EFW Vs SMLS 1

[MohdYaseen2010]

Dears;

Our Contractor is seeking for changing our plant piping materials from SMLS to EFW.
As I know the Seam (EFW) pipes are used in low pressure and medium pressure applications while the SMLS is utilized for the high pressure application.
My queries;
1- To which value can I classify the system is low, medium or high pressure?
2- Is there any standard that limiting the utilize the EFW pipes to a certain pressure application?

Mohd Yaseen

 

[weldstan]

Both seamless and welded pipe are used for high and low pressures.

 

[EdStainless]

You need to look at the materials and the specifications involved.
Look especially at the NDT required, you may want to require more testing.
There is just as much bad seamless product out there as welded.
I hope that you plan to audit and witness testing on this product.

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P.E. Metallurgy, Plymouth Tube

 

[mk3223]

The Code doesn't limit the application of the EFW pipe in any pressure rating.
IMO, the EFW pipe application may be based on the pipe thickness due to the longitudinal weld joint quality factor, and the industrial experience due to the safety and reliability issues of the critical process application.

 

[LittleInch]

So what is the design code?

Are you changing existing plant piping material specifications?

The issue is that B 31.3, for some reason, still doesn't like Welded pipe.

Table 302.3.4 has longitudinal weld joint quality factors for different types of welded pipe.
EFW is 0.95, but can be raised to 1.0 with additional radiography. Therefore for EFW there should be only a small or no difference in wall thickness or other stress factor.

There is no limitation on pressure for different types of pipe as you describe in any international design code I am aware of.

What is written into your own company standards (or those of any other company which you use) or piping material specifications is something completely different.

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

 

[MohdYaseen2010]

Dears All;

Thanks for your interventions;
our Case is belong to change pipe material from SMLS A106 Gr. B (with 3mm INCONEL625 Overlay Welded) to EFW ASTM A928-S32750 CLASS 1 Ej=1.0 (cause of lengthy production schedule for the original materials).
As highlighted by LittleInch, the weld joint quality factors (Ej) for the alternative materials is 1, so the Examination Additionally 100% radiographed per
para. 344.5.1 and Table 341.3.2 will be applied.
As long as the original material is Carbon Steel lined with 3mm INCONEL625 we presumed that the alternative elected material (Duplex Stainless Steel) is having the same characteristics of the original material that can be utilized to deal with the transported medium. Our doubts focused on the Manufacturing Type (SMLS Vs EFW) whereas the design pressure for the system is 4MPa & base on most of the responses seems that there is no matter whilst using EFW as long as the pipe designed base on the design parameters.

Mohd Yaseen

 

[MJCronin]

This is the scary part of the question-answer process where the initial simple question explodes into much more complexity ....

MJCronin
Sr. Process Engineer

 

[Latexman]

This is the scary part of the question-answer process where the initial simple question explodes into much more complexity ....

Exactly. Dorothy just landed in Oz.

Good luck,
Latexman

Engineers helping Engineers

 

[LittleInch]

Errr, Duplex has different characteristics to C Stl, especially at even quite low temps of 70+ Deg C where the SMYs falls off rapidly compared to C Stl.





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

 

[EdStainless]

The duplex will have restricted temperature range (both high and low), higher thermal expansion, lower heat transfer, and a bunch of other differences also.
You are going to require A923 testing correct?
The biggest issue with this alloy is assuring that the anneal and quench were done correctly.
If not then serious degradation in both toughness and corrosion resistance will result.

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P.E. Metallurgy, Plymouth Tube