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Graf Carat Septic Tank

A low weight septic tank to be used together with a drainage field. Available in four sizes.


Graf 400mm Extension Piece

SKU: G50076-83 Categories: ,


A septic tank is a ‘mechanical’ way of cleaning your sewage waste so that solids are captured and only liquid is discharged

These Graf Carat septic tanks are divided into two by a partition wall known as a baffle. This baffle helps keep back the suspended solids in the primary chamber where they are trapped and can then break down into sludge over time. The effluent (liquid) flows into the secondary chamber and can then be discharged into a suitable drainage field.

These tanks are available in the following sizes:

2,700l (max. 4 people)

3,750l (max. 11 people)

4,800l (max. 18 people)

6,500l (max. 30 people)

Key benefits:

  • The tank has a ribbed base and is extremely stable
  • Can be installed easily using a gravel backfill which means much easier and cheaper installation costs
  • Low weight: can also be installed in difficult local conditions without a crane
  • Low maintenance: maintenance or cleaning work can be performed through the shafts
  • Tanks can be used as rainwater harvesting systems after thorough cleaning

This kit price includes as standard:

  • An injection moulded plastic Carat tank
  • A mini tank dome
  • A mini telescopic dome shaft suitable for pedestrian loading*
  • Buffer

*Optional variation:  vehicle loading up to 3.5t, maxi tank dome, cast iron cover and a telescopic dome shaft


10 years warranty on the tank

Options available:

Heavy Duty cover – vehicle loading up to 3.5t with a maxi tank dome (DN100 connection), cast iron telescopic dome shaft

Neck Extension – working height 305mm (total height 400mm)

Offloading is the responsibility of the customer

Take a look under the Product Downloads tab above for documents to download

People (Max.) Volume (litres) Length (mm) Width (mm) Height total (mm) Weight (kg)
Standard Cover 4 2,700 2,080 1,565 1,830-2,030 140
Heavy Duty Cover 4 2,700 2,080 1,565 2,150-2,450 180
Standard Cover 11 3,750 2,280 1,755 2,020-2,220 175
Heavy Duty Cover 11 3,750 2,280 1,755 2,340-2,640 215
Standard Cover 18 4,800 2,280 1,985 2,250-2,450 220
Heavy Duty Cover 18 4,800 2,280 1,985 2,570-2,870 260
Standard Cover 30 6,500 2,390 2,190 2,530-2,730 265
Heavy Duty Cover 30 6,500 2,390 2,190 2,850-3,150 305
Downloadable files