One more thing. It's so obvious that I didn't even bother to note it: "lock" the both the lower and upper studs onto the coupling with a nut at either end. You'll have a convoluted mess which should actually be replaced by a new stud with the proper length but, at least by tensioning this mess...
jhamil1,
With all due respect, this "solution" is nothing of the kind. Punching the treads will likely not stop the stud turning within the nut, bottoming out on the top of the lower stud and then spreading and twisting the coupling into oblivion. At the very least, the threads will be so...
miningman,
You wouldn't happen to be pulling "the good stuff" out of the Carlin Trend, would you? If so, I'll be there at one of the properties next week on a training contract and would be happy to meet with you before flying home.
Ciao,
HevïGuy
www.heviitech.com
Ouch!
Initial gut feel is that the sizes were incompatible (and possibly exacerbated by conditions noted above). It'd be interesting to know whether the degree of resistance felt when turning the nut down was greater than expected.
"Made in China?" Maybe the heat was contaminated by melamine...
Transient1:
The other thing which is important in this situation is the original preload of the fastener. How close to yield is it? A 50% excursion may take it in to yield. Consequently, no, the fastener will not return to its original condition.
Ciao,
HevïGuy
www.heviitech.com
Hello miningman,
First: It's good to see you here and to know that your property hasn't gone on Care & Maintenance as so many others have!
Second: I promise not to mount my "Torque is Evil" pulpit ;-)
Indeed, it's frustrating! However, such a loose procedure is not to be unexpected in an...
You're not going to get "elasticity" without preload! In most cases, the more, the better (within the limits of the fastener's strength).
Two things must be considered:
the stiffness of the bolt
the stiffness of the components being clamped
The component's stiffness must be greater than...
Not a problem at all on either point:
One really can't practically calculate the required torque necessary to accurately achieve a desired bolt stress (one can never know what the K factor will actually be). An educated stab-in-the dark is necessary. However, the answer to the second wish...
Being on the same page, I think that mkkessel had meant to add: "...or by simultaneous bolt tensioning (or a high percentage thereof)"
Ciao,
HevïGuy
www.heviitech.com
C'mon folks: Although you're getting torque values from the "experts" you've got to take this with a huge grain of salt: "torque" does not and cannot be considered as a metric of applied load!. It's "preload that you must be concerned with. The most practical way to verify preload is to measure...
Hello Pulpeng,
It's a relatively costly option but, have you considered Hydraulic Nuts?
Actual "tightening" and "untightening" is the biggest user of time in any such process - even with slip-on nuts as described above.
Hydraulic Nuts replace standard hex nuts. Once they're all spun down...
Jhamil,
Please forgive my absolute ignorance but, I simply can't grasp how you're going to preload the top-half of this foundation-bolt configuration to 40,000 psi without the other end of the stud being afixed. [ponder]
If you run the new stud into the coupling and leave 1" or so between the...
Metcorr:
Of course, it's very important to review the design. However don't get hung-up on this to the detriment of other major variable: Procedure.
The poor gasket is often the first to be pinned with the blame when something goes awry. Concurrent to your design analysis make sure that you...
Gasket creep, perhaps?
Although there may have been sufficent load applied to prevent leakage for the first few months, creep may have resulted in bolt load-loss.
Assuming that the designer had put in enough meat into his specified load to compensate for future load loss, it may be moot if...
jhamil, Some more details please:
What you mean the nut failed? The bolt was okay?!
"B" what ?
How do you know the nut (or bolt, perhaps?) failed at 40,000 psi?
Just how did the "...stud apply 2500 ft-lbs to the nut"??
Ciao,
HevïGuy
www.heviitech.com
I've never tried to upload a file to the forum but, I'll give it a shot.
If successful, you'll see that the file contains an Excel spreadsheet that'll help you along. It shows you the intimate relationship of certain important variables. It allows you to calculate torque (for one thing) based...
etchyHA, seem to recall
I seem to recall a compendium of equipment steam rates but I've no idea where that may be. Even this wouldn't be very good to you since rates depend on the size of the component, heat rise etc (hence the link giving you the opportunity to calculate consumption based on...
Hello Dan and Greg,
It seems that you've mis-posted. The proper thread is at: thread404-229718. Nevertheless, here is my answer (which I had thought I already answered)
In the absence of something that addresses this obvious problem, I tighten my lug nuts on a wing and a prayer - with...
Giuss,
I've come late to the party. Nevertheless, I'll throw something out here as well:
You've indicated that everything is identical on this joint as it is on others which haven't failed. You've also mentioned that the bolting procedure was the same. The trick, I suppose, is to determine...
