Good morning Gentlemen;
Try as I might, I cannot find the clause in D1.1 that states interpass temperature is measured 1-inch from the point of initiation for the next weld bead.
Likewise, the edition of D1.8 I have, granted it isn't the current edition, states the maximum interpass temperature is measured 1 to 3-inches from the joint. We don't have an over abundance of buildings constructed using the D1.8 seismic requirements, so I'll refrain from delving too deeply into that code.
The question has come up before regarding where the interpass temperature is measured when D1.1 is the governing standard. As of yet, the only measurement included in D1.1 is "(paraphrased), "a distance equal to the thickness of the thinner member, but no less than 3-inches from the weld joint." It would appear that dimension is applicable to both preheat and interpass temperature. Generally, the maximum interpass temperature isn't an issue with most of the steel alloys that are prequalified for steel framed buildings. One reason for the lack of concern is that notch toughness is not usually an issue with steel members enclosed within the building envelop.
The Bridge Code does include a statement regarding the distance from the weld joint for the maximum preheat temperature being measured 1-inch and 3-inches from the joint. It is interesting to note that there is no dimension listed for measuring the maximum interpass temperature.
However, since the post refers to tables included in D1.1, I am making a leap of faith and assuming the writer is asking the question with regards to AWS D1.1. I could be wrong, it has happened before.
It can be a mistake to apply the requirements of a different welding code on a project where that (different) code is not applicable. The verification inspector may find himself liable for the additional costs (if any) due to imposing requirements that are not included in the applicable code. An example that comes to mind is holding the contractor to a maximum interpass temperature when such a limitation is not listed by the WPS or the welding code referenced by the project contract documents. Even if the direction is well intended, the verification inspector must refrain from interfering with the contractor's responsibilities regarding the way and means of construction.
Best regards - Al
Al is correct of course but let me explain why I even mentioned it.
OP added that a 'Senior Supervisor' insisted their interpass was to be measured at 1". Code wise, that would be the case if D1.8 were in play for Demand Critical joints though Al noted that it is 1-3" whereas original preheat is 'not less than 3".' So the two could be closely related while being a touch different.
If a senior super has made a statement, it could be a company inclusion on the WPS or in a policy somewhere for them that can be an extension of the code so that even mentioning D1.8 would be mute.
While I understand D1.8 is not incurred often, it is involved more than some realize. On the other hand, it is often pushed where it is not intended to be included because the inspectors, BOTH QC and QA, are not understanding the scope of application of the code.
It is well for us to understand where certain ideas come from and then to find out from ALL of the applicable documents on the job whether or not it applies to the work in progress. Just because it was a Senior Super doesn't mean they are right no matter what, but, better to check out all the possibilities than to just come running here and then go back to the super and tell them they don't know what they are talking about. Or ignore them because you can't find it in one particular code.
He Is In Control, Have a Great Day, Brent
Dear Al
Appl Design/Const Code- AWS D1.1_2015 only
That's why I mentioned that it appeared you were asking the question in relation to AWS D1.1. It wasn't clear from your post.
Al
Topic Welding Industry / Technical Discussions / AWS D1.1_2015-Preheat and Interpass Temperature Measurement
