Sea Water Material selection-Valve

[peter vaf]

What is the best Material selection for the valve trim using in Sea Water process Line.

Duplex Stainless Steel
Super Duplex Stainless Steel*
Nickel Aluminium bronze

Cl pmm:2000
Temp :below 60

 

[LittleInch]

Aluminium bronze is more common.

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

 

[LittleInch]

Just get the whole valve made out of it, not "trim"

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

 

[TugboatEng]

Best? Monel. A bronze body with monel trim will net you the best life provide you are not using sodium hypochlorite injection and the salt water isn't heavily contaminated with sulfides.

Good news is that this combination is maintained as an on the shelf package as it is specified by MIL standards. This keeps the price more reasonable.

 

[EdStainless]

I'll second TBE's recommendation.
The NAB will be fairly erosion resistant, fouling resistant, and plenty corrosion resistant. The Monel trim will last nearly forever.
And as he says, as long as you are not chlorinating right before the valve and do not have sulfides/H2S issues it will be fine.

If this were heavily chlorinated or contaminated and high pressure or flow, I would lean to super duplex. But your QA would need to be very good to assure that you got a good valve.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed

 

[SJones]

Below 60 - how far below and what units?

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.

 

[peter vaf]

60 Celsius
5~60 Celsius

 

[MJCronin]

Best ?.....

Pete, does "best" mean cheapest ?

Does "best" mean available quickly ?

How big is this beast ? ........ Like most internet/eng-tips newbies you give a minimum of information

(.... and you never seem to use the terms "please" or "thank you")

Pete, when you use the term "Sea Water" ..... you can mean very many things ..

Are you talking about the corrosive liquid horror commonly called the Dead Sea or the mild and pristine Baltic Sea (which can sometimes substitute as a clear and refreshing dinner drink) ?

Pete ?

Are you still with us ?

MJCronin
Sr. Process Engineer

 

[peter vaf]

Dear MJCronin,

Thank you for your advice and support.

Concerning to mentioned subject,I understand ,My question about the material selection is general.and may be my mistake to be raised here with such a incomplete information's.

Of course ,For the Evaluation of Correct Material Selection in details ,It needed ,fully project specification/PMS/P&ID to be sent ,which may out of scope of responsiveness here.

Thank you again for supporting

 

[LittleInch]

Pete.

I'd missed the 2000 ppm CL bit. That's still OK to spread on fields so not really "sea water".

Also what is oxygen content?
If you get it down to ppb then you can use carbon steel...

60C is quite warm though

As MJC says, first define "best"
Price?
Availability?
Reliability?
Long life?



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

 

[peter vaf]

Dear LittleInch

Thank you for your reply .

According to "BP ENGINEERING TECHNICAL PRACTICES"

Guidance on Practice for Valves GP 62-01(BP GROUP)

Typical application of metallic trim materials is as below :

1)Duplex Stainless Steel (22% Cr.)===>Corrosive hydrocarbon service.
2)Super Duplex Stainless Steel (25% Cr.)====>Sea water service, very corrosive hydrocarbon service. Extreme sour service.
3)Nickel Aluminium Bronze===>Sea water, black sewage, brine, fire water. Good for high velocities. Unsuitable for sulfide polluted water.

Regarding to cost ,of course "Nickel Aluminium Bronze" cost is about 20%~25% more than "Duplex Stainless Steel (22% Cr.)"

 

[LittleInch]

So which do you think is "best"?

You have water which is not seawater.

True warm aerated sea water will eat most metals, even duplex.

But your stuff stainless would probably be OK.

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

 

[peter vaf]

Dear LittleInch,

The valve location is after sea water intake line(upstream) and before Mixer tank inlet(Downstream).

 

[LittleInch]

Then it's not 2000 ppm Cl.

And not sure what 60C comes from.

Getting your fluid details correct is vital.

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

 

[SJones]

Forget GP 62-01, it’s GP 36-15 that you need.

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.

 

[peter vaf]

really appreciate