[MW:4216] pickling& passivation after hydrotest is ideal?

 

Hello Hrishi,

 

Pickling and passivation usually improves the corrosion resistance of stainless steels, lost due to fabrication. Since your client has requirements of pickling and passivation prior to hydrotest please follow ASTM- A-380 guidelines – “Standard Practice for Cleaning, Descaling, and Passivation of Stainless Steel Parts, Equipment, and Systems” for the same.

 

Pickling solutions are quite aggressive as they contain aggressive acids and may damage the components if proper cares are not exercised. Picking is done with HNO₃ +HF  mixture, while passivation is to be done with  diluted HNO₃ . ASTM-A380 lays out the detailed procedure, precautions to be taken while pickling ansd passivation.

 

Thanks

 

Pradip Goswami,P.Eng

Senior Engineer/Specialist(Welding-Metallurgy)

Engineering & Training Services Division

ONTARIO POWER GENERATION Inc.

PO Box-2000, RR-55(South)

Nanticoke, Ontario,N0A1L0

Tel:-(519) 587-2201, Ext 3107--in Nanticoke

         (416) 231-4111, Ext 5925--in Kipling,Toronto

Fax: (519) 587-6814

Email-pradip.goswami@opg.com.

 

-----Original Message-----
From: pgoswami@sympatico.ca [mailto:pgoswami@sympatico.ca]
Sent: Thursday, February 04, 2010 12:44 PM
To: GOSWAMI Pradip -THERMAL
Subject: FW: [MW:4209] pickling & passivation after hydro test is ideal?

 

 

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Date: Thu, 4 Feb 2010 15:07:01 +0530
Subject: Re: [MW:4209] pickling & passivation after hydrotest is ideal?
From: hrishikm07@gmail.com
To: materials-welding@googlegroups.com

Dear Gopu

 

Sorry I couldn't convey my requirement fully..

 

The vessel does have picking and passivation requirement as per project specification apart from PWHT and external blasting & painting requirement.

 

Hrishi

 

On Thu, Feb 4, 2010 at 2:42 PM, GOPU NAIR <gopunair5343@yahoo.com> wrote:

 

Dear Hrishi From your query it is understood that customer wants blasting and painting of external surface only and does not require internal pickling and passivation. Do not carry out pickling and passivation unless it is a customer specification requirement. Pickling and passivation can do harm unless thorough flushing is done which could be difficult in a closed vessel.   Gopu --- On Thu, 4/2/10, K.M Hrishikesan <hrishikm07@gmail.com> wrote: From: K.M Hrishikesan <hrishikm07@gmail.com> Subject: [MW:4204] packling&passivation after hydrotest is ideal? To: materials-welding@googlegroups.com Date: Thursday, 4 February, 2010, 10:14 AM Friends   I have a vessel with MOC SA 387 11 cl-1class11 with  410S cladding (Coke drum). The vessel is to undergo PWHT and external blasting and painting. Please suggest if I go for pickling & passivation after hydrotest that will be more appropriate? In my earlier projects I have done picking&passivation before hydrotest. What is the best practice? Please advise.   Regards Hrishi -- To post to this group, send email to materials-welding@googlegroups.com To unsubscribe from this group, send email to materials-welding-unsubscribe@googlegroups.com For more options, visit this group's bolg at http://materials-welding.blogspot.com/ The views expressed/exchnaged in this group are members personel views and meant for educational purposes only, Users must take their own decisions w.r.t. applicable code/standard/contract documents.

 

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The views expressed/exchnaged in this group are members personel views and meant for educational purposes only, Users must take their own decisions w.r.t. applicable code/standard/contract documents.

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To post to this group, send email to materials-welding@googlegroups.com
To unsubscribe from this group, send email to materials-welding-unsubscribe@googlegroups.com
For more options, visit this group's bolg at http://materials-welding.blogspot.com/
The views expressed/exchnaged in this group are members personel views and meant for educational purposes only, Users must take their own decisions w.r.t. applicable code/standard/contract documents.

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