H2S service/EN 1

[2ndchild]

hi,
what is the European standard which covers the H2S service?
(NACE MR0175 equivalent!)
and what is the added thickness in H2S service (corrosion) for carbon and stainless steel piping ?
(according to EN ISO 15156 or an other Euro standard)
best regards.
Leyla

 

[SJones]

As far as I am aware, there is no European equivalent to ISO 15156. Regarding corrosion allowance see

http://www.eng-tips.com/viewthread.cfm?qid=130588

Normally, one would not consider a corrosion allowance necessary on a properly selected corrosion resistant alloy.

Steve Jones
Materials & Corrosion Engineer

http://www.pdo.co.om/pdo/

 

[2ndchild]

hi,
when we use a carbone steel pipe in H2S service, the manufacturer must consider at least 10% of material available for corrosion. with regard to European standard, the corrosion allowance exists but I don t know how I can evaluate it?
thanks,

Leyla

 

[Carburize]

This is a little bit outside my usual field but I don't believe that "corrosion allowances" are part of H2S resistant material design philosophy since metal loss it not the real problem but embrittlement. Perhaps some of the corrosion specialists could comment?

 

[SJones]

The thread I gave you does indicate how to evaluate corrosion allowance but it is something that is too complex to deal with in this forum context. For carbon steel, you first need to have an estimate of the expected corrosion rates resulting from the fluid flow. In H2S containing systems this is not as straightforward as for solely CO2 containing systems as. Other factors also come into play such as design life, use of inhibitors and, not least, the consequences of an uncontrolled fluid release. You could adopt a "standard" corrosion allowance of 1 mm, 3 mm, or 6 mm but a) will it be enough; or b) will it be an excessive cost? You see - not a simple subject!

Steve Jones
Materials & Corrosion Engineer

http://www.pdo.co.om/pdo/

 

[choib]

Hi
Would you explain to me the procedure to calibrate the IR drop test station,during the commissioning of the pipeline CP system.

Best regards

 

[TomEun]

Please find the following standard;

EEMUA (The engineering Equipment and Materials Users Association) Publ. 179; 1996 – A Working Guide for Carbon Steel Equipment in Wet H2S Service (developed largely from oil refinery experience)

Thomas Eun
Materials and Corrosion Engineer