Lift Lug with Pad 1

[htman]

When designing a lift lug for a heat exchanger or pressure vessel is the lug required to be welded to the shell? (like a nozzle and reinforcing pad design)

OR does the lift lug sit "on top" of the pad? With the lug welded only to the pad and the pad is then welded to the vessel. (like a wear pad on a support design)

Thanks!

 

[waskillywabbit]

I've done both, just depends on the situation and type of lift attachment, lug or trunnion.

 

[TomBarsh]

Remember that when the lug or trunnion sits on top of the reinforcing pad that the pad must transfer the total load. In this case it's best to do some sort of check to confirm that it is adequate.

 

[stanweld]

The repad on a nozzle attachement is used to compensate for the hole (removed material) in the shell and has no bearing in the use of a pad for a lifting lug. The pad for a lifting lug is used to transfer the lift loads to a greater cross sectional area.

 

[htman]

So if you have two designs with the same thickness, but one has the lug on top of the pad and one has the lug set through the pad. Which is the superior design?

 

[SnTMan]

htman, in my opinion, the lug thru the pad is the superior design. However, as with all things, the superior design is not always required. If it's a heavy vessel, I'd go with it, if not, it may not be worth the added expense.

Regards,

Mike

 

[TomBarsh]

Good reply SnTMan.

 

[SnTMan]

Tom, thanks. Don't ask me to define heavy though