable for H5 vehicle loading up to 3.5 metric tons or approx. 8000 lbs. per axle.
  • Suitable for burial depths up to 1.53 meters or approx. 5 feet ideal for colder climates.
  • Suitable for areas with occasional high water table up to mid tank level when tank is empty.
  • Lowest shipping and handling cost of any tank line
  • Multiple fitting locations and internal baffle configurations allowing for easy linking of tanks for higher volume and for customized applications.
  • Multi-adjustable manway assembly with unique telescoping top shaft that allows for vertical height adjustment of approx. 12 inches (0.3 m), and comes with high quality reliable seals. The telescoping shaft is topped off with a durable pp. lid (cast iron for vehicle loading) and outer flange that adjusts to up to a 5 degree slope and sits flush with the finished grade.
  • Highly accurate and consistent components provide ease of fit every time.
  • Highly competitive with and advantageous over concrete vessels.
  • The Carat Tank Dome or manway shaft base section is 24 high and the telescoping dome shaft section can add 12 more height adjustability. Add the extension section to provide for a further 18 - for a max. 54 burial depth
The Carat S is a unique plastic tank line that is manufactured to consistent, tight tolerances resulting in a product that is of the highest quality, strength, reliability and versatility....
Read More

The Carat S is a unique plastic tank line that is manufactured to consistent, tight tolerances resulting in a product that is of the highest quality, strength, reliability and versatility. Unlike other below ground plastic tank lines, the Carat tank wall thickness is equal all around and is made from Duralen®, a high-quality food grade polypropylene material that is extremely rigid and impact resistant, therefore ideally suited for producing underground tanks. Carat S Tanks carry a 15 year manufacturers warranty against defect and Duralen® can be easily recycled which reduces waste and its impact on the environment. The Carat S tank line can be outfitted with packaged rainwater and wastewater systems, easily installed before or after delivery to site. It is not suited for potable water.

What Makes This Tank Special:
  • Suitable for H5 vehicle loading up to 3.5 metric tons or approx. 8000 lbs. per axle.
  • Suitable for burial depths up to 1.53 meters or approx. 5 feet ideal for colder climates.
  • Suitable for areas with occasional high water table up to mid tank level when tank is empty.
  • Lowest shipping and handling cost of any tank line
  • Multiple fitting locations and internal baffle configurations allowing for easy linking of tanks for higher volume and for customized applications.
  • Multi-adjustable manway assembly with unique telescoping top shaft that allows for vertical height adjustment of approx. 12 inches (0.3 m), and comes with high quality reliable seals. The telescoping shaft is topped off with a durable pp. lid (cast iron for vehicle loading) and outer flange that adjusts to up to a 5 degree slope and sits flush with the finished grade.
  • Highly accurate and consistent components provide ease of fit every time.
  • Highly competitive with and advantageous over concrete vessels.
  • The Carat Tank Dome or manway shaft base section is 24 high and the telescoping dome shaft section can add 12 more height adjustability. Add the extension section to provide for a further 18 - for a max. 54 burial depth