Skip to main content

Re: [MW:5087] Weld proximity in pressure vessels

By Materials & Welding
There are no codes (except for one in Australia or New Zealand I heard about) that state any "mandatory" limitations. There is only good construction practice, usually some companies will state welds must be 1-1/2  times the OD of the pipe apart etc., some may state twice the diameter.   But there are no code stipulations. These are only good construction practice.
 
If you are stuck, you can weld side by side, this of course is not favorable. Bottom line is if the weld has to be close, you can do it.
 
Hope this helps, Bob
----- Original Message -----
Sent: Thursday, May 06, 2010 12:45 AM
Subject: [MW:5081] Weld proximity in pressure vessels

Dear All,

Can you please confirm if there are any mandatory limitations on weld to weld distance (nozzle to CS/ LS, welds of attachments to other welds etc.)

Details:

  1. Governing code: ASME Sec VIII Dev 1
  2. PWHT – Applicable
  3. NDT: 100% RT & MPI on attachment/ fillet welds
  4. Service – Sour

 

Does a weld meeting all above criteria (2 to 4) have an issue, metallurgically, when welds are too close or don't have even spacing e.g. reinforcement pad to demister support ring etc.

 

With Regards,

V.Vaidyanathan

 


*** WORLEYPARSONS GROUP NOTICE *** "This email is confidential. If you are not the intended recipient, you must not disclose or use the information contained in it. If you have received this email in error, please notify us immediately by return email and delete the email and any attachments. Any personal views or opinions expressed by the writer may not necessarily reflect the views or opinions of any company in the WorleyParsons Group of Companies."

--
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.

Comments

Post a Comment

Popular posts from this blog

Re: [MW:34105] SA266 GR4N 4 Cycle SPWHT

By Materials & Welding
Hi,  You are correct, Minimum refers to the one cycle for which this part will expose until final work shop PWHT. hence mill test certificate shall include this.  Max. SPWHT, refers to additional cycles of heat treatment that are reserved for future repairs during equipment lifetime.  Again, these simulated no. Of cycles shall be specified in MTC.  The idea is we need to make sure that steel mechanical properties are not compromised upon exposure to multiple repairs (i e 4 cycles in your case).  One could say, if steel is subjected to 4 cycles and is ok, then it should by defacto be good for one cycle, yet, this is wrong assumption cause mechanical problems and microstructure of materials varies accordingly based on no. Of cycles for which material will expose. This is apparent in alloy steel and especially for impact test values as an example.  In your case, this forged CS with properties before PWHT can be understood to be " as forged" condition (i.e. Wit...
Post a Comment
Read more

Materails FAQs

By Materials & Welding
Q: What are equivalents for standard Q 235 B (and Q 235 A) for U-channels? (asked by: boris.vielhaber@vait.com) A: DIN Nr. = 2393 T.2, 2394 T.2, EN 10025 W. Nr. DIN 17007 = 1.0038 Design DIN 17006 = RSt 37-2, S235JRG2 (Fe 360 B) Q: What is St DIN 2391 BK material? (asked by: dmcandrews@automaticstamp.com) A: Precision steel tubes, cold-finished/hard. Q: What is C.D.W. Boiler Tube? (asked by: montydude123@yahoo.com) A: Cold Drawn Welded Boiler Tube. Q: WHAT IS W.Nr. 1.4301? PLS TELL US IN EASY LANGUAGUE (asked...
21 comments
Read more

Heat tint (temper) colours on stainless steel surfaces heated in air // Heat tint

By Materials & Welding
Introduction The colour formed when stainless steel is heated, either in a furnace application or in the heat affected zone of welds, is dependent on several factors that are related to the oxidation resistance of the steel. The heat tint or temper colour formed is caused by the progressive thickening of the surface oxide layer and so, as temperature is increased, the colours change.   Oxidation resistance of stainless steels However, there are several factors that affect the degree of colour change and so there is no a single table of colour and temperature that represents all cases. The colours formed can only be used as an indication of the temperature to which the steel has been heated. Factors affecting the heat tint colours formed Steel composition The chromium content is the most important single factor affecting oxidation resistance. The higher the chromium, the more heat resistant the steel and so the development of the heat tint colou...
Post a Comment
Read more