Automatic self-cleaning filters, backwashable strainers from BOLL

Automatic filters have a self-cleaning mechanism that periodically flushes out accumulated debris to prevent clogging. Backwashable strainers from BOLLFILTER allow continuous operation and are suitable for systems where manual cleaning is inconvenient. They can be used as connected filters.

Looking for an automatic backwash filter that fits your specific needs?
We have a wide range of automatic filters to choose from, depending on your flow rate, grade of filtration, and type of fluid.

aquaBoll®: Self-cleaning water filter, backwashable strainer with adaptive filter elements »

Flange Connection: DN 50 to DN 500 / 2" to 20"
Filter element: Fine sieve cylinder element, Filter candle element, Sieve cylinder element
Grade of filtration: 10 µm - 5 mm

engineBoll: Automatic filter for lube oil and fuel oil filtration »

Flange Connection: DN 50 to DN 300
Filter element: Muliti-Segment
Grade of filtration: 1µm - 50µm

aquaBoll BWT: Automatic filter for ballast water »

Flange Connection: DN 80 - DN 600 / 3" - 24"
Note: Automatic self-cleaning pre-filtration of sea-water, for the protection of ballast water treatment systems
Filter element: special plated basket with mesh made of super duplex

BOLLFILTER Automatic Type 6.03 AOT: The 2-in-1 solution for water filtration, backwashable and with UV disinfection »

Flange Connection: DN 40 / 1 ½"
Filter element: Slotted and mesh candles
Grade of filtration: Nominal filtration grade: 50 - 100 µm

BOLLFILTER Automatic Type 6.04: Automatic backflushing filter, self-cleaning strainer for water and coolant »

Flange Connection: FNPT DN 40 / 1 ½"
Filter element: Screw-in candles (stainless steel)
Grade of filtration: 10 µm – 500 µm

BOLLFILTER Automatic Type 6.18: Welded backwashing filter, self-cleaning strainer for water »

Flange Connection: DN 500 - DN 1000 / 20" - 40"
Filter element: wedge wire, longitudinal wedge wire candle or wire-mesh candle with smooth surface
Grade of filtration: 10 µm - 5 mm (depending on the size of the filter)

BOLLFILTER Automatic Type 6.21/6.22: Backflushing filter for fuel oil »

Flange Connection: DN 50 (optional with Adapter to DN 32 / 1 1/4") / 2"
Filter element: Multi-Segment
Grade of filtration: optional 10 µm, 25 µm, 34 µm or 48 µm

BOLLFILTER Automatic Type 6.48: Efficient continuous backflushing filter for lube oil »

Flange Connection: DN 40 - DN 300 / 1 1/2" - 12"
Filter element: wire-mesh candles
Grade of filtration: 10 µm to 48 µm

BOLLFILTER Automatic Type 6.64: Self-cleaning filter for the maritime industry »

Flange Connection: DIN Only DN 100 - DN 400 (Approx. 4" - 16")
Filter element: wire-mesh and star pleated candles (made of stainless steel with smooth surface)
Grade of filtration: 6 µm - 50 µm

BOLLFILTER Automatic Type 6.64: backflushing filter for coolants »

Flange Connection: DN 100 to DN 400 / 4" to 18"
Filter element: wire-mesh candles (optional made of stainless steel with smooth surface)
Grade of filtration: 6 µm - 150 µm

BOLLFILTER Automatic Type 6.72: Standard fuel oil automatic self-cleaning filter »

Flange Connection: DN 40 - DN 80 / 1 ½" - 3"
Filter element: wire-mesh and star pleated candles (made of stainless steel with smooth surface)
Grade of filtration: 6 µm - 200 µm

BOLLFILTER Automatic Type 8.64/8.72: Fine filtration for low pressure systems »

Flange Connection: DN 65 - DN 150 / 2 ½" - 6"
Filter element: screw-in candles with star-pleated stainless-steel wire mesh
Grade of filtration: 6 µm absolute, 10 µm absolute

Functionality of the self-cleaning filters

Filtration stage

The medium flows through the filter element either from inside to outside or from outside to inside. Here the dirt particles are retained and the cleaned medium reaches the filter outlet. When the differential pressure reaches a certain value, a signal is transmitted from the differential pressure indicator to the control unit, which automatically triggers the backwashing process.

Backflushing phase

During backflushing, the dirt particles are flushed off of the filtration surface by filtered fluid reversal of flow (own medium or through external flush medium, compressed air or service water).