Sea Water Intake Lines

[BilalAdi]

hi all, i'm mechanical engineer at bp operation in tangguh LNG, papua. i wanna ask a question about sea water intake line material, is it safe if we are using the GRE pipe,or I should use a super duplex material, and does anybody has an information about the price of super duplex material, thx

Bilal Adi Akbar
Mechanical Engineering Challenger
BP Tangguh Operation

 

[SJones]

Size, diameter, design pressure, design temperature, buried, submerged, criticality, impact risk, etc etc? Your first reference point might be ETP GP 36-10.

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04

 

[EdStainless]

I would look at options such as precast concrete and cement lined steel before I looked at super duplex. The cost would be huge.
What diameter, length and pressure are you dealing with?

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Plymouth Tube

 

[BilalAdi]

the diameters are 12" and 10" the operating pressure is 25 kg/cm2 and the existing line is using CS cement lined, after 2 years operation there were some leakages at the pipe fittings, it was suspected due to cement bonding quality.the pipe length is about 10 m long, and it's the discharge line of the sea water pump

Bilal Adi Akbar
Mechanical Engineering Challenger
BP Tangguh Operation

 

[strider6]

if the pipe length is 10 m i'll go for a corrosion resistant alloy like SuperDuplex..

see this paper, maybe it can help:

http://www.copperinfo.co.uk/alloys/...s/pub-38-materials-for-seawater-pipelines.pdf

S

Corrosion & Rust Prevention Control

 

[SJones]

But you need to know the seawater temperature before diving into super duplex!

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04

 

[BilalAdi]

ooo yes,sorry i forgot, the temperature of the sea water is about 30 celcius

Bilal Adi Akbar
Mechanical Engineering Challenger
BP Tangguh Operation

 

[strider6]

SJones

In my experience 30°C is the limit for the application of Superduplex (PREN >40) in seawater.

S

Corrosion Control

 

[SJones]

Indeed. You had a lucky guess then!

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04

 

[BilalAdi]

well, after i read in many literature, especially in ETP GP,i have decided to change it with super duplex,now does anybody has the info about the price of super duplex S32760?thx before

Bilal Adi Akbar
Mechanical Engineering Challenger
BP Tangguh Operation

 

[strider6]

Steve

It was not a lucky guess but just a simple suggestion based on the assumption that if the service is a Sea Water Intake Lines then the operating temperature should be quite "low"...
and as i said it was just a suggestion not a material selection report..

have a nice and lucky day

S


Corrosion Control

 

[SJones]

Vitt,

My point was: a recommendation without knowing the service conditions is a lucky shot. Tangguh is in tropical waters and will be very close to the generally adopted limit for super duplex. In all probability, the seawater may, on occasion, exceed 30 deg C.

Best to get complete data before making firm recommendations.

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04

 

[strider6]

Steve,

Experience is something that is not possible to teach.. You're right, i didn't think that in some areas of the world the seawater temperature can reach that values...

thanks for your help

all the best

Vitt





Corrosion Control