Vapor Combustion Unit

[DAWN555]

We are going to install a vapor combustion unit (VCU) for a tank and its loading system. It will be natural draft. Basically a burner at the bottom of a stack. We are having a discussion about whether NFPA 86 or some other NFPA code would cover it. When I look at it, there is a burner inside a tube which would supply confinement so I think it would be. There are others with the opinion it is not covered and therefore does not need the double block and BMS of NFPA 86. Is there any guidance or interpretations by NFPA or others on whether it is or what safety systems are required

Thanks

 

[FacEngrPE]

Jogn Zink's solution includes flame scanners, usually that indicates NFPA 86 Standard for Ovens and Furnaces is part of the design. I would not quibble about the cost of the flame safety system, it is good insurance against mis-opperation.

NFPA 86 scope (partial):
This standard shall apply to Class A, Class B, Class C, and Class D ovens, dryers, and furnaces; thermal oxidizers; and any other heated systems and related equipment used for processing of materials.

https://www.johnzinkhamworthy.com/products-applications/vapor-control/vapor-combustion-systems/

 

[DTM1966]

I agree that it is best practice. I am getting pushback from the project group who have gotten a quote without the double blocks and Flame safety system required under NFPA 86. I was looking for some guidance specifically stating the VCU is covered under 86

It is interesting that the picture above does not show double blocks on the fuel gas or waste gas lines which would be required under NFPA 86