Hypertherm Powermax30 AIR, Operator'S Manual

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Hypertherm
1-11
11/08
SAFETY
DRY DUST COLLECTION INFORMATION
At some sites, dry dust can represent a potential explosion hazard.
The U.S. National Fire Protection Association’s 2007 edition of NFPA standard 68, “Explosion Protection by
Deflagration Venting,” provides requirements for the design, location, installation, maintenance, and use of
devices and systems to vent combustion gases and pressures after any deflagration event. Consult with the
manufacturer or installer of any dry dust collection system for applicable requirements before you install a new
dry dust collection system or make significant changes in the process or materials used with an existing dry
dust collection system.
Consult your local “Authority Having Jurisdiction” (AHJ) to determine whether any edition of NFPA 68 has
been “adopted by reference” in your local building codes.
Refer to NFPA68 for definitions and explanations of regulatory terms such as deflagration, AHJ, adopted by
reference, the Kst value, deflagration index, and other terms.
Note 1 – Hypertherm’s interpretation of these new requirements is that unless a site-specific evaluation has
been completed to determine that all dust generated is not combustible, the 2007 edition of NFPA 68
requires the use of explosion vents designed to the worst-case Kst value (see annex F) that could be
generated from dust so that the explosion vent size and type can be designed. NFPA 68 does not specifically
identify plasma cutting or other thermal cutting processes as requiring deflagration venting systems, but it
does apply these new requirements to all dry dust collection systems.
Note 2 – Users of Hypertherm manuals should consult and comply with all applicable federal, state, and local
laws and regulations. Hypertherm does not, by the publication of any Hypertherm manual, intend to urge
action that is not in compliance with all applicable regulations and standards, and this manual may never be
construed as doing so.