Decomposition Blocker FN12 / FN40

Decomposition arrestor, stops dangerous decomposition of acetylene in low-pressure pipelines

  • highest quality from the world market leader
  • safety elements: flame arrestor,  temperature-sensitive cut-off valve
  • stops the explosive decomposition of acetylene via pressure-controlled quick-acting piston valve
  • every device is tested before delivery
  • BAM certified
  • 70 X 160/200 mm, 3.091-3.846 g
  • FN12 Q= approx. 76 m³/h (free flow-off)
  • FN40 Q= approx. 140 m³/h (free flow-off)

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WITT Decomposition Blockers for reliable protection against decomposition of acetylene and flashbacks of fuel gases. Every Arrestor 100% tested.

The best Safety Devices in the world

  • a large surface area flame arrestor of stainless steel construction:
    - stops dangerous decomposition of acetylene independent from flow direction
    - extinguishes any dangerous flashback entering the device in any direction
  • a temperature-sensitive cut-off valve extinguishes sustained flashbacks long before the internal temperature of the arrestor reaches a dangerous level

Operation / Usage:

  • as a Decomposition Blocker for acetylene in medium-pressure pipelines for protection of cylinder equipment and bundles in accordance with DIN EN ISO 14114
  • as a Decomposition Blocker to protect pipelines in supply systems
  • FN40 for double flow capacity
  • WITT Decomposition Blockers may be mounted in any position / orientation
  • the maximum ambient / working temperature is 60 °C / 140 °F


  • it is recommended that an annual body leakage test is performed
  • decomposition Blockers are only to be serviced by the manufacturer


Constructed and tested according to DIN EN ISO 14114
Company certified to ISO 9001 and PED 2014/68/EC Module H
CE-marked in accordance with 2014/68/EC


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