spreader beam

[blrmkr34]

I am builing a spreader beam for an 80k pick. The main beam is a w24x160x 40', the four spreaders are w24x131x12', My question is the weld procedure for fillet welds on lap joints.Pre heat 225, 70 series s.m.a.w rod,, 10 passes 100% coverage for all structural connections, three passes 100% coverage for all gussets, and full pen six passes 100% coverage for all lifting lugs. Is this description sufficient enough for my application, or do you see some red flags. Thank you

 

[dhengr]

blrmkr34:
I do know what a spreader beam is and what it is intended to do. Who did the structural design on your spreader beam, and to what industry std. or spec? Did you just happen to have a bunch of leftover W24's or do they really fit the need. You must provide a sketch and some details for anyone to have the vaguest idea what you are really talking about, and what your spreader beam system really looks like. The welding description is wholly inadequate for anyone to really build from. It appears that you could use some local engineering help on this problem from someone who has done some of this type of design before. We would be glad to try to be helpful here, but we really can’t do your design for you.

 

[westheimer1234]

spreader beam is use to lift modules (piperack modules, etc).. i have design one though because we only design upto the lifting lugs of modules..

 

[Zambo]

It doesn't seem like a normal WPS (weld procedure specification). You don't mention the steel type, but I doubt the 225 preheat is required for A36 or other carbon steel.

For the passes it will depend on the rod size so better just to state the weld dimension, the passes required will be determined by the welder as long as he follows the WPS.

The weld descriptions are also a bit confusing. For gussets they will be fillet welds. For structural guess these could be butt welds and lifting lugs I guess have a prep on the plate to allow a full pen weld , but your description is different for these 2 categories (perhaps the plate thicknesses are different).

 

[racookpe1978]

If it is a "below the hook" design for any heavy lifts, my company requires both a structural engineer (PE) and welding engineer sign off on the design.

Usually, they independently consult a rigging specialist (foreman or general foreman) about the "practicals" and shipping needs of the proposed design before plans are finalized. That's so it really can be used when it gets to the field. Capacity limits, rigging instructions, initial and periodic NDE testing are part of those drawings - and you don't have those indicated either.

Field engineers are not allowed to change any spreaders or designed rigging. I'm a little hesitant about using this rig based on the descriptions I read above.

 

[Zambo]

racookpe1978

good point about NDE. If the gussets and the lifting lugs were designed as fillet welds both could be easily tested using MPI (or dye pen), I'm not sure what the structural welds are for, if to lengthen the available beams then maybe butt welds are required if not then maybe fillets also and everything can be tested using MPI.

 

[blrmkr34]

My sincere apologies. I thought the less specific the better.
All data has been calculated. My concern is the the thickness of the flanges, 1 1/2", 1" during the weld process. Is "cold cracking" going to present itself?

 

[dhengr]

blrmkr34:
To answer your latest question; yes it could.
No apologies are rqr’d. But, it never ceases to amaze me that people want specific answers, or advise, to indeterminate questions, without giving any, or nearly enough, “specific” info. It suggests insufficient understanding of the problem because the OP doesn’t even give enough info. to facilitate a meaningful exchange. You can see the drawings, we can’t. I’m not trying to pry into your design, but the info. you gave in your OP left a fair question as to whether the spreader system or the welds were properly designed. The welds were certainly not called out in a way suggesting they were properly designed. Thus my questions, so we could see what welds you were talking about and how they were sized, detailed and loaded. I can’t imagine how you could expect a meaningful exchange of info. given what you have told us. All we know is that you have some W24's welded together, somehow, and is that O.K.? Sure.
Good Luck