roughness pipeline

[EduardoPerez]

1.- Ref Brisbane (petroleum ),28 March ; 16:25
Please , confirm that 1000 inches or 0.025 mm (25 microns) ia a good safe design for a gas pipeline of 42" inches and 300 km as you mentioned in the above ref. (without internal coating).
2.- What is a typical roughness of piping when delivered at factory ?
3.- Do I need to specify a guaranteed roughness for the manufacturing of piping and what should be the most convenient value in microns ?
4.- Is there any protection recommended to avoid corrosion ( higher roughness) during transportation and storage in yards before installing it ?
5.- What is a typical roughness in gas pipelines during its years of operation ?
6.- Does regular pigging improve roughness during the gas pipeline operation ?
7.- Having a margin in design with 45 microns is good for the life expectancy of the pipline operation (25 years) ?
8.-Does Corrosion Inhibitor pigs (like V-Jet corrosion inhibitor from TDW) reduce pipeline deterioration (roughness) ?
9.- Confirm that pigs can be used to apply internal pipe coatings ,such as epoxy coatings materials, in operating pipelines and that pigs may also be used with corrosion inhibitors to distribute and coat the internal wetted perimeter.-
10.- Are multicup urethane type internal- coating pigs the most used ?
11.- Internal coatings are widely use in gas transmission lines ?
12.- What type of internal coatings are mostly used ?
13.- Internal coatings have operations problems due to pigging or for some other reason ?

 

[LittleInch]

What is this exactly - a cut and paste from an e-mail? I don't mind handing out free advice, but this looks like work you should be doing and I should be paid for. Lots and lots of questions.

you can find many references to roughness here and generally. 46 micron is the "default" value in many analysis. some have measured this at plants, but no one I know has ever specified it as a requirement.

Gas lines benefit from internal coating to lower this, but pigging can break it up

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[BigInch]

Mi'jo tienes q' estudiar alguito por lo menos.

Learn from the mistakes of others. You don't have time to make them all yourself.

 

[EduardoPerez]

I appreciate very much you comments on my questions.-

I have read a lot about this issue but unfortunately there are not a lot of historical records about roughness during shipping & storage in yards and during operation.-

From the forum I detected that you have good experience on this matter and then I decided to get your advise.-

As you correctly mentioned in your answer what I am looking for should be done as a consultory services.

Please, let me know if you can provide them and how we can get in touch.

Best Regards

 

[BigInch]

Unfortunately site rules prohibit advertising and tendering.

you must get smarter than the software you're using.

 

[LittleInch]

I think you are correct in that the historical records of roughness simply don't exist, especially in service, and therefore at least half your questions would be guesses / estimates.

In general long distance gas lines often use internal epoxy type coating spray applied before installation to reduce roughness to a few microns as this has a significant long term effect.

You can't normally use CI in dry gas lines

Internal coating can inhibit use of some pigging activities, but can be overcome.

I've not heard, but have never seriously looked for, any long term studies into roughness before or after pigging. Once a line goes into service the flowrates and pressure then have a base line and operations staff monitor changes from that base line which can be due to a wide number of reasons. If pigging improves things it could be simply dirt in the line as opposed to roughness.

I really think you'll be searching for a long time for many of these answers which have any real back up or data from more than one source.



My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way