Vacuum filter / Negative-pressure filter

Suction belt filter SAFI-T (fleece filter)

The most compact POLO suction belt filter, SAFI-T series, cleans liquids fully automatically. The main field of application is the purification of highly viscous oils, such as those found in rolling processes and on presses. Due to its compact design, there is room for it on every machine and it is therefore very popular.

Their advantages

  • Vacuum filter in drum design
  • Extremely small space required
  • Degassing of the coolant
  • Simple installation

Short info

  • Dry dirt removal
  • Perfect utilisation of the filter aid
  • Even for small amounts
  • Robust and durable

Compact vacuum filter

Due to its compact design, this filter requires little space and still offers a high liquid flow rate. These filters are extremely robust and durable. They are ideal for use with ” viscous” oils in particular. Fleece intake and dirt discharge are located on the front side, which characterises the compact design additionally. At the same time, this makes it very user-friendly.


The filter housing consists of a high-quality welded steel construction. The special feature of this system is a rotating perforated plate drum located in the filter housing. A transport chain is guided around this drum and deflection shafts to a special, inclined discharge. The filter fleece lies on the transport chain as a filter aid, which rests laterally in a sealing area on both sides of the drum. An exhauster for generating the negative pressure and a discharge pump are mounted and tubed on the filter. Float switches in the dirt and clean chambers control the filter function.


The dirty liquid flows into the dirt chamber of the filter through an inlet distributor that avoids turbulence.

The exhauster draws the liquid through the fleece into the inside of the perforated plate drum, thus creating a negative pressure. This negative pressure increases the flow rate, allows the filter cake to build up higher and, as air is drawn through this filter cake, produces a dry stab-proof discharge. The higher-building filter cake provides a high-quality filter layer that improves the degree of filtration.

The filter discharge pump directs the cleaned liquid into a clean tank. At a maximum level in the dirt chamber, a belt pre-stroke is triggered. At the same time, the used fleece is conveyed into the dirt container and a fresh fleece is drawn in. The filtering process does not have to be interrupted for this operation; no buffer tank is necessary!


Compact design

Lightweight fleece usable

Made in Germany

Process safety

Low maintenance

Picture gallery

Data sheet

Standard sizesSAFI-T0.4SAFI-T0.7SAFI-T1.0SAFI-T1.7
Mounting dimesion L x W700 x 7201000 x 7451000 x 12701150 x 1340
Height 1050155015501550
Weight approx. (kg)260400620700
Inlet R 1 1/2" DN 125DN 150DN 150
OutletR 1 1/2" DN 65DN 100DN 100
OverflowR 3"DN 125DN 150DN 150
Volume approx. (litres) 90250500600
Flow rate max. (l/min) emulsions*20050010001300
Flow rate max. (l/min) oils*100250500650
Connected load (kW)1,74,65,47,2
Supply voltage 3 ~ 400 V 50 Hz3 ~ 400 V 50 Hz3 ~ 400 V 50 Hz3 ~ 400 V 50 Hz

*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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