What is the material difference for sour and sweet service?

[larryli2004]

I am just wondering that what is the difference between sour service material and sweet service material. I know sweet service material cannot handle sour gas or emulsion. Then how is the sour service material? I think they are ok with sweet service? Is that right? Can somebody clarify for me? Thanks.

 

[JLSeagull]

Consider hardness. Obtain the latest NACE standard pertaining to sulfide stress cracking such as MR0301, Materials Resistant to Sulfide Stress Cracking in Corrosive Petroleum Refining Environments; or TM0177 Laboratory Testing of Metals for Resistance to Sulfide Stress Cracking and Stress Corrosion Cracking in H2S Environments. I would have mentioned MR0175 but it appears to be obsolete.

 

[JLSeagull]

I lied. MR0175 / ISO 15156 15 Dec 2003 is current and active.

 

[larryli2004]

Thanks,JL, I will check MR0175. However, I am still wondering when we order those pipes, what is the material difference? For outside pipe, normally I use A333 Gr. 6, also mention it is for sour low temp, if only for low temp, is there difference for material wise?

 

[Ashereng]

JL,

Are you thinkin of NACE MR-0103?

This came out after MR-0175, and is primarily for refineries.

Larry,

Yes, you can use "sour" material in sweet service. Most instruments and valves carry NACE certification, regardless of the service we put them in. This way, you don't make a mistake, or run out of "sour" valves.

"Do not worry about your problems with mathematics, I assure you mine are far greater."
Albert Einstein
Have you read FAQ731-376 to make the best use of Eng-Tips Forums?

 

[JLSeagull]

Yup,
MR0103-2005.