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Up Topic Welding Industry / Inspection & Qualification / Welding Inspection Maximum Reinforcement
- - By DannyAgudelo (*) Date 04-06-2018 02:29
im a welder trying to gain some more technical expertise. I've been studying code parameter and so on and recently came across to a table that explains the maximum reinforcement allowed on a weld. The table includes some values. My question is the maximum reinforcement allowed seems to change depending on the "design temperature". Whats is this design temperature? Is it the temperature the weld is going to be exposed to?
This can be found on this pdf on page 14, table 5.
Thank you
Parent - By Lawrence (*****) Date 04-06-2018 11:29
Hi Danny.

The table you are viewing is taken from the AWS "Book of Specifications" used for the CWI exam.

This is not an actual working specification.  It is a simulated code/specification and the section you are viewing is dedicated to pressure piping.

The book of specifications (BOS) has several different codes within it... (Structural, Piping, Pressure vessels) and they are to be used with mock-up weld samples and mock-up welding procedures and PQRs by test takers to prove they can navigate numerous codes that have differing acceptance criteria.

The table you are viewing in essence is not a real table... However it might closely resemble API 1104  piping specification.

As to your question about design temperature... I think you are probably right to assume that the temperatures they are noting are what the weldment would see in-service.
- - By 803056 (*****) Date 04-07-2018 03:32
As Lawrence said, the table is from the Book of Specifications used for the Part C CWI examination. The table is modeled after ASME B31.1 Power Piping Code. The B31.1 Power Piping Code covers the type of piping typically found in a power house. Think steam lines if you will. Steam pressure goes up as the operating temperature increases. Think of a pressure cooker. The water boils at 212 degrees F at sea level. As the temperature in the pressure cooker increases, the internal pressure increases as well.

In the case of power piping, the same principles apply. The concern is that the greater the weld reinforcement, the more notch-like the toe of the weld becomes. It becomes a severe notch-like stress riser if the height (reentrant angle) is not controlled.

The maximum design pressure is the pressure used when the designer is calculating the wall thickness of the pressure vessel or the piping system. The maximum design temperature of steam dictates (for all practical purposes) what the design pressure is. Again, B31.1 is primarily the design/fabrication/welding/inspection criteria for steam lines in a power house.

Parent - - By welderbrent (*****) Date 04-07-2018 14:33
Hey Al (said in the lowest possible whispering voice),

Didn't you mean Part 'B' on the CWI exams??  Not Part 'C' (Codebook).

BB  SSSHHHH, don't tell anyone that Al made a typing error, we know it wasn't because he didn't know that.
Parent - - By 803056 (*****) Date 04-07-2018 15:25
"I'm alright," I shout as I stand up and brush myself off. "I just wanted to see if anyone was paying attention!"

I just heard from our old friend Stephan. He is doing well and finishing up his PhD in Welding Engineering. We don't hear from him because his is a busy lad with new responsibilities at work and serving as the chairperson on several international welding committees.

I will say that I miss his participation in this forum.

Parent - By welderbrent (*****) Date 04-07-2018 17:48
Amen.  Glad he is doing well and taking his career to new heights. 

Parent - - By jwright650 (*****) Date 04-09-2018 13:46
Thanks for the update on our buddy Stephan. Glad to hear that he is doing well. Busy is usually a good thing, so we can forgive him for not dropping in to check on us here in the forum. :cool:
Parent - By 803056 (*****) Date 04-19-2018 17:38
Will do.

Parent - - By jrw159 (*****) Date 04-19-2018 15:11
  It is good to hear news of our friend Stephan! If you have the opportunity to speak with him again please tell him hello for me.

Parent - - By welderbrent (*****) Date 04-19-2018 19:37
So you found this one too.  Good.

Parent - By jrw159 (*****) Date 04-20-2018 12:59
  Yes and thanks again for the help my old friend (old as in known for some time). :grin:

Not really impressed with the new one. It's the second best around though.

Parent - - By DannyAgudelo (*) Date 04-07-2018 18:02 Edited 04-07-2018 18:08
Thank you for your reply.
But just to make sure i understand, the temperature on the table the temperature that the weld is going to be exposed to while in service,  or is it the temperature of the system which by being higher would generate more pressure on the pipe or vessel?
Parent - - By 803056 (*****) Date 04-07-2018 18:06
Assuming the heat is transferred through to the pipe wall (steels are not know for their insulating value), it would be the same from a design and code perspective.

Parent - - By DannyAgudelo (*) Date 04-07-2018 18:11
So as an example if a pressure vessel while in service is going to operate at 500° f, this same temperature would be the design temperature?
Parent - - By 803056 (*****) Date 04-07-2018 18:20
If the vessel is a code stamped vessel, the information is stamped on the name plate. The design drawings would also list the information.

In the case of ASME B31.3 the information would also include the fluid service class.

Best regards - Al
Parent - - By DannyAgudelo (*) Date 04-07-2018 19:12
I understand but to my question regarding a vessel or a pipe, would the 500° f be the design temperature. My exact question is, exactly what is the design temperature. Is it the range of temperature at which the vessel or pipe is going to operate? Is maximum design temperature the maximum temp to which it might rise? And if its not, what exactly is design temperature...

Thank you
Parent - - By 803056 (*****) Date 04-07-2018 19:47
I believe it is the maximum temperature used for the purpose of design calculations. The operating pressure and temperatures should not exceed the design parameters. It is best that you look in the applicable code and look up the definition of the term you are looking for.

Parent - By DannyAgudelo (*) Date 04-07-2018 20:08
Thank you
Up Topic Welding Industry / Inspection & Qualification / Welding Inspection Maximum Reinforcement

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