Prevent explosion propagation through extraction ducting
Non-return valves are passive safety devices designed to isolate extraction systems in the event of an explosion and help prevent flame, pressure and dust from travelling back toward the production area. They are an important part of explosion protection concepts for dust extraction systems operating in potentially hazardous environments.
What are non-return valves and when should you use them?
Non-return valves are installed in extraction ducting to help prevent an explosion originating in a filter or connected process from propagating back through the suction line toward the production hall. Under normal operation, contaminated air passes through the valve toward the filtration system. If an explosion creates a rapid reverse pressure wave, the valve closes and isolates the upstream duct section. They are commonly used in dust extraction systems where combustible dust may be present and where explosion isolation is required between the filter and the production process. Tehno Filter specifically positions both NRV and SNR for ATEX applications and explosion propagation protection.
Why is explosion isolation important?
A filter explosion does not necessarily remain inside the filter. Without appropriate isolation, pressure, flame and burning particulate can travel through connected ducting and reach occupied production areas or other connected equipment. A correctly selected non-return valve helps create a passive barrier between the hazardous equipment and the production environment.
Non-return valves in our range
Two product families cover different duct diameters and system configurations for industrial explosion isolation.
NRV
SNR
Where non-return valves are used
Non-return valves are used wherever combustible dust and connected extraction ducting create a potential explosion propagation path.
Passive protection built into the extraction system
NEED EXPLOSION ISOLATION?
Tell us the duct size, dust type and extraction system configuration. Our team can help determine the appropriate non-return valve and how it should be integrated into the overall explosion protection concept.

