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UW 2 List of Fluids with pressures 3

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bmoorthy

Mechanical
May 29, 2003
457
Is there a list of fluids or fluids with specific charectristics that are considered lethal (In Public Domain or available for Purchase) from the point of view of UW2 or ASME sec VIII Div 1.

For example, if i need to find whether my application is Lethal or not, how would i go about

(Yes, i know that process data sheet would indicate, but how does the process personnel decide, he does not know intricate details of ASME Sec VIII)

GAS at 200 BAR that has 20000 PPM of H2S-- Is this Lethal service-- Offshore platform.
 
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It's the owner's call. There is no rule to my knowledge which says that mixtures of an IDLH of XXX or below are immediately considered lethal service. IDLH is used as a guide, along with previous experience handling the material etc.
 
FYI

I believe that in the new Section XII (Transport Tanks)the service restrictions in TW-100.1 are based on UN packing group. This paragraph is much similar to UW-2 in Section VIII-1 but does not leave the option to the owner. This paragraph may give some guidance as to when to call for lethal service.

In the 3000 or so vessel designs that I have seen there was only 1 that was designated lethal service. There were many of those that were listed for sour service with design, inspection and testing requirements called for which are equivalent to lethal service but the owner did not want to call it lethal.

I think it has something to do with liability but that is only a guess.

Bottom line, designation of lethal service is an agreement between the owner, designer, and manufacturer.

EJL
 
Obtain the Material Safety Data Sheet for the fluids associated with specific projects.

The term lethal is not very precise. Helium is non toxic and not listed on the NIOSH IDLH list. However, being left in a tightly closed room with a helium cylinder and leaky pressure regulator would lead to asphixiation. The lack of oxygen would be the killer, not the helium. The victim would be just as dead as if killed by a toxic nerve agent.

We mostly deal with fluid mixtures not pure fluids. The mixtures are less easily defined in terms of IDLH, etc. Plants provide some data for particular types of units. Such data is often identified in site specific safety training. You can download lots of generic MSDS information off the web.
 
bmoorthy,

Is there a list of fluids or fluids with specific charectristics that are considered lethal (In Public Domain or available for Purchase) from the point of view of UW2 or ASME sec VIII Div 1.
It is only when I reread your question that I noticed "from the point of view of UW2 or ASME sec VIII Div 1" in your post above. Just for clarity, the NIOSH link I provided is NOT from the point of view of ASME.

I fully agree with moltenmetal that the Owner is responsible for identifying vessels that are in "Lethal Service". ASME VIII-1 UW-2 is quite clear on this...

"When a vessel is to contain fluids of such a nature that a very small amount mixed or unmixed with air is dangerous to life when inhaled, it shall be the responsibility of the user and/or his designated agent to determine if it is lethal. If determined as lethal, the user and/or his designated agent [see U-2(a)] shall so advise the designer and/or Manufacturer. It shall be the responsibility of the Manufacturer to comply with the applicable Code provisions"
 
There is one problem with lethal substance classification in that it gets real tricky if one has a fluid that isn't classified lethal and another company does and there is an event on your site.

Here is the OSHA Z-1 list. If your fluid is on this list there should a review of the classification of equipment to prevent any exposure to insure compliance.

 
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