Does the Square washers need to be welded to the top compression ring of Towers

[Fieldmech]

On the Vessel Towers, the vendor provided square washers on top of anchor bolts for compression ring. They are advising us to weld the square washers to the top compression plate. The each anchor bolt on the Vessel will also be bolted with two nuts over the square washers.

Please advise on tall towers if welding of square nut to the top compression plate is required.

Also if required can they be tack welded or does it have to be fillet weld?

Is there any problem due to wind or cyclic service, if we don't weld the square washers.

Thank you in advance

 

[r6155]

Please, see PIP STE05121 Anchor Bolt Design Guide :
........A mechanism to transfer load from the base plate to the bolt without
slippage is incorporated (such as welding washers in place). If washers are
to be welded in place, plain washers or steel plate (rather than hardened
washers) must be specified to ensure that a good weld can be produced.
Galvanized or painted surfaces must be prepared appropriately before
welding. Welded elements may need to be painted or the galvanizing may
need to be repaired.

Regards
r6155

 

[Fieldmech]

Let me rephrase my question

Do we have to weld the washers on top of the compression plates? Is it acceptable to not weld them? What are the consequences if we don't weld them?

regards

 

[mk3223]

IMO, a tack welded washer may have a crevice corrosion issue because the painting or galvanizing under the washer are to be removed for the welding, and can't be repaired.

 

[r6155]

Fieldmech
1)You need to read in full PIP STE05121 OCT2006 55 pag in pdf,.
2)In general, two nuts per bolts are not required.
3)Ask your vendor why.

Regards
r6155