DTI calibration

[HSIII]

I have a client who is planning on using silicone-filled direct tension indicator washers for connections. The owner's QC guy is adamant that a skidmore is required to determine the number of refusals required at a specific tension, and that's the only way, hands down, no other way according to him.

I've always seen it done where the DTI was placed into a solid steel connection until refusal with the feeler gauge is met in most of the locations into the bolt shank. Once this is achieved, usually the amount of silicone emptied is noted and visually that is what's compared on the remaining bolts.

Both methods are acceptable, right?

 

[stanweld]

For slip critical joints the Skidmore is required per RCSC recomendations - one reason to verify squirter acceptability. What if it's counterfeit?

We just demonstrated on some "unused, not well stored", A325 bolts that bolt fracture occured before the squirter "squirted" or the required tension was obtained on the Skidmore. Trade name DTI's were required under the Contract.

 

[HSIII]

stanweld,

Just read over the newest edition of the RCSC...yep, you're right, right there in black and white.

Thanks.

 

[connectegr]

Contact Applied Bolting in Vermont. They are active participants on the RCSC Committee. I have visited their facilities and seen their QC process, and they make a reliable product. They can answer any questions you have.

http://www.FerrellEngineering.com