Asphalt or 3LPE to Coat Undersea Steel Pipes?

Please expand on PE. Does PE means Poly Ethylene. If yes than I would like to know how you are installing the PE coating?

Also please advise the pipe size and fluid that pipe is seeing.

Daniel

Thank you for your reply. my reply to your comments are as follow:

- Yes 3LPE means three layers system Polyethylene, this system composed of three functional components and consist of a high performance fusion bonded epoxy(FBE)followed by a copolymer adhesive and an outer layer of polyethylene

- Installing the coating at pipes coating manufactory, and the Process for pipes are (preheat, blast clean, grind surface defects, surface inspection, final surface treatment,induction heat,FBE application, extruded copolymer and extruded polyethylene.)

- Pipe size is (8 inches) using to transport petroleum products(Mogas and Gasoil).

Best regards

New one

Dear New one,

how do you intend to make repairs and joint connections? to my expeerience, it is much easiyer to do it with Asphalt than PE (repairs & joints) in the field when welding the pipes.

DM

In what part of the world are you laying the Pipeline?

Is Asphalt Environmentally Permissible and Sound in your Location?

I have no experience on 3LPE so can not comment. Buit I do have long and very satisfactory experience with : gunite . Some of the sub-marine fuel pipes I laid as a young Engineer are still used commercially (more than fourty years ago).

Because most of these pipe-lines are subjected to "pigging" ( i.e. with internal air pressure entrained cleaning piston that clears the line for different fuels )these underwater lines are subjected to some vibration from that. As well some of these pipelines have been laid in earthquake areas where 6.5 or higher tremors are common. To my mind these factors militate towards very carefully executed "gunite" . Let us know how you do it finally.

Labor Omnia Vincit.

Similar CR4 thread at:

http://cr4.globalspec.com/thread/12661/FBE-against-3LPE?frmtrk=CR4digest

My response follows same: Number1) we learned decades ago that asphalt, although suitable for irrigation-type lines on land, gets eaten-through by Toredo worms in the offshore environment (the buggers to whom Columbus once lost a ship). Coal tar enamels and coal tar epoxies replaced asphalt, eventually being replaced by Fusion Bonded Epoxies due to environmental concerns.

3LPE has a notorious reputation for developing delaminations, and the shielding effect that it has on CP current leads to corrosion issues at those failures. FBE ... with or without cement weight-coating, depending on size and usage of the P/L ... has proven itself so superior, I would be surprised to hear of anyone choosing otherwise. That is, unless the nearest plant for applying FBE is "a world away". As another asked; where is this P/L...?

Thanks a lot for every one made comments on my question.

New One