New explosion isolation flap valves from IEP Technologies, part of the Hoerbiger Group, are a reliable and cost effective way to mitigate the risk of dust explosions propagating to upstream equipment.
IEP Technologies has recently announced the introduction of the IFV and IFV-M Isolation Flap Valves. These self-actuating devices are cost effective, easy to install, and reliable, states the firm. Used in a wide range of industries where dust hazards may exist such as food, wood processing, power generation, chemical, pharmaceutical and plastic; the flap valves are designed to provide explosion protection between process vessels such as dust collectors and cyclones.
According to the company, explosion isolation valves are typically required where two or more process vessels are linked by ductwork and an explosion hazard exists. An isolation flap valve installed in the duct is closed rapidly by the pressure wave from the downstream explosion ahead of the flame front arrival. By stopping the flame from reaching the upstream vessel, it prevents the flame and explosion pressure from reaching the attached vessels and creating a secondary, and often more energetic explosion.
The IFV flap valve is compliant to the Atex Directive and certified by a third party as a dust explosion protection system. The IFV-M model adds integrated monitoring of the flap position and dust accumulation in the valve body, meeting the requirements of the Osha Combustible Dust Directive, NFPA 654, and NFPA 69, adds the firm.
Both models feature a durable carbon steel body and a stainless steel flap. In normal operation, process airflow holds the lightweight flap open with minimal pressure drop. The cylindrical housing design minimizes the risk of product buildup, while the blade axle is mounted entirely within the housing to ensure leak-tightness. A hinged inspection cover provides easy access, supported by a gas spring for valve diameters of DN630 and above.
The isolation flap valves are available in sizes from DN100 to DN710 for dust class ST1 (KST ≤200 bar m/s) for reduced explosion pressures (Pred) up to 1 bar. For ST2 dusts (KST ≤300 bar m/s) they are available in sizes up to DN200.