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Is it true that NFPA 86C has changed?

Mark Lanham
Applications Engineer

Yes, it's true. In fact, NFPA 86C no longer exists. The requirements for "Industrial Furnaces Using a Special Processing Atmosphere," formally defined in the 1999 version of NFPA 86C, have been incorporated into NFPA 86 as of July 18, 2003. Now, NFPA 86 combines the furnace safety requirements for all types of industrial furnaces, including Class A – Food and Baking Ovens, Class B – Melting Furnaces, Class C – Furnaces Using Special Processing Atmospheres, and Class D – Vacuum Furnaces.

The previous contents of NFPA 86C are now primarily found in Chapter 11 of NFPA 86. A notable change is that NFPA 86 recommends that users of Class C furnaces include a low temperature alarm panel to indicate an overdraw condition on the ambient air vaporizers used for emergency purging. Previously, NFPA 86C required the use of a low temperature flow-restricting device that could potentially limit available purging capacity. Air Products' PURIFIRE® nitrogen supply monitoring system is designed to help you comply with this new recommendation.

Users of furnaces with special processing and flammable atmospheres should fully understand the requirements and recommendations of NFPA 86 and determine how the changes from the old NFPA 86C may affect their furnace operations. For help in understanding these specifications or for more information about our PURIFIRE nitrogen supply monitoring system, contact us at 800-654-4567.

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