Location class 4 x ASME and Location 5 for ISO

[FilippoT]

Hi,
ASME 31.8 location class 4 and ISO 13623 location class 5 have the same definition that states "when four building are prevalent and heavy traffic is present and undergdound facilities are present". Is anybody aware of references where these three requirements are stated to be present at the same time for the application of ASME class 4 or ISO class 5.

 

[LittleInch]

The location classes are intended to be a conservative version of a risk assessment.

ASME 31.8 class 4 /ISO class 5 is a descriptive definition and should not be taken too literally.

If in doubt you are supposed to take the most conservative view.

Is your question about whether you need all three to be present to make it a class 4 location?

Any one would make it a class 4 for me.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[1503-44]

"Location Class 4 includes areas where ..."
1.) The word "includes" is the key word. So read it turned around.
It does not EXCLUDE places that have "more than 10 but fewer than 46 buildings, where traffic is heavy or dense, and where other utilities may be present.
2.) The location of the comma is also significant. The comma where it is means that Class 4 also includes areas that have numerous underground utilities, even though they may not have either heavy traffic, or a large number of buildings. In other words, it means that class 4 might contain ONLY a pipeline crossing a heavily travelled freeway.

If you still have doubts, look at 840.4 "INTENT"

"It should be emphasized that Location Class (1, 2,
3, or 4) ... is defined as the general description of a geographic area having certain characteristics"

Therefore, being a general description only of geographic charastics, it does not specifically list any specific requirements at all, certainly nones so specific that would make it class 4 only when two or more of them might happen to be true at the same time.

Now again they remind us, in the exact same paragraph, that this "A numbered Location Class ... refers only to "the geography" of that or a similar area. How can you take anything as a specific requirement necessary to determine a class 1,2,3, or 4 location? There are no specific requirements. If it simply looks like a class 4, its a class 4. If it walks like a duck, its a duck.

Now we get to part (b)
"(b) When classifying locations for determining the
design factor for pipeline construction and testing that
should be prescribed, due consideration shall be given
to the possibility of future development of the area."

Considering "future development", if you looked at an area where 4 story buildings were prevalent, but called it a class 3, because traffic didn't look particularly heavy on the day you visited, or that it did have heavy traffic, but did not have any other underground utility, it would be difficult to say that traffic wouldn't get heavy within a month, or that another utility could not be constructed tomorrow. There are very few places where four story buildings are prevalent, but not a lot of other underground utilities too. Water, sewer, telephone, electic. You're adding gas. That's 5 right there.

A black swan to a turkey is a white swan to the butcher.