WisDOT - Overhead Sign Bridges - API-5L
WisDOT - Overhead Sign Bridges - API-5L
(OP)
Good Afternoon,
We are a contractor in Wisconsin that performs structural and miscellaneous steel work. For the Wisconsin DOT, we perform a lot of ornamental/structural railing. We have been recommended to build overhead sign bridges and similar structures. I'm currently having a very difficult time finding API-5L-X42 (American Petroleum Institute) spec pipe that is domestically manufactured per "Buy America" and which can be produced in the very limited quantities. The API pipe is used for the vertical posts and sometimes horizontal chords.
There must be a loop hole that I'm missing as I've contacted well over 30 manufactures and distributors. While I have found plenty of people that could make it, not a single one would take on making one or two 30' pipes. I've reviewed the WisDOT standard specification which requires API spec pipe also, so there is no standard substitution that is allowed. I've also reviewed the design requirements with an engineer that performs the structural drawings for some of the sign bridges; they're not aware of why the DOT uses API spec other than maybe because of how stringent the spec is. Lastly, I've reviewed the FHWA and found no nationwide waivers that apply to API pipe.
Does anyone know if A500 Grade B is being substituted or if the contractors are utilizing the .1% rule for the sign bridges or if there is something else missing?
Thank you very much for any help.
We are a contractor in Wisconsin that performs structural and miscellaneous steel work. For the Wisconsin DOT, we perform a lot of ornamental/structural railing. We have been recommended to build overhead sign bridges and similar structures. I'm currently having a very difficult time finding API-5L-X42 (American Petroleum Institute) spec pipe that is domestically manufactured per "Buy America" and which can be produced in the very limited quantities. The API pipe is used for the vertical posts and sometimes horizontal chords.
There must be a loop hole that I'm missing as I've contacted well over 30 manufactures and distributors. While I have found plenty of people that could make it, not a single one would take on making one or two 30' pipes. I've reviewed the WisDOT standard specification which requires API spec pipe also, so there is no standard substitution that is allowed. I've also reviewed the design requirements with an engineer that performs the structural drawings for some of the sign bridges; they're not aware of why the DOT uses API spec other than maybe because of how stringent the spec is. Lastly, I've reviewed the FHWA and found no nationwide waivers that apply to API pipe.
Does anyone know if A500 Grade B is being substituted or if the contractors are utilizing the .1% rule for the sign bridges or if there is something else missing?
Thank you very much for any help.






RE: WisDOT - Overhead Sign Bridges - API-5L
It’s their spec. and requirement, you’re their contractor, call them and ask, specifically someone in their engineering and design group. There should be no embarrassment in that. Many times those are feel-good requirements put in by someone who has no idea about the availability of the material they are spec’ing., some Governor’s/legislator’s aid fore example. Besides that, it’s a good idea for you to get to know a few people there on a first name basis, so you do have someone to go to with questions. Just do your own homework first so you don’t look silly for lack of effort; and it sounds like you’ve done that.
RE: WisDOT - Overhead Sign Bridges - API-5L
RE: WisDOT - Overhead Sign Bridges - API-5L
I got in contact with the proper channels within the WisDOT department. He stated the reason we specify API-5L-X42 is because of good charpy impact test and weld-ability as it relates to carbon equivalent. He continued to state that we are open to A500 pipe on a case by case basis if it were needed and he anticipates a change in the specifications for the chords of the sign trusses, due to the lack of availability in API pipe of that size. He also referenced the Pennsylvania spec which doesn't allow A500 pipe because A500 specifications states the tube may not be suitable for dynamic loading; but he doesn't believe this is a good enough reason to outright ban the pipe.
RE: WisDOT - Overhead Sign Bridges - API-5L
That’s about the answer I thought you would get, and you’ve made a new acquaintance, and actually heard his/her voice. You got a nice and apparently helpful and friendly answer to this question, and have made a good contact for any future questions. A500 pipe has good welding characteristics doesn’t it? Do any of your suppliers stock it with charpy tests as part of the mill certs? The things that will influence fatigue life and dynamic loading as much as anything are good clean weld detailing, good weld prep. and the quality of the welded joints. So do a good job on those, and you pretty much got er made. You’re fab’ing. to WisDOT’s designs and drawings aren’t you, so that’s not your responsibility, right?
RE: WisDOT - Overhead Sign Bridges - API-5L
SceneryDriver
RE: WisDOT - Overhead Sign Bridges - API-5L
I suspect that really isn’t a fair assessment of the real situation. I’ll bet pipe to an API Spec. was more available 4, 5 or 6 years ago. Have you seen or read anything lately about the oil and gas industry in Texas, North Dakota, etc., they are using a bunch of pipe to find you (or themselves) more oil and gas. Likewise, that spec may have been written to include a wider range of materials, with proper attention to details, without harming the end product. Narrow spec. writing and ‘buy America’ are not always virtues, in this day and age, if you want to get things built. Nor do I believe that quick, cheap and dirty is the right way to go if we want safe structures and designs.
RE: WisDOT - Overhead Sign Bridges - API-5L
Why not ask your stockist what grade of pipe he can supply in one or two lengths and check the speed and material properties for charpy values.
You might be able to get Api 5L grade B (basically x 35) and just make it a bit (20%) thicker? AX42 was only 20% better than the base level grade B, once higher grades became available at more or less the same cost per ton, every one went for less cost.
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: WisDOT - Overhead Sign Bridges - API-5L
You would normally find line pipe comes with charpy tests at -20.
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way