Piping Welding - Edge preparation and application of backing ring 1

[AlfaMike5886]

Hi everyone,

while welding pipes, which kind of edge preparation should be considered? single V or double V, J type or U type? what are the basis and criteria to decide which type of edge preparation should be done?

Also, when should we use backing ring and when should not? which type of backing rings should be used? what is criteria for selection?

 

[LittleInch]

Alfamike,

These are pretty basic questions that you really need to ask your welding engineer. ET is good at answering specific questions but assumes a certain level of knowledge which it doesn't look like you have.

And also there is a dedicated welding forum under structural engineering but it covers all welding.

Probably better to delete these posts and just ask in there or search for a general guide or text book. The AWS may have some guides on their website.

Also look at this set of links in that forum

https://www.eng-tips.com/links.cfm?pid=725

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[AlfaMike5886]

Dear LittleInch,
if you do not know the answer please say "I do not know" or please do not answer at all.
let those who know the answer reply. dont give obvious answer.

i do not have knowledge thats why i am asking. or else why would i waste my time typing questions of which i already know answer.

 

[weldstan]

Too many variables. They include welding processes, alloys, thickness, ID accessibility, shop or field welding, NDE requirements, costs, contract specification requirements, etc.

 

[AlfaMike5886]

Thank you weldstan,

could you please guide me to relevant reading material/code or standard clauses, where i can find rules/criteria/method to determine type of edge preparation.? and when to select backing ring?

 

[Rputvin]

could you please guide me to relevant reading material/code or standard clauses, where i can find rules/criteria/method to determine type of edge preparation.? and when to select backing ring?

If I might suggest - AWS offers a number of SWPS, Standard Weld Procedure Specifications, that are available for purchase. You should be able to find one that is suitable for your use case, or very close to it. Even if you don't intend on using the SWPS and will still write your own, it gives you a very good understanding of what a complete WPS entails, and it will come complete with specified materials, specified form and size limits for the materials and welds, allowable joint geometry and design, acceptable filler rod, allowable weld forms, etc.

This does not give you the answers you need, but it can help fill in a lot of the gaps when trying to wrap your head around ASME Section IX for the first time.

If you're trying to jump into the world of code welding without already having been a piping/quality/weld/pressure vessel engineer or something of that nature it's going to be a LOT of information to absorb, and may be a much larger undertaking than you might have thought.

Or not, we really don't know since all we have is a few sentences and some very open-ended questions that make it apparent you need more help than a forum can provide for you. I started with an intro course from Hartford Steam Boiler on ASME VIII and IX that really helped ground some of the terms and methods in BPVC, I'd suggest something similar before you get too far down the road and realize you're in deeper than you think.

 

[weldstan]

AWS Welding Handbooks, ASM Handbook Welding Volume. I had a Pipe Welding Handbook but after 6 years of retirement gave it to the local JC welding staff and I forget the author.