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By pipewelder_1999 (****)

Date 07-11-2016 14:20

If I remember correctly, we were taught that is C-School and it was based upon heat input limitations. Some of the welding procedures from NNSY and PSNSY controlled heat input for HY80 and also specified a minimum and maximum length of electrode meltoff for a given length of weld .

Procedures were the only restrictions I ever recall however I may not be sure about NS 250-1500 and NAVSEA 389-0317.

The requirements for bead width are pretty slim as far as a variable for procedure qualification. Heat input was referred to however the statement doesn't refer to bead width (which may not be an accurate variable related to heat input).

"From 248"
"Heat input requirements shall be specified for base materials with toughness
requirements. Combination limits of amperage, voltage and travel speed shall
be specified for the ranges of each parameter. Equivalent means of limiting
heat input (for example, nomographs or for shielded metal-arc, bead length
methods) are permissible. Simple reference to a formula is unacceptable.
Requirements for heat input shall comply with the applicable fabrication
document in all cases. "

Many times the things we are taught in schools stick with us and we never check out the sources other than what the instructor said.

Have a good day.

Gerald

By Lawrence (*****)

Date 07-11-2016 15:20

I think Gerald may have hit on it.

Weaving may not be specifically mentioned, However; When you weave from side to side it takes longer to get from point A to point B right? So if a weave is placed rather than a stringer, it may violate the WPS limitations for travel speed eh?

If the current is within the WPS range, slowing down the travel speed to weave may put more heat into the weldment than was proven with the PQR.

Meaning; Weaving may be prohibited by virtue of the WPS travel speed limitations.

By 803056

Date 07-12-2016 19:42

There are no limitations on the width of a weld bead deposited with SMAW in D1.1, ASME (exception Section VIII, repair on a vessel that has been subject to PWHT), or NAVSEA TP278 unless there are notch toughness requirements imposed. There are restrictions in the form of heat input limitations when notch toughness requirements are imposed. Most of us know heat input is a function of voltage, amperage, travel speed, and an often overlooked factor: efficiency factor that considers how energy actually goes into the weld poor versus how much is lost through radiation, into the electrode, etc.). There is no direct consideration of the bead width or weave width in the heat input equation.

Heat input also comes into play when welding Q&T steels. NAVSEA TP278 limits the heat input based on the thickness of HY80, HY100, etc. Controlling the heat input involves controlling the travel speed, but that does not necessarily limit the width of the bead as a function of the diameter of the electrode. I've heard many times that the "code" limits the width to 2X, 3X, or even 4X the diameter of the electrode. I've yet to find such limitations in D1.1 or NAVSEA TP278.

Don't get me wrong, I believe in placing controls on the welding parameters when there is a reason to do so if for no other reason to ensure consistent results from one welder to another. Workmanship, often not address by welding standards, is an important aspect of producing a product that appeals to the purchaser's sense of "quality". After all, how many of us have encountered clients that have said something to the effect, "I might not be a welder, but I know what a good weld looks like." Nothing catches the eye like seeing one weld deposited using stringers and another weld right beside the first that is a wide weave. How many of us look the welds that are visible as we walk through the airport or shopping mall? How do we respond when we see wide weave beads and stringers intermixed on the same member or the same connection?

The bottom line is if the contractor wants to limit the width of a weave bead as a function of the electrode diameter, so be it, but let's call a monkey a monkey, an apple an apple, and BS for what it is. If the contractor wants to limit the width of the weave, that's fine, but it is the contractor's preference, not a code requirement.

Best regards - Al

By pipewelder_1999 (****)

Date 07-12-2016 22:27

For SMAW, I believe the only code or specification in which one will find the mysterious 2-1/2" times the core wire diameter limitation is in AWS A5.1.