API 500 Classification Rules - Interpretaton

[cod]

Our company does a good deal of work on marine termianls handling petroleum and its products. Sometimes the API rules are very difficult to interpret in view of reality. Consider API 500 Figure 96 where it is stated "Outdoors - Piping with Valves, Screwed Fittings, Flanges or Similar accessories...etc" should be classified as a Div 2 location in the open air. In the case where a pier is some distance offshore and is accessed by a long trestle with half a dozen pipes joined by flanges (or screwed fittings) handling volatile liquids, following these rules, the entire trestle would have to be classified because of staggered joints in the pipes. This is unreasonable but using this API rule, an AHJ would require just that even though this standard is labeled as "Recommended Practices".
Or, am I reading the Recommended Practice wrongly??

Any help on this question of clasifying flanged piping, especially from past or present API members would be greatly appreciated.

Charlie D.

 

[Kiribanda]

cod,
Normally per API 500 such pipe line installations in typical oil terminals are classified as Div 2.If you say it is "inreasonable",then on what grounds do you classify such an installation as "unclassified" or "safe" area?Also could you install spark producing electrical equipment in such an installation without following hazardous installations rules?

 

[cod]

I'll go back to my previous example where multiple flanged pipelines are installed on a trestle with overlapping flanged sections.

Yes, there are many spark producing items that would be on the trestle including vehicle engines of all types, employees with un-approved equipment (flashlights, phones, etc) non-explosion proof lighting, communication systems, etc. What I cite is what can be seen on any, if not all trestles serving marine oil terminals. Such trestles are simply regarded as non-hazardous areas. In fact, one common design practice is to place the marine operations office, standby generators, fire pumps and other such items on the trestle just outside of the terminal's loading/unloading area just to allow ordinary wiring and electrical equipment to be used. How about tank farms? Granted, inside tank berms hazardous areas are necessary, but outside of berms, flanged piping may even run through public (but guarded) areas. From my experience, I have never seen pipe flanges being a reason for declaring an area hazardous. At a time when flanges are broken open for pipe repairs or other reason, the immediate area would be roped off as hazardous in accordance with the terminal's published Maintenance and Operations Rules for hot work.

Thanks for your kind reply and let's hope for other comments to be posted.

Charlie D.