Flammgrenser

Flammgrenser, in English commonly referred to as flame arresters, are passive safety devices installed in openings that carry flammable gases, vapors, or vapour-air mixtures. Their primary function is to prevent the propagation of a flame through pipes, ducts, vents, or vessels, thereby reducing the risk of flame or explosion spreading to other parts of a facility.

Construction and operating principle. Flame arresters consist of a housing filled with a matrix of narrow passages, such as wire mesh, expanded metal, or ceramic elements. When a flame front attempts to pass through, the channel geometry cools the flame and disrupts the combustion process, slowing or stopping flame propagation. The devices may rely on cooling, quenching, and flow disturbance to achieve arresting effectiveness. They are designed for specific gas mixtures and operating temperatures, and their performance is rated for particular conditions.

Applications. They are widely used in chemical plants, oil and gas facilities, refineries, storage tanks, and ventilation systems where flammable vapors could travel through openings. Typical installation points include vent lines, drains, crankcase ventilation, and intake or exhaust ducts connected to potentially hazardous equipment.

Standards and maintenance. Flame arresters are manufactured to regional safety standards and may carry certifications such as ATEX or IECEx in Europe, and corresponding national standards elsewhere. Regular inspection and cleaning are recommended to prevent blockage from dust, corrosion, or condensate. They should be sized and installed by qualified personnel to ensure compatibility with the gas-air mixture and system design.

Limitations. Their effectiveness depends on the specific gas mixture, flow rate, and temperature. They are not a substitute for explosion-proof equipment where required, and improper use can reduce protection.