#  > Petroleum Industry Zone >  > Pipeline And Fluid Flow >  >  >  Spiral welded pipe or longitudinal?

## pipeline

I'm currently specifying a pipeline to transport LNG. I priced the welded pipe and seamless, and the former is more expensive than the second. 
Now there is someone who can help me by providing some technical document justifying that kind of welded pipe is better (helical or longitudinal seam)? This from the standpoint of corrosion, easy to build in valve stations, etc.? 
Thanks in advance


pipelineSee More: Spiral welded pipe or longitudinal?

----------


## duddek

Hello....

Seamless is more cheaper than welded pipe. Welded pipe contains 2 types, spiral and longitudinal welded pipe, this is related with the application and depends on WT (wall thickness) or OD (diameter). I am working on this fabrication, you can check our company profile: **[link Point to another website Only the registered members can access]
*link*




<![CDATA[[Only Registered And Activated Users Can See Links]. 
Just an example for the application, Spiral pipes used for piling construction, such as for foundation of the bridge, or highways, or water pipelines, etc. while for longitudinal pipe used for oil and gas piling construction, jack up barge, shipyard construction, etc.
Actually its all depends on what you want to used with consideration on OD and WT.
There is specs for piping fabrication that you can refer to API 5L for pipeline and API 2 B for tubular. 
comparison for spiral and longitudinal welded pipe and seamless is,
OD = Seamless < Spiral Welded Pipe < Longitudinal welded pipe
WT = Seamless < Spiral Welded Pipe < Longitudinal welded pipe
Length = Seamless has the nominal length between 6 meter and 12 meter only.
             Spiral has maximum length, can fabricate to 50 meter and more.
             Longitudinal has maximum length also but the circum per each can need to be joint into 1 tubular and to pipelines.
method = Seamless used hot process, Spiral used cold rolling with extrusion process while longitudinal used cold process with bend and rolled. (can be process at humetal).

just for your information.....

----------


## duddek

> I'm currently specifying a pipeline to transport LNG. I priced the welded pipe and seamless, and the former is more expensive than the second. 
> Now there is someone who can help me by providing some technical document justifying that kind of welded pipe is better (helical or longitudinal seam)? This from the standpoint of corrosion, easy to build in valve stations, etc.? 
> Thanks in advance
> pipeline




While for transport LNG application,  this is consider to API 5L Monogram since it need to do Hydrotest also. You can prefer to spiral but consider to the OD and WT.
And related with corrosion you should prefer to material selection that you want to use, and easy to build in valve stations, I think, it is refer to the dimensional parameter that you want to set refer to standard of valve selection.

 :Big Grin:

----------


## Abdel Halim Galala

> I'm currently specifying a pipeline to transport LNG. I priced the welded pipe and seamless, and the former is more expensive than the second. 
> Now there is someone who can help me by providing some technical document justifying that kind of welded pipe is better (helical or longitudinal seam)? This from the standpoint of corrosion, easy to build in valve stations, etc.? 
> Thanks in advance
> pipeline



Seamless Pipe (no seam welding & no helical weld) is the most expensive than Seam Welded pipe (longitudinal seam weld). And Seam Welded Pipe is more expensive than Spiral Pipe (helical weld).
And for each type there is a joint efficiency E used in design equation, where for Seamless E = 1.0, and for Seam Welded E = 1.0 in case of full radiography and may be = 0.85 for other cases, and for spiral E = 0.65 or 0.60 (see ASME B31.4 for liquid pipeline & ASME B31.8 for gas pipeline). 

And no way to use spiral pipe in any flamable fluids like LNG pipelines, where you can use spiral type for brackish water or for lighting posts at public streets. We prefer to use seamless type, or seam welded type.

And the joint efficiency E has a great effect in determining the pipe wall thickness, where for smaller E will lead to higher pipe wall thickness and vice versa.
See the following solved examples at CR4 Fprum (note that each ASME code has its own design equation):
- ASME B31.4: **[link Point to another website Only the registered members can access]
*link*




<![CDATA[[Only Registered And Activated Users Can See Links] 
- ASME B31.3: **[link Point to another website Only the registered members can access]
*link*




<![CDATA[[Only Registered And Activated Users Can See Links]
- ASME B31.1: **[link Point to another website Only the registered members can access]
*link*




<![CDATA[[Only Registered And Activated Users Can See Links]
- API 5L Tolerances for Wall Thicknesses: **[link Point to another website Only the registered members can access]
*link*




<![CDATA[[Only Registered And Activated Users Can See Links]

----------


## duddek

> Seamless Pipe (no seam welding & no helical weld) is the most expensive than Seam Welded pipe (longitudinal seam weld). And Seam Welded Pipe is more expensive than Spiral Pipe (helical weld).
> And for each type there is a joint efficiency E used in design equation, where for Seamless E = 1.0, and for Seam Welded E = 1.0 in case of full radiography and may be = 0.85 for other cases, and for spiral E = 0.65 or 0.60 (see ASME B31.4 for liquid pipeline & ASME B31.8 for gas pipeline). 
> 
> And no way to use spiral pipe in any flamable fluids like LNG pipelines, where you can use spiral type for brackish water or for lighting posts at public streets. We prefer to use seamless type, or seam welded type.
> 
> And the joint efficiency E has a great effect in determining the pipe wall thickness, where for smaller E will lead to higher pipe wall thickness and vice versa.
> See the following solved examples at CR4 Fprum (note that each ASME code has its own design equation):
> - ASME B31.4: **[link Point to another website Only the registered members can access]
> *link*
> ...




