B31.3 inplace of B31.4

[nickypaliwal]

we have a requirement for 18" and 20" ISO 3183 Gr L415, PSL2 (SMLS/LSAW/HFW) however the required length is very small so we want to use B31.3 material.

What major concerns related to material and material testing should be taken care other than mechanical testing requirements (tensile, pressure, thickness etc).

Nickypaliwal

Materials & Corrosion Engineer

 

[LittleInch]

I understand the question, but there is no such thing as "B31.3 material". If you look in B31.3 you will find literally hundreds of different options of materials.

Which material did you mean.??

The pipe doesn't care which code it is being designed to, but a lower strength material ( say A105) will require thicker pipe than your L415 (X60) material.

you are concerned about ductility, low temp strength and weldability.

you can do a comparison between the material specs when you know what the material is you're trying to buy.



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

 

[pennpiper]

nickypaliwal,
You wrote:
"however the required length is very small so we want to use B31.3 material."
1, How small is very small
2, What is upstream and what is downstream of very small?
3, Can you provide a sketch?

Sometimes its possible to do all the right things and still get bad results

 

[weldstan]

By shifting to B31.3, your design thickness may be greater than that achievable with B31.4 depending on location.

 

[zdas04]

In my mind the key difference between the two codes is that the pipeline code acknowledges that population density can change along a pipe route, and the design needs to accommodate those changes. A plant is located where it is located, and must anticipate that the local population may increase with time. If you design a B31.4 line using the maximum population density you will get about the same wall thickness as you would get with B31.3. I think that you just have to pick a set of calcs and document why you picked those calculations.

[bold]David Simpson, PE[/bold]
MuleShoe Engineering

In questions of science, the authority of a thousand is not worth the humble reasoning of a single individual. Galileo Galilei, Italian Physicist

 

[LittleInch]

Zdas04 - surely you mean B31.8?? B 31.4 has no population density calcs within it.

For a materials and corrosion engineer to refer to something as vague as "B31.3 material" compared to the detailed description of the line pipe is a little worrying....

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

 

[zdas04]

B31.8 is the code I'm most familiar with. I had it in my mind that B31.4 had the same location class table, but it has probably been 15 years since I looked at it and that wasn't in much detail.

[bold]David Simpson, PE[/bold]
MuleShoe Engineering

In questions of science, the authority of a thousand is not worth the humble reasoning of a single individual. Galileo Galilei, Italian Physicist

 

[pennpiper]

nickypaliwal,
You have not had time yet to respond to the people who have asked questions or offered comments. You, no doubt are very busy.
-
However here are some added questions to my original list:
4. Where are you, what City? and what Country?
5. Where is this project, Onshore? Off Shore? Inside the fence? outside the fence? Near what City? and What Country?
6. What is the Commodity?
7. What is the purpose of this line?


Sometimes its possible to do all the right things and still get bad results

 

[BigInch]

You can't use any provision of B31.3 if your contractual or legally required design code is B31.4
Use of B31.3 pipe might be considered only if B31.3 resulted in thicker pipe than that required by B31.4, so conditional use of B31.3 would have to result in at least a thickness equal to that for B31.4, but most likely even thicker.

B31.4 has never, never, ever had class locations.

Reaction to change doesn't stop it

 

[KevinNZ]

ISO 3183 is a pipe material code not a design code. What is the design code you are using? It the design code that will list other pipe materials you can use. But these new design calculations and may need thicker wall.

ISO 3183 is derived from API 5L so there would be other pipe grades listed in 3183 that may be easier to source.

Material has to be listed in your design code for you to use it. There would be rules on using non listed materials.

 

[nickypaliwal]

Appreciate your response. Please see below details, I will try to answer all the questions as there are too many.

Piping that we plan to use is - A106 GrB.

Location is Oman. The length of pipe required is 24m and 12m for 20" and 18" respectively.

The service is hydrocarbon and the area is not far from main station.

Sketch and other details are still to be looked upon however the understanding that we have is to compare the high level requirements in both the codes related to material testing and composition restrictions, so that a learned decision can be made. We plan to ask for the possible testing and assess risk to accept the piping material.

I might have missed to answer many of above queries which I can answer once I start with the detailed study of the matter.

Nickypaliwal

Materials & Corrosion Engineer

 

[MickMc]

As most of the responses have said design it to the relevant code (main station therefore pipeline B31.4/B31.8/DNV??) using the relevant equation, a quick search through B31.4 & B31.8 references A106 piping as does B31.3. Typically B31.4 would give you thinner allowable wall thickness but you do not say what your hydrocarbon service is.

 

[SJones]

Is it not that the question is more along the lines of: "if we have to go to a stockist for ASTM pipe, what activities will be necessary to achieve an identical or superior perception of pipe quality and reliability to that achieved by API Spec 5L PSL 2 (without sour service)?"

The mechanical property side of things will be straightforward; it's the NDT that will get problematic.

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/pub/8/83b/b04

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

 

[LittleInch]

That is a remarkably short length....

ASME B31.4 section 423 specifies what you need to do.

Although you might not need the low temperature requirements, A333 is typically available from stockists as is A106, both of them listed in the table in B 31.4 table 423.1.1. as allowable materials.



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

 

[nickypaliwal]

Sorry Gents, I am trying to collect more information but due to some reasons in office , the link is broken.

Nickypaliwal

Materials & Corrosion Engineer