4 replies to this topic

[dnrakesh2006]

Hello every body,



I was looking at vendor offer for a two phase separator, MOC what we need was Alloy 825 with NACE compliance (since it is wet service) for vessel internals.

Where as vendor mentioned only Alloy 825 in his offer.

My question is Alloy 825 by default NACE compliance or we need ask vendor specifically for NACE compliance.


Thanks

Edited by dnrakesh2006, 26 February 2013 - 05:49 AM.

[kkala]

I have no experience on NACE requirements, locally being responsibility of Technological (not Process) Dept, apart from news that a carbon steel pipe should be stressed relieved above one limit of H2S content in the fluid, combined with moisture and pH. This note is because there has been no response to the query so far. Hopefully someone really knowing the subject will give a specific answer.

Well, I would require NACE compliance; it does not matter if alloy 825 is totally covered by NACE. It might show some ignorance, that is all.

NACE may require specific grades of alloy 825; or have additional requirements on mechanical properties, granular structure, etc.

Besides NACE may have special requirements on welding the internals to the vessel wall, as they seem to have on alloy 825 gaskets in <http://www.nace.org/...5a-9b6c31db1180>.

[dnrakesh2006]

I have no experience on NACE requirements, locally being responsibility of Technological (not Process) Dept, apart from news that a carbon steel pipe should be stressed relieved above one limit of H2S content in the fluid, combined with moisture and pH. This note is because there has been no response to the query so far. Hopefully someone really knowing the subject will give a specific answer.

Well, I would require NACE compliance; it does not matter if alloy 825 is totally covered by NACE. It might show some ignorance, that is all.

NACE may require specific grades of alloy 825; or have additional requirements on mechanical properties, granular structure, etc.

Besides NACE may have special requirements on welding the internals to the vessel wall, as they seem to have on alloy 825 gaskets in <http://www.nace.org/...5a-9b6c31db1180>.

Thanks Kkala,

 

to be on safer side i asked vedor to comply with NACE.

 

some body told me verbally,  that it is already NACE compliace and hence why are you asking a vendor again to comply with NACE. ( his intenstion was that vendor should not think that we dont know about MOC )

 

still i am scraching my head to find a answer, since we yet to get response from vendor.

[ankur2061]

dnrakesh,

 

Alloy 825 also known as Incoloy 825 with UNS No 08825 is a nickel-based alloy. It is on top of the list of materials resistant to sulfide stress cracking as per NACE MR-0175 / ISO 5156.

 

While ordering you may mention in the purchase order that the material needs to be NACE compliant for the sake of a formal purchase order but you will not need any special test certificates showing testing for NACE compliance which is real expensive to obtain. Instead you can rely on the mill material test certificate to ensure that the alloy composition satisfies the NACE compliance for specific corrosive service where the material is to be used.

 

Hope this helps.

 

Regards,

Ankur

[dnrakesh2006]

dnrakesh,

 

Alloy 825 also known as Incoloy 825 with UNS No 08825 is a nickel-based alloy. It is on top of the list of materials resistant to sulfide stress cracking as per NACE MR-0175 / ISO 5156.

 

While ordering you may mention in the purchase order that the material needs to be NACE compliant for the sake of a formal purchase order but you will not need any special test certificates showing testing for NACE compliance which is real expensive to obtain. Instead you can rely on the mill material test certificate to ensure that the alloy composition satisfies the NACE compliance for specific corrosive service where the material is to be used.

 

Hope this helps.

 

Regards,

Ankur

 

Thanks Ankur this helped me a lot.