AISC / API Allowable Deflection

[engpes]

I have a 60 ft long skid constructed from W12@50 I Beams. I am running a single point lifting analysis.

What is the more strengent maximum allowable deflection per AISC or API? Is it Length/250?

Thanks.

 

[dhengr]

engpes:
You must be pretty confident of your C.G. calcs. if you are going to lift a 60' long skid from one point. You’ll have at least a 30' + long cantilever on one end or the other, on a couple W12x50 WF beams, plus whatever is going on in the other directions. That sounds pretty long and light. This is a 3D stress and deflection problem. The deflection limit has much more to do with what your equip. and piping will tolerate at its various points of attachment, as long as you don’t over stress the skid. AISC won’t be of any help to you, API may have some deflection criteria. Call your friendly rigger and ask him how he would like to life what your skid looks like and weighs.

 

[engpes]

Sorry, I wasnt clear. The lifting set connects to the skid at four points and all tie in to a single lifting eye.

The actual span between the connection points is only 40 ft.

Thanks.