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rhirsch (Mechanical) (OP)
6 Nov 08 19:53
Hi,

I would be cool with any cert that I would need to do, if I knew if I needed it, and which one.

I am building a machine, and I will certainly need to follow NFPA 79, becuase its a machine with a control box. fine.

Here is my question: The machine will not be used in a hazardous location. However the machine will pump hydrogen electrochemically (no moving parts).

There is no oxygen in the gas stream, so to only chance for explosion is if there is a failure. For this I have fans that cycle many volumes of air through the pump area and I have an H2 detector which cuts power to everything (except the fans). Further the electronics enclosure is separate from the pump area.

I realize certs are not by law and are only required by customers, but does a system like this need ATEX certs or anything? Or does the fact that there is never a concentration of H2 that could cause an explosion be enough?

I understand that there are many systems that work with H2, but use enclosure volume replacement rates great enough to not require hazardous location certs nor intrinsically safe equipment. Is this right?
DonPhillips (Structural)
6 Nov 08 20:05
I am not hip to machines but if equipment is typically installed in a building, it usually has to be listed, and installed per its listing, and this is a building code requirement (or a law).  Figuring out what listing you will need probably has more to do with its final application.  Some processes and its equipment are exempt in some codes in some states (someone else oversees these and in some states, it is self regulated).

Also keep in mind if there is no certification, then you have a higer burden of proof to defend yourself, should you get sued, that you used reasonable care in designing your machine.  Designing it to a standard and get it certified against that standard could be proof of reasonable care of the design.  Manufacturing defects are another issue.  User mistakes, including abuses and lack of maintanence, are another.  

Even if your client does not require a certification, I suggest you seek something to ensure you are limiting your liability as much as you reasonably can.   

Don Phillips
http://worthingtonengineering.com

rhirsch (Mechanical) (OP)
6 Nov 08 20:27
OK, I agree with all that and I know I need NFPA 79. But I am asking if it sounds like my machine needs some sort of hazardous location certs. I would like to know if these certs would be needed to address the very concern you are talking about: certified safety.

But if I have obviated the need for these certs then great.
JLSeagull (Electrical)
7 Nov 08 7:42
Depending upon the application, certification may be required by OSHA.  Search for the phrase nationally recognized testing laboratory.  These independent organizations help to determine whether or not products meet various "conscensus-based standards".  For an offbeat example the HVAC on an analyzer shelter in a hazardous is certified (ETS Listed) by a company called Intertek Testing Services to verify compliance with UL and CSA codes and standards for use in a hazardous location.  See the OSHA requirement for third party certificaction under US title 29 CFR 1910.307.  A well known testing lab is TUV.

http://www.osha.gov/dts/otpca/nrtl/its.html

http://www.osha.gov/dts/otpca/nrtl/tuvam.html

http://www.osha.gov/dts/otpca/nrtl/met.html
rhirsch (Mechanical) (OP)
7 Nov 08 10:23
thank you that was helpful.
BJC (Electrical)
10 Nov 08 14:30
"I realize certs are not by law and are only required by customers"

Not True- Local building codes typically require equipment to be "Listed"  Usually by UL.  IF the machine is piped into the place it may have to pass the mechanical inspection as well.  They may require a NEMA certification as well. Insurance companies have a voice as well. The don't usually OK projects but they do inspections from time to time. They won't be happy if they see something without some kind of Testing LAb lable on it.
Lc

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