bolt tensioner

[leedrong]

Dear all ~!

We designed M90 stud bolt and heavy nus for tightening two flanges with bolt tensioner . End user request to add Belleville spring washers .
But if we use Belleville washers , Tentioner side washer absorb some of tension when tentioner released because this side nut turned by hand force during opposit side on pressing.
So we could not control the tension value exactly.
We have 3 ideas ,Case 1) use 2spring washers only at opposit side of tensioner and add a nut on tesioner side .
Case 2) Use torque wrench for bolt tightening and not use bolt tensioner. 3) Bolt tightening with bolt tensioner and after that add torque wrench tightening as much the value absorbed of tensioner side washer .

Which case would be the best to get exact tightening with
target value.

 

[MikeHalloran]

If you actually need an exact tension, it's best to make it happen by using the lowest 'spring rate' possible to do so, and to use some indicator other than wrench torque to estimate the tension.

That said, the force available from stretching a bolt between flanges is typically pretty large relative to the force available from a single Belleville washer.

Do you and your end user even agree on what you're trying to do?




Mike Halloran
Pembroke Pines, FL, USA