scope:

This standard sets the performance requirements for explosion venting systems. These systems are typically used on the exterior walls of enclosures (e.g., cut-off rooms, buildings and pre-fabricated stand alone storage buildings) that have been identified as having the potential for a room/building explosion hazard. They shall be examined for their ability to remain in place under normal conditions but to fail at pre-determined pressure levels characteristically associated with explosions.

This standard is intended to be applicable to wall fasteners used to secure wall panels to buildings, latches normally found on ovens and adjustable magnetic release devices used on other types of pressure relieving systems.

This standard is intended to evaluate only those hazards investigated and is not intended to determine suitability for the end use of the product.

This standard does not apply to detonations, bulk auto-ignition of gases or unconfined deflagrations such as open air or vapor cloud explosions or flameless duct explosion venting devices.

This standard does not provide any guidelines on the placement of venting panels or determining the amount of venting area needed for a given occupancy or construction. For recommendations on this type of information, refer to the latest edition of FM Global Property Loss Prevention Data Sheet 1-44, Damage Limiting Construction.

Purpose

This standard states Approval requirements for explosion venting systems including fasteners and latches for damage limiting construction.

Accidental explosions in confined areas generally result in over-pressure situations where the actual pressures far exceed the design strength of the enclosure. This condition will result in significant damage to the enclosure which may be a room in a larger building or a separate stand alone building. To mitigate the potential damage caused by accidental explosions, some form of damage limiting construction (DLC) is needed. Explosion venting panels are used as an element of damage limiting construction .A common DLC design would combine venting panels with reinforced walls.

One style of damage limiting construction works by designing certain parts of the structure (generally the roof or walls) as pressure resistant and other areas (generally external walls as pressure relieving. This pressure relieving area results in a weak point (usually a wall panel or panels) on the exterior of the enclosure that will fail at a pressure below the design strength of the pressure resistant elements of the enclosure. The net effect of this design is the products of the explosion (i.e., excess pressure and flame) are directed out of the protected enclosure to a predefined location through the vent panel while the remainder of the enclosure remains intact.

One of the most common methods of securing the pressure reliving panels to an enclosure is with explosion venting fasteners. Under normal conditions, the explosion venting fasteners secure the wall panels to the structure and are able to withstand typical loadings such as wind. These fasteners allow the panels to remain in place but are designed to fail when a specific force per fastener is exceeded such as would be the case during an explosion.

In addition to large enclosures like buildings or rooms having a need for explosion venting due to potential explosion hazards, there are many pieces of equipment (e.g., industrial ovens) that have the potential for an internal explosion as well. There is also a need to limit damage to this equipment by providing damage limiting construction. Commonly access doors can be used for explosion venting by providing latches specifically designed to release the door during an explosion. These fasteners/latches may have different operating methods but they perform the same essential function - to secure a panel or door in place under normal conditions and release at a predetermined load that will allow venting of the enclosure.

Approval criteria shall include, but are not limited to, performance requirements, marking requirements, an examination of manufacturing facility(ies), an audit of quality assurance procedures, and a follow-up program.