NACE standards for a pump

[rachba]

I have a water pump with 160ppm of H2s and around 200000ppm of chloride. The pump is in duplex.
Is this compatible with the NACE requirement

 

[SJones]

"The NACE requirement" works with partial pressure of H2S in the gas phase. Start with deriving that value.

Steve Jones
Corrosion Management Consultant

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

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

 

[EdStainless]

20% Chloride, maybe a super duplex, though I would be looking at Ni alloys.
Is there any oxygen or CO2 in the fluid?

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P.E. Metallurgy, Plymouth Tube

 

[rachba]

I found the NACE requirment MR0175 and yes it work with the partial pressure of H2S (for 160ppm of H2S it's ok with the NACE requirment)
but i didn't find something for the chloride

 

[SJones]

How did you calculate the partial pressure of H2S in a water system? There is no chloride restriction when a maximum H2S partial pressure criterion is applied.

Steve Jones
Corrosion Management Consultant

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

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

 

[rachba]

I have 160ppm of H2S so if we suppose a ideal gas 160ppm -> 0.00016 volume fraction -> 0.00016 molar fraction --> 0.00016*100= 0.016%mole
i have the total pressure so the partial pressure= Pt*%mole
is it right?

Tanks

 

[EdStainless]

What is the max system pressure? That is what you multiply the vol fraction by.

The NACE spec doesn't refer to Cl levels, but if you want the equipment to last more than a few months you had better pay attention to it.

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P.E. Metallurgy, Plymouth Tube

 

[SJones]

160 ppm suggests dissolved H2S in the liquid. Look at Part 2, Annex C, C.2 and see if that provides any further assistance.

Steve Jones
Corrosion Management Consultant

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

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

 

[rachba]

the Max system pressure is 20bar (290psi) --> partial pressure (psi)= 290*0.016/100=0.0464psi and if i refer to the Part3; A-7-2 table A.24 for duplex stainless steels Max partial pressure of H2S is 1.5 psi ---> so my pump in duplex is responding to the NACE requirement

I hope this is right and i'm really greatful you helped me alot both of you!!

Thank you !!