Materials & Welding

Martin,   Nice to hear from you after quite a while..I have come across this question in the past while qualifying procedures for duplex S.S, on the strict requirements of oxygen, in purge gas. Please see below the extracts/recommendations of consumable manufacturers, and the general design practices   from API and as well as the technical specification of an oil major. The API recommended practice and duplex/super duplex S.S product manufacturers recommendations is between 2500-5000 ppm of oxygen in the purge gas. Note the general guidelines do not always address the most stringent requirements.   F or  the clients in the oil and gas production industries the  requirement is  typically 50 ppm or below for the (typically offshore applications).. My feel is that, it's difficult to pass the pitting corrosion test (G-48) without such strict control on the level of oxygen. However literatures suggests that a proper purging gas...

Thick carpet material can be pasted on the CS Roller for SS Plate rolling to avoid direct contact of CS. Periodic inspection is required to ensure no damage of carpet during rolling. The same time CS plate cannot be rolled with same carpet for other job which may contaminate with carbon steel.   M.M    From: materials-welding@googlegroups.com [mailto:materials-welding@googlegroups.com] On Behalf Of Ariel Sent: Wednesday, December 28, 2011 11:10 AM To: materials-welding@googlegroups.com Subject: RE: [MW:13346] Stainless steel plate rolling   I would not  be gluing anything to the roller. That would open the door for  possible worse problems such as out of shape rolling.    I would maintain the integrity of the roller and would passivate S/S upon completion of vessel, to ensure that the environment ( C/S workshop fabrication) it has been worked on did not affect/contaminate the material’s anti-corrosive properties . ...

Dear Experts would you please share some information about welding P355NL2? Regards Himan Nikdin -- 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.

Dear Mr. John,   Thanks for your valuable guidance. Please clarify the below   PQR 1 was qualified on 13mm plate and the GTAW deposit was only 5mm with remainder SMAW.   PQR 2 was qualified 22.5mm welded completely with SAW.    Can we make the WPS qualified base metal thickness range of 5mm to 45mm, with maximum SMAW Root deposit thickness of 16 mm and SAW deposit up to the maximum of 45mm.   Regards M.M     From: materials-welding@googlegroups.com [mailto:materials-welding@googlegroups.com] On Behalf Of John Henning Sent: Tuesday, December 27, 2011 10:10 PM To: materials-welding@googlegroups.com Subject: RE: [MW:13335] RE: 13196] combination of PQR with multiple process   This is not as complex as it seems at first glance.  I will address only ASME Section IX – if you need information on how EN/ISO documents handle this issue, I will defer to someone who lives and breathes...

Dear Mr Martin, As we done here SDSS fabrication we are following client Spec, Only up to completion of root pass, Oxygen level shall be below -100 ML/Ml3, During welding if exceed 500 Ml/Ml3 then welding has to stop,this process follow up to three layer. Depending upon you thickness of deposit. After three layer heat input cannot oxidize the root, It optional u can maintain up to 10 mm thick welding ,if pipe thickness is more than 10mm u can stop backing gas . Regards Madhu On 12/28/11, Martin Prad < martin_prad@hotmail.com > wrote: > > Hi friends, > > I have 2 different specification which the requirements are different for > the oxygen level in purging gas during the welding of super duplex pipe. > > One of them calls for 25 ppm (0.0025%) another one calls for 5000 ppm > (0.5%). Could you please shed some light on this as which one is up to the > standard with references? > > Thanks, > Martin. > > -- ...

No. Over pressurising may lead to failure. In case of absolute necessity check with designer. Gopal Sent from BlackBerry® on Airtel From: Kanagarajan G <g.kanagarajan@gmail.com> Sender: materials-welding@googlegroups.com Date: Wed, 28 Dec 2011 11:08:39 +0400 To: <materials-welding@googlegroups.com> ReplyTo: materials-welding@googlegroups.com Subject: [MW:13346] Hydro test for different pressure Hi,   Shall we carryout two different hydro pressure packs together in one hydro test for the maximum one.   For example, One test pack 30 PSI and another test pack 200 PSI.(Material same)   Regards,   Kanagarajan.G   -- 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 education...

Hi Vino   Combining of two codes are not regular practice, however, the owner, depends upon the service criteria may select combination of Codes or his specifications if he wishes.   However, when there is a Code stamping requirement like U-stamp, the complete design, construction, inspection and testing shall meet the minimum requirements of respective Codes. There are many client, who provides amendments to the Codes are more restrictive than Codes.   In this case, the selection of Sec VIII may not be appropriate since, the item mixer is exempted from Sec VIII and due to design input / output (piping stress analysis, thermal expansion/contraction, pipe supports are different from Sec VIII). Refer to my email below as stated earlier.   But as per Codes perspective, No Code allows the use of multiple Code for the single construction unless it is stated so, however the Client is always BOSS. If there is any conflict, it is better to resolve it in advance. ...