Woww... I just know this from you sir.... that's cool. i can advance my knowledge here. and thanks for the link.  
Yeah, but i thought seamless pipe is more cheapest than spiral and seam welded coz its just using hot method during fabrication, same like slug or iron bar. And I ever saw that spiral also used for oil and it has flame-able characteristic, but not used for gas offcourse. Coz most of gas, was used small OD, and seamless pipes are preferable one. Is it correct or not? I don't have any idea, since it is really used at asia countries.

btw, do you have any ebooks, related with the basic calculation on spiral welding and long seam welding pipe? to find about the consumable flux, speed adjustment setting on the welding machine (SAW), and cycle time of the welding?... also ebook about basic calculation for bend and roll of steel material.

many thanks for the information sir.

Taqobalallohu minna wa minkum,...  Happy Id'l Fitri.

 :Smile:  :Smile:

----------


## melvin_magbanua

Based on my past experience for LNG pipeline application, seamless is always being specified.  Please review your B31.3 (for in-plant application-piping) and B31.4 (for transportation application-pipeline) standard, you will learn more info from there.

----------


## inzenjer

regards to all
i work in upstream surface segment of oil and gas production. seamless are always first choice. for seam welded pipe E = 1.0 looks optimistic. also some bending of pipes, very large diameter of bend for example 200x OD of pipe, is very often needed. in this cases welded pipe is not good choice.
inzenjer

----------


## duddek

> regards to all
> i work in upstream surface segment of oil and gas production. seamless are always first choice. for seam welded pipe E = 1.0 looks optimistic. also some bending of pipes, very large diameter of bend for example 200x OD of pipe, is very often needed. in this cases welded pipe is not good choice.
> inzenjer




Sorry all, due to my lack of knowledge about the real application of the pipe, since I was work at piping fabrication and don't really know for all the application of pipe that I made.

Once again, would you like to upload completely about ASME B31.3, B31.4 and B31.1, it seems have relation with the calculation and application of the pipe, right? So we will know about which pipe that preferable to used for LNG and other application.

Thanks

----------


## jns544

Regards to all

According to my experience, Seamless is also my first choice. For big diametres is difficult to find seamless pipes, so for LNG pipes we usually specify ASTM A358 Gr. 304 Cl.1 

Regards

----------


## James Lee

> I'm currently specifying a pipeline to transport LNG. I priced the welded pipe and seamless, and the former is more expensive than the second. 
> Now there is someone who can help me by providing some technical document justifying that kind of welded pipe is better (helical or longitudinal seam)? This from the standpoint of corrosion, easy to build in valve stations, etc.? 
> Thanks in advance
> pipeline



Hi,

I'm glad to see your messages on this forum and we can offer you LSAW,SSAW,DSAW,T-Pipes in good quality and competitive prices.Welcome your inquiries to my e-mail:JamesLee19841005@gmail.com and then I'll send you our best prices.We also have API&ISO and we can be your long-term supplier in China.I wish to have further talk with you on MSN and Skype.

Awaiting your good news!!!

James Lee

Best Rgds

E-mail:JamesLee19841005@gmail.com
MSN:James19841005@hotmail.com
Skype:jameslee12341
Cell Phone:86-15062509815

----------


## melvin_magbanua

I know you posted your query last February and by now you might have reach the final decision on which material specification to follow. But here's my last suggestions: the reply given by Abdel Halim Galala was totally correct, and you have to do your exercise in checking the cost/price difference between the Seamless & the ERW pipes (ERW is a lot cheaper than Seamless).  Seamless normally takes a longer time to order compared with ERW pipes, normally lots of pipe manufacturers available producing ERW than Seamless. Be careful with Pipes manufactured from China, you must specify factory test (metallurgy and mechanical) before delivery.

----------


## wpamungkas

Hello
What is the price difference between seamless and welded (LSAW and DSAW) in general for the same diameter of the pipes?

----------


## melvin_magbanua

Depending in your geographical location. Do an exercise by sending inquiries from different pipe manufacturer close to our area.  Try to compare too the prices from a manufacturer based in China, they are normally cheaper, however the quality Control has to be stringent and monitored closely. I hope this answer's your question.

See More: Spiral welded pipe or longitudinal?

----------

