Gas Oven Explosion Relief Requirement

[cadtocam]

We have a heat treat indexing oven, gas direct fired combustion chamber design. If no solvent or any combustible materials inside oven enclosure, does it still need explosion relief design by NFPA code? Let me know. Thanks.
John

 

[danw2]

http://www.industrialheating.com/articles/89343-furnace-safety-q-a-part-1

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July 8, 2010, Furnace Safety Q&A (part 1)

Q: Please explain the new requirement for explosion relief.

A: NFPA 86 has required explosion relief on most ovens and furnaces for 40 years or more. The 2011 Edition
will permit oven manufacturers to compute the required vent area in one of two ways: (a) the traditional guidance
in NFPA 86, which calls for 1 ft2 of vent area per every 15 ft3 of furnace volume, or (b) the computational
methods given in NFPA 68 – Standard on Explosion Prevention by Deflagration Venting (2007).

Q: Are smokehouse ovens, paint-booth ovens, coffee-bean roasters, textile dryers, laminator ovens, etc. exempt from NFPA explosion-relief requirements?

A: Ovens of light construction are not exempt from the requirement for explosion relief in NFPA 86. Furnaces of “heavy-wall” construction (e.g., vacuum furnaces) are listed as exceptions to the explosion-relief requirement because it is usually impractical to install explosion relief in such equipment, and furthermore, the vessel itself is more capable (albeit seldom fully capable) of containing the pressure buildup from a deflagration than light-construction ovens. Exceptions are itemized in NFPA 86 for low-oxygen atmosphere ovens, thermal oxidizers and the work chambers of indirect-fired ovens.