Explosion protection
Process-safe explosion protection for man and machine
Our explosion protection technology
For maximum safety
HET Filter sets the highest standards and new benchmarks in explosion protection.
Our unique technology ensures lasting safety without additional measures and expenses.
Our filter systems are electrically conductive and do not generate their own ignition sources. In addition, our filter systems offer constructive explosion protection due to the specially developed explosion pressure shock resistant design. The explosion pressure is relieved internally via the filter cells, which also serve as an effective flame arrester.
Dusts with a specific pmax of 10 bar can be handled, as the pressure surge is reduced internally to such an extent that the system can withstand it. Due to this internal pressure relief, the filter system does not suffer any permanent damage even in the event of an explosion and the collected dust remains safely in the filter.
Our filter systems are developed and designed in accordance with the ATEX Directive 2014/34/EU, as well as many other standards and directives. We work closely with notified bodies to provide you with the best possible protection for your process.
Directive 2014/34/EU divides equipment group II into the following categories:
G (Gase, Dämpfe, Nebel) | D (Staub) | ||
---|---|---|---|
Kategorie | Betriebsmittel geeignet für | Kategorie | Betriebsmittel geeignet für |
1G | Zone 0 | 1G | Zone 20 |
2G | Zone 1 | 2G | Zone 21 |
3G | Zone 2 | 3G | Zone 22 |

Highest explosion protection
Ex100
The filter system is electrically conductive and does not generate its own ignition sources.
Ex200
Due to its explosion pressure shock resistant design, the filter system offers constructive explosion protection based on the principle of partial filling. The explosion pressure is relieved internally via the filter cells, which also serve as an effective flame arrester.
Dusts with a specific pmax of 10 bar can be handled, as the pressure surge is reduced internally to 1 bar. Due to this internal pressure relief, the system does not suffer any permanent damage even in the event of an explosion.
The offered filter unit is designed according to ATEX Directive 2014/34/EU and approved and certified by FSA Mannheim, notified body 0558.
In the event of an explosion, no permanent deformation occurs according to the explosion test, even with dusts up to a Kst value of 590 bar*m/s.
From a Kst value of 300 bar*m/s, a blocking slide valve for the primary filter cell and a flap monitoring system must be provided for this purpose.
After internal cleaning, filter replacement and functional testing, the filter system can continue to be operated without any further measures.
In the event of an explosion, no permanent deformation occurs according to the explosion test, even with dusts up to a Kst value of 590 bar*m/s.
From a Kst value of 300 bar*m/s, a blocking slide valve for the primary filter cell and a flap monitoring system must be provided for this purpose.
After internal cleaning, filter replacement and functional testing, the filter system can continue to be operated without any further measures.
Special Features:
- In the event of a dust explosion, the filter housing is not damaged
- The special arrangement of the filter cells acts as an effective flame arrester to prevent ignition on the clean gas side
- Explosion pressure and heat are dissipated via the filter cells.
No external pressure relief or explosion suppression measures are required, which is a huge cost advantage.
Things to know about the topic
Explosion protection

Filtration
Ensures clean air
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Containment
safe protection against hazardous substances
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HET Filter systems
Our product variety
Tailored to your area of application, we can supply you with filter systems and filter cells from a single source. The modular design of our filter systems gives you a wide variety of options.