API 650 - EN Specifications not Permitted JR 1

[Clamont]

Dear All,

In Section 4.2 of API 650 it only permits the use of J0 and J2 plates for the grades 275 and 355 but does not mention anything about using the more common JR. Can someone please explain why this is?

Thanks

 

[JStephen]

Using Google a bit, I find that "The JR, J0 & J2 suffixes refer to different impact requirements." It looks like the JR grade has impact properties applicable at 20 degrees C. I assume then that the issue is that they are concerned that a lack of toughness at lower temperatures would make the tank subject to brittle-fracture failure.

 

[Clamont]

JStephen,

Thanks for your reply.... I came to the same conclusion however cannot understand why they would not add an additional clause relating to the temperature. For example I am based in a country when it never drops below 20 Degrees and JR is by far the most common steel and according to the standards we are not allowed to use it.

Seems like an odd one!!

 

[fegenbush]

Clamont,

If you would like to have the grade added to the standard, you can issue an inquiry to the subcommittee on aboveground storage tanks. The procedure for doing so is listed in Annex D of API 650. The next meeting is in November 2014 and it will be brought up then. It is likely that an agenda item will be taken out to include the grade. If it comes up during the meeting, I will handle it myself if necessary. The standard is experience based, and there are certainly areas of the world who are under-represented on the committee.

 

[Clamont]

Thanks Fegenbush.... I will do so!

 

[jrluhar]

Dear All, can any one help me for below query,
IF some tank data sheet shows tank specification as S275JR then which material group to be considered as per Table 4.4a-Material group.
Material group is important as stress reliving shall be considered accordingly.
Thanks