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Torque Multiplier

06/11/2012 7:42 AM

I came across a torque multiplier in our shop the other day. It's a 10:1 1/2" input drive 1" output drive. it states if you apply 200ft lbs it will output 2000ft lbs. has anyone used one of these successfully? Here is the reason i ask : We thermoform predominantly styrene cups and plates. The die that is attached to the melt pump has 30 bolts that are required to be torqued at 800ft lbs each. Well this crew has bee winging it. I went out and bought a Klutch 1" impact that is rated for 1600 ft lbs. I was told it didn't work and i'm guessing that they are radically over tighten the bolts.

I should be able to put a torque wrench on this multiplier and determine what they have these bolts snugged down to. If they require to exceed the 800ft lbs to stop the die from leaking styrene i'm guessing there is something wrong with the die.

This picture is quite similar to what we have

Thank you for assistance,

Bruce

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#1

Re: Torque Multiplier

06/11/2012 7:48 AM

What does it say on the calibration certificate?

<...Torque Multiplier...>

Isn't that just a fancy name for a "reduction gearbox"?

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#2

Re: Torque Multiplier

06/11/2012 9:44 AM

May we assume you're talking about something like these?

If so, it should work for your application if there is a good, secure place for the reaction bar to rest. 2 things:

1. Make sure the bolt/studs are lubricated before starting assembly,

2. Tighten the nuts evenly, in a pattern to spread the force, and in stages,

3. Get rid of the impact wrench for assembly - may be useful in disassembly. Ok, that's 3.

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#10
In reply to #2

Re: Torque Multiplier

06/12/2012 8:17 AM

ok, this sounds reasonable

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#3

Re: Torque Multiplier

06/11/2012 10:32 AM

The torque multiplier can be used, but you have to loosen the bolts first, then re-torque them (lubricated). Trying to read torque on an already tightened bolt, will only give you a larger torque figure and possibly, you may be end up over-torquing. When torquing, you must apply continuous force, (not starting and stopping).

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#12
In reply to #3

Re: Torque Multiplier

06/12/2012 8:23 AM

personally i think the bolts are being grossly over-torqued this is what i need to find out.

We are replacing the die with a temporary die in july at shut down and sending this one out for repairs. metal has been passed through the extruder and scored the die. I'm going to pick their brains for a procedure.

thx

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#4

Re: Torque Multiplier

06/11/2012 10:40 PM

Yes we use a torque multipliers fitting wheel nuts to our semi trailers they work well just remember it tested and recalibrated regularly.

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#11
In reply to #4

Re: Torque Multiplier

06/12/2012 8:19 AM

hmmm, this has been on a shelf for some time and if it was used it was used by hacks trust me! good point!!

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#5

Re: Torque Multiplier

06/11/2012 10:52 PM

Use exactly the correct lubricant, and remember that the reaction point will be taking the full (very large) force. Beware chains!

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#13
In reply to #5

Re: Torque Multiplier

06/12/2012 8:24 AM

This I need to find out. The used never seize on the last go round. i will check the specs

thx

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#6

Re: Torque Multiplier

06/12/2012 5:44 AM

This is yet another example of the continuing and pervasive misunderstanding of "torque"

The bolts are not tightened properly. "Properly" means not too tight nor too loose but rather, "just right". Assuming that the design engineer had correctly determined how tight "just right" needs to be, the problem is that you're likely not getting close to "just right" - not with the use of a calibrated torque wrench and certainly not with an impact gun (these latter tools-of-the-devil should be forever