Skip to main content

[MW:27273]

By Materials & Welding
Dear Experts can you advise me for the below clarifications (also refer the attached sketch):


Shell to bottom cutting for Tank bottom plate replacement as per API-653

As per API 653 section 9.10.3, it is recommended for removing existing tank bottom by cutting the shell parallel to tank bottom at a minimum of ½'' above the bottom to shell weld.

For shell plate having a thickness of 10mm, a minimum of 10mm height will be reduced from the existing shell height (if removal of heat affected zone is not considered) 

Alignment with existing piping connections can be made possible by increasing the eathen foundation level for 10mm, prior to laying of new bottom/ annular plate.

Still is a concern of decrease in minimum distance from bottom of Tank to centre of shell/ manhole Nozzles and reinforcement pads. After completion of repair/ replacement works, Tank needs to be certified for API 653.

Also would like to know any impact of above by use of gas cutting method for the above (pug cutting machine)


Thanks in advance
--
SANDEEP K SREEDHAR

--
https://materials-welding.blogspot.com/
https://www.linkedin.com/groups/122787
---
You received this message because you are subscribed to the Google Groups "Materials & Welding" group.
To unsubscribe from this group and stop receiving emails from it, send an email to materials-welding+unsubscribe@googlegroups.com.
Visit this group at https://groups.google.com/group/materials-welding.
For more options, visit https://groups.google.com/d/optout.

Comments

Post a Comment

Popular posts from this blog

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

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

The Schaeffler and Delong diagrams for predicting ferrite levels in austenitic stainless steel welds

By Materials & Welding
Introduction Ferrite is important in avoiding hot cracking in during cooling from welding of austenitic stainless steels. 'Constitution diagrams' are used to predict ferrite levels from the composition by comparing the effects of austenite and ferrite stabilising elements. The Schaeffler and Delong diagrams are the original methods of predicting the phase balances in austenitic stainless steel welds. Nickel and chromium equivalents A 'nickel equivalent' is calculated for the austenite stabilising elements and a 'chromium equivalent' ferrite stabilising elements. These are used as the axes for the diagrams, which show the compositional equivalent areas where the phases austenite, ferrite, martensite (and mixtures of these) should be present. Although intended to show the phase balance of weld fillers, these diagrams can also be used to illustrate the phase balance of the 'parent' material. There are different diagrams for dif...
Post a Comment
Read more