pipeline FJC options 1

[longhu]

Hi experts, this is my first post here.
My previous experiences are limited only for onshore pipelines and always utilize HSS for FJC.
We are currently doing FEED for offshore pipeline and I have below options to select from client specifications for offshore pipeline FJC.
I have done some preliminary research, but still hard to choose the most fit-for-purpose one (integrity, cost, ease of application), hope you experts can give more input from field experiences.

1. Non-crystalline low viscosity polyolefin tapes with polymeric tape outer wrap
This looks easy to apply and doesn't require heating, but I don't know if tape wrapping will give high integrity in subsea

2. Liquid epoxy or derivatives
This also looks easy to apply, but long curing time may disturb whole pipelaying process.

3. Liquid polyurethanes per derivatives
Similar issue with liquid epoxy

4. Flame sprayed polyethylene powder applied over an epoxy layer
Good high integrity FJC, but likely tough to be applied offshore as this require specialized machinery to heat and spray

5. Polyethylene tapes/sheets hot applied over an epoxy primer
Similar issue with polymeric tape wrap, and require additional heating equipment

 

[SJones]

1. What is the linepipe factory coating - that will help whittle the options down compatibility wise?
2. What is the pipeline maximum operating temperature, and have you found any coating systems with an ISO 21809-3 qualification that fit the factory coating type and the temperature?
3. Have you actually looked at the curing times of the liquid epoxies and polyurethanes accounting for an elevated substrate temperature. Here are some typical coatings, download the datasheets and check out cure times: SPC SP-2888 RG, Canusa HBE
4. Keep the perceived "difficult" options on the table, provided that they are compatible and qualified, and then thrash them out with the pipeline installation contractors when holding tender clarifications

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/in/drstevejones

All answers are personal opinions only and are in no way connected with any employer.

 

[BenMacier]

Forget option 1 it will not pass the stinger.
Options 2 and 3 are low corrosion resistant and will require higher cathodic protection demand (more sacrificial anode quantity), so avoid.
Options 3 and 4 are widely used and rely on semi-automatic equipment, a bit like the welding station on board.
If you can make double joints on board or onshore, this will balance the laying rate: slowest FJC station but more pipe length laid off.

 

[LittleInch]

What's wrong with HSS?

Pretty common approach.

Tape I've never seen offshore. Others depend on curing time and ability to grit blast.

So much offshore is dependant on the particular vessel and their normal way of doing it.

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

 

[longhu]

thanks for the answers! great for consideration.

sorry, forgot to give more details, newbie mistake

1. What is the linepipe factory coating - that will help whittle the options down compatibility wise?
3LPE

2. What is the pipeline maximum operating temperature, and have you found any coating systems with an ISO 21809-3 qualification that fit the factory coating type and the temperature?
75 C

3. Have you actually looked at the curing times of the liquid epoxies and polyurethanes accounting for an elevated substrate temperature. Here are some typical coatings, download the datasheets and check out cure times: SPC SP-2888 RG, Canusa HBE
ah, thanks, we were concerned about handling cure time, which there are not many information out there. canusa HBE looks promising.

4. Keep the perceived "difficult" options on the table, provided that they are compatible and qualified, and then thrash them out with the pipeline installation contractors when holding tender clarifications
noted

Forget option 1 it will not pass the stinger.
sorry, forgot to info that there will be concrete, so stinger is no problem.

What's wrong with HSS?
nothing wrong, just not in client approved type

So much offshore is dependant on the particular vessel and their normal way of doing it.
correct, this is that I have no experience of, so the simplest options, the better

 

[SJones]

@longhu - you didn’t mention anything about having examined ISO 21809-3 and its qualification requirements

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/in/drstevejones

All answers are personal opinions only and are in no way connected with any employer.

 

[BenMacier]

Well if these pipes are CWC (concrete weight coated) you either need to fill up the FJC to match the CWC thickness or taper the CWC ends, otherwise there will be a lot of damages.
So if you go with the fill-up option, it's another challenge all together!

* Finding a solution is great * Knowing how to implement it is fantastic * Believing it is the only one and best is naive ?