Min Design Of API 5L GR.B

[AliGrailly]

Hi engineers


According to code b31.3 table A1 for material API 5L GR.B , column min design , just mentioned "B" what is that? the min design is -29C?

In other notes including 56,57 also state not to use this type of material for temp above 425 C

In some tables in this column there is "A"

 

[david339933]

Read the Code.

 

[AliGrailly]

I think it means ref to 323.2.2A curves ( A to D ) and use service design temp-thk combination to know it required or not
In note3 of 323.2.2A mentioned not required impact test when temp below -29C and stress ratio less than 0.3 for carbon ( it means Ex temp be -28 , -26 ,... 0 )
but not listed any para in b31.3

If possible make an example for service design temp -20 with design pressure of 128bar for material A671-cc65

 

[david339933]

You need to read the Code. You are referencing Figures and Tables, but read the actual section 323.2.2
You are flooding this site with your somewhat simple questions. Not really what this site is for. Get some books, research, etc...then come back if you have particular questions.

 

[BenMacier]

API 5L grade B is such a basic quality steel pipe material, I am wondering what you are planning to transport with it.


* Finding a solution is great * Knowing how to implement it is fantastic * Believing it is the only one and best is naive ?

 

[1503-44]

A = 30,000 psi yield strength
B = 35,000 psi yield strength

Most of this type of pipe produced today will have a higher yield, 42-52 ksi, and can come with double or triple certifications.

 

[LittleInch]

He means the min tem where ther eis a letter, not a number.

Note 6 says

"For
carbon steels with a letter designation in the Min. Temp.
column, see para. 323.2.2(e) and the applicable curve
and Notes in Figure 323.2.2A"

This is the curve and note that the min temp changes with thickness of the pipe. If you're above the line you don't need to do impact testing is my interpretation of this clause.

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

 

[1503-44]

Of course. Now that makes sense. Thanks.

Yes. Above the line it is not required.

 

[SJones]

Just a word of caution if looking at toughness requirements: thread378-482418

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/in/drstevejones

All answers are personal opinions only and are in no way connected with any employer.

 

[MickMc]

LI is correct in his interpretation and the notes accompanying table important, be careful if you are defining your piping class minimum temp (API 5L GrB) as -29°C as it is related to wall thickness. I would steer away from Stress Ratio except for short term conditions where you will have to demonstrate that you can meet the 3 conditions 3.2.2.b the 3rd being combined stresses which can only be evaluated when routing is finalised.