Pump material selection

[Sabergg1981]

Hi all. We have a flare knock-out drum centrifugal pump in an arrangement of 1+1, and hydrocarbon with 80000ppm h2s and 150000ppm chloride. Our design temperature is -100c . What class do you suggest?
Thanks

 

[LittleInch]

See the replies in the pumps forum first. We suggested he post it in the materials section.

Is design temp minus 100C? What is max design temp, what is operatiing temp? This seems very low for a flare KO drum. Is there any water? what is the fluid? Is there any oxygen in the water or liquid? Super duplex is my answer without knowing the answers to the questions above

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[Sabergg1981]

Dear little inch
Thanks from your concern. Our design temperature are 100 & minus 100 and operating temp is about 60. This very low temperature is caused by deperessurizing of flare. This 1+1 pump is hired to discharge water content of hydrocarbon to closed drain system. We dont have oxygen in our gas composition. But h2s and wet chloride as mentioned above.

 

[StoneCold]

Sabergg1981
I would buy a 316ss pump and have the internals coated with Tantalene.
Short of that I might consider a stainless pump with an internal coating, maybe something from Belzona.

Regards
StoneCold

 

[TVP]

Tantaline is the name of the tantalum-based metallurgical surface treatment:

http://www.tantaline.com/Pumps-93.aspx

What sort of life expectancy is required for this application?

 

[Sabergg1981]

@ TVP

25 years

 

[SJones]

Are you using NACE MR0103 or ISO 15156 for the H2S service, and what is the design pressure of the knock out drum to which the pump is attached? I'm guessing that pumping water at -100 deg C is the subject of another thread.


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.

 

[TVP]

I'm not sure about superduplex for this application. I would investigate something like Tantaline surface treatment of 316.

 

[SJones]

Superduplex won't go to -100 deg C, and you don't know the H2S partial pressure to make a call. It's yet another case of not working the design temperatures properly in order to rationalise materials selection: bang! it's -100 deg C; bang! it's an expensive alloy then. At an operating temperature of 60 deg C, it will be a very close call to allow treated 316 with that chloride content in H2S service. With the very limited information that the originator has put forward,they are staring at a nickel alloy in the first instance.

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.

 

[Sabergg1981]

What's specification of tantaline?