Oxygen Tanks

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augie47

augie47

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State Electrical Inspector (Retired)
I know that most inspectors are like myself and do not classify areas, however, I was called to a facility where they fill gaseous & liquid oxygen tanks for home use. They have a bank of oxygen gas tanks connected to a manifold and the fill smaller tanks from the larger ones. They also transfer liquid oxygen from larger (180 liter) tanks to smaller ones.
I was asked the general question as to how this building would need to be wired. In all my reference books there is no reference to oxygen
Would this facility be a hazardous classified area ??.
 
this doesnt really answer your question, but I have done servie call work in a differnt "Hooks Oxygen" buildings, and they do not have any special classified areas in the building, its all piped in emt...
 
While oxygen enrichment certainly increases the magnitude of the potential fire hazard, enrichment alone does not create a hazardous location. It is the ?fuel? element of the fire triangle that determines Classification. In other words, the location would already have to be Classified because of the fuel; oxygen enrichment simply makes it more dangerous.
 
This beast won't go away. The local Fire Marshall has provided me with a page from NFPA53 which states that wiring in an "oxygen enriched atmosphere" will be class 1 Div 1, but I have doubts this situation falls under NFPA53. Any input, guys ??
 
oxgyen

oxgyen

My research show's that we can't live without it. I know that has absolutely nothing to do with the question. It is my personal belief that it (alone) has no explosive charteristic's. But, quite obviously does enhance the fuel, heat syndrome. NON-classified is my humble answer.:roll:
 
We're doing a tank farm now that has a huge liquid oxygen dewer. This is an inspected job with more engineers than you can shake a stick at and nobody has said a thing about classification. Everything existing or new is just EMT.

-John
 
NFPA 53 is a Recommended Practice. According to the latest NFPA Regulations Governing Committee Projects a Recommended Practice is ?A document similar in content and structure to a code or standard but that contains only nonmandatory provisions using the word ?should? to indicate recommendations in the body of the text.? [rba note: underline added] In the interest of full disclosure virtually every document that deals with general electrical area classification practice, e.g. NFPA 497 or API RP500, is also a ?Recommended Practice.?

I was not familiar with NFPA 53 before today. (The link is to the free online version) It isn?t particularly long so I read the material relevant to the OP.

The Scope and Purpose statements (Sections 1.1 and 1.2) are fairly general and lack the specificity that usually required; nevertheless, the ?Application? statement (Section 1.3) and the Definition of OEAs (Section 3.3.25) seem to vaguely apply to the OP.

The first question then is ?under normal operation and design conditions does the area under concern meet the definition of a OEA?? I seriously doubt it.

The Fire Marshall appears to be citing Sections 7.7.2 and 7.7.3. It appears that the NFPA 53 TC is actually unfamiliar the NEC. They cite Article 500 rather than 501 for installation practices. The do recognize in 7.7.2 that that the location should already be classified according to the ?fuel.? However, using Division 1 installation techniques will make absolutely no difference unless the location needed to be classified in the first place because of the ?fuel? involved.
 
augie47 said:
I know that most inspectors are like myself and do not classify areas, however, I was called to a facility where they fill gaseous & liquid oxygen tanks for home use. They have a bank of oxygen gas tanks connected to a manifold and the fill smaller tanks from the larger ones. They also transfer liquid oxygen from larger (180 liter) tanks to smaller ones.
I was asked the general question as to how this building would need to be wired. In all my reference books there is no reference to oxygen
Would this facility be a hazardous classified area ??.
Click to expand...

The NEC does not care one whit about how much oxygen is in the area, only what fuels might be there.

I am not suggesting that the oxygen might or might not present an additional hazard, only that the NEC does not care.

It is kind of like when dealing with explosives. There is obviously a hazard, but the NEC does not deal with it.
 
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