Vacuum filter / Negative-pressure filter

Suction belt filter SAFI-C (endless belt)

In endless belt design, the filters of the SAFI-C series can be subjected to very large flow rates. As a stand-alone filter, up to max. 8000 litres per minute can be achieved. This high-performance system is the essential core element of central systems. Due to a modular design, the high-performance system can be expanded to achieve even higher flow rates.

Their advantages

  • Suitable for the large flow volumes
  • Compressed dirt cake, dry, landfillable
  • Low maintenance
  • High filter fineness can be achieved

Short info

  • For large central systems
  • Endless belt design
  • May also be operated with fleece as an option
  • High operational safety

Robust, durable and highly efficient

Robustness and durability are the outstanding features of this filter. Especially for central systems, its qualities such as reliability are enormously important. The filter has a special drying unit due to the exhauster, thus very dry filter cakes can be produced. Very fine filtration levels can be achieved by using different endless belts.
By using frequency-controlled components, the energy requirement is matched perfectly to the system output.


The container is welded from sheet steel. A transport chain carries the endless belt or fibre fleece. A drip tray is located under the return. An exhauster generates the negative pressure in the vacuum chamber and a pump discharges the cleaned coolant. The control of the functions, triggered by float switches, is ensured by a control box. The control box is placed externally or on the filter.


The medium is fed to the filter by the inlet distributor, flows through the filter medium and reaches the vacuum chamber cleaned. The filter discharge pump sucks the medium out of the vacuum chamber and conveys it into the clean tank.

The exhauster creates a negative pressure in the vacuum chamber. This negative pressure supports the flow rate considerably and results in a better utilisation of the filter medium due to a higher dirt cake build-up. The built-up filter cake provides an additional, high-quality filter layer and thus improves the degree of filtration.

The pressure gradient between the clean and dirty side, caused by the exhauster, is dimensioned in such a way that the finest particles are washed up but not pulled through. The dirt particles are deposited on the filter aid and reduce the flow more and more.

The level rises on the dirt side of the filter. At a preset level, there is a belt stroke (approx. 50 mm long). The filter cake emerging from the liquid is exposed to the suction effect of the exhauster and is well dried out, additionally supported by the exhaust air of the exhauster.

The dirt is brushed off and dropped into the dirt box. The endless belt is subsequently rinsed clean with purified medium.

The filter process is not interrupted during continued cycling, an additional buffer tank is not necessary!

The built-up filter cake is a valuable filter aid and significantly improves the degree of purity. Due to the short stroke steps, this “precoat medium” is almost completely preserved and the degree of purity remains unchanged.


Made in Germany

Variety of materials

Process safety

Low maintenance

Picture gallery

Data sheet

Standard sizesSAFI-C3.6 ESAFI-C4.1 ESAFI-C5.1 ESAFI-C6.1 ESAFI-C7.1 ESAFI-C8.1 ESAFI-C8.6 ESAFI-C9.1 ESAFI-C10.1 E
Mounting dimesion L x W3340 x 16453710 x 16454450 x 16455190 x 16455930 x 16456670 x 16457040 x 16457410 x 16458150 x 1645
Height 250025002500250025002500250025002500
Weight approx. (kg) 350037004050445048005200540056006000
Volume approx. (litres) 2730329044105300665077708330889010010
Flow rate max. (l/min) emulsions*265030003800455053506100650068507650

*Definition of flow rate: Emulsions and aqueous media approx. 1 mm²/sec at 20 °C and oils up to 15 mm²/sec at 20 °C.
The maximum flow rate of the filter is indicated; depending on the machining process and the degree of contamination, the flow rate may be lower.

Subject to technical changes in the interest of progress.

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