ASME B31.3 or B31.4 for aqueduct?? 1

[GermanJoel]

Hello dear colleagues, I have a problem that I hope you can help me please. We are designing a pipeline for water running from the head of a river to a facility of an ammonia plant, the length of the pipeline is about 13 km and it’s totally buried, I’m not sure whether to use ASME B31.3 o ASME B31.4. What do you think?? And if it’s necessary to do an stress analysis?? All your comments and help will be greatly appreciated.

 

[LittleInch]

The key here are the words "pipeline", "buried" and outside plant.

B 31.4 is much better at buried pipeline and will yield a more optimised design.

Unless you have large temperature differences or large bending moments, you can do the simple fully restrained stress analysis in 31.4.

There are many other water specific pipeline codes as well and if you're using something other than welded steel, (e.g. ductile iron, PE etc, you might be better off with whatever the local water authority use.

some idea of size and pressure would help to define it better.





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

 

[GermanJoel]

Little Inch, thanks a lot for your response!! you're right, I just have red this:

In B 31.4, "400.1.2 This Code was not developed to apply to
(a) building service piping, [highlight #FCE94F]such as water[/highlight], air, or steam..."

and in B 31.3. "300.1.1 ...(b) This Code applies to piping for all fluids, including:
(1) raw, intermediate, and finished chemicals;
(2) petroleum products;
(3) gas, steam, air,[highlight #FCE94F] and water[/highlight]..."

What do you think about it?? that's why I'm not sure which one to use, the pipe I'm working on is for transporting water to the ammonia plant

 

[DekDee]

Your piping is not "building service piping" so that clause is not applicable to your situation.

 

[BigInch]

As you can also see B31.3 can be used for petroleum products, gas, steam, water and air, but not if you're building a pipeline.

It wouldn't be process water until you mix it with your ammonia. Isn't this really just a water pipeline? AWWA is typically used for water pipelines.

http://www.awwa.org/publications/manuals-of-practice.aspx

If you don't want AWWA for some reason or other, use B31.4 and take all appropriate additional measures for water.

 

[LittleInch]

GermanJoel,

you seem to have skipped over the bit in the intro to B 41.4 as noted below which summarise it better than I ever could.

B31.3 Process Piping: piping typically found in petroleum refineries; chemical, pharmaceutical,
textile, paper, semiconductor, and cryogenic plants; and related processing plants
and terminals.

B31.4 Pipeline Transportation Systems for Liquids and Slurries: piping transporting products
that are predominately liquid between facilities, plants, and terminals, and
within terminals, pumping, regulating, and metering stations.

In your section the key words are "building service piping". You are talking about a 13km buried PIPELINE. B 31.4 covers that better than B 31.3, but as noted above by me and others, it (B31.4) is predominantly used in hydrocarbon and chemical service, whereas water, as a low hazard substance, has its own set of codes specific to water only which are even more specific and ultimately more attuned to water pipelines than even B 31.4 - hence cheaper.

You haven't given us:
Diameter of your pipe
Pressure of your pipe
Flow rate of the water
Your planned pipe material (if you already know it)
Where in the world you are building this.

All these will have an impact on which design code is "best" for your application.


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

 

[GermanJoel]

First of all I want to thank you all for your comments, they are really helpfull!!. Well, this pipe is intended to be designed for 13.5 km length, 14" diameter, 370 psi design pressure, to take 510 m3/h of water approximately, the material is ASTM A-106 Gr. B, the pipe is completely buried and this proyect is located in Bolivia (South America), What do you think Colleagues?? Which other codes would be good for it??

 

[LittleInch]

The current pressure is a bit high for PE, but if you went up in size a little bit I'm sure you could run this in PE, in which case you really need a water pipeline code to make best use of the material. AWWA have some good ones, but I'm pretty sure the Bolivians will have their own version / favourites.

BTW 14" is generally regarded as an "odd" size and hence normally not used - 16" would be much better and fittings etc easier to get.

however for Steel lines, B 31.4 is about as good as it gets and is certainly a good start point if nothing else.

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

 

[GermanJoel]

Thanks LittleInch!! I have to clarify that the pipe (aqueduct) is made of steel according to ASTM A-106 Gr.B, we have used ASME B31.4 for design of pipelines but our Japanese client wants us to use B31.3, another interrogant is if it's really necessary to do the analysis of stress, in both cases B31.3 or B31.4??

 

[weldstan]

While AWWA would be the logical choice, I have seen B31.3 used for similar applications.

 

[LittleInch]

Just work out the cost of both and present them to your client and then ask him to choose....

If he wants to pay more money for the same product then fine, his money, his choice.

Stress analysis of buried lines is much better described by 31.4. 31,3 is a very good PIPING code, 31.4 is a decent PIPELINE code.

If you don't have a big temperature change then stress shouldn't be an issue.

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

 

[larssonlahcen]

hello i'm new in this group,I work in factory ammonica and we work with B31.3

 

[BigInch]

That's because it's not a pipeline.