Lifting lugs calculation: out of plane force

[FPPE]

Dears,

Could you please share standard to refer to when calculating the out-of-plane force in lugs (Fz in the following image)?

Some claims to consider 10% of the resultant force in lug plane.

I'm designing the lifting of an heat exchanger and, due to the stacked support saddles and given the amount of nozzles, there is no space to install two longitudinal lugs and the only solutions are trunnions or 4 transverse lugs (using a spreader beam).

Thanks in advance

 

[r6155]

Try to avoid lifting lug. Use slings hugging the shell.

Regards

 

[JStephen]

If the geometry of the hoist lines is known, you can slant the lug to match and avoid a lot of the issues.

 

[VFK]

API-RP-2A (offshore lifts) uses 5% of sling load for out-of-plane bending. Client specs tend to nominate the amount.

 

[IdanPV]

The out-of-plane force may result in a high bending stress.
If possible, try to avoid that by lifting the equipment using a dedicated lifting tool which will force lifting in the Y direction only.

 

[Trestala]

Our practice is to use 5% out-of-plane bending in the calculation, but in actual lifting that I've seen it has been larger angles considering the spreader beams that are available. You wouldn't know until you know what lifting equipment you'll have, so I agree with 10%.