Safety Related Properties of Gases

Porous materials for acetylene cylinders

Information on approved porous materials may be downloaded in the following list.

• Porous materials for acetylene cylinders: Information about approvals in Germany
  (PDF); version: August 2010

Acetylene cylinders are filled entirely with a porous material which must be able to stop the propagation of an acetylene decomposition within the cylinder, initiated e.g. by a backfire or an external heating of the acetylene cylinder.

Testing is carried out according to the standards:

• DIN EN 1800 Transportable gas cylinders – Acetylene cylinders – Basic requirements and definitions
• ISO 3807-1 Cylinders for acetylene – Basic requirements – Part 1: Cylinders without fusible plugs

Ignition cavity with cover wagon for the backfire test of acetylene cylinders (enlarged picture)

The required backfire tests of acetylene cylinders are carried out at the BAM Test Site Technical Safety at Horstwalde. After a drop procedure the acetylene cylinder is heated to 35 °C. The acetylene decomposition is initiated through an explosion tube by melting a metal wire. Due to the risk of an explosion, this test is carried out in an ignition cavity protected by a cover wagon.

The standards for type testing of acetylene cylinders are referred to in Annex A of ADR (European Agreement concerning the International Carriage of Dangerous Goods by Road) for the approval of acetylene cylinders and therefore are also applicable for the conformity assessment according to Directive 1999/36/EC (TPED).

As a notified body with the identification no. 0589 BAM carries out all examinations required for the conformity assessment of porous masses for acetylene cylinders. BAM is also named as the competent authority for the approval of porous masses for acetylene cylinders in the "Gefahrgutverordnung Straße und Eisenbahn" (GGVSE, Ordinance on Dangerous Goods for Road and Rail).

Porous materials which are not suitable or damaged are not able to stop an acetylene decomposition, so that the increase in temperature and pressure eventually will cause the cylinder to burst. The above figure shows how an acetylene decomposition spreads through the clearance between porous material and cylinder wall.

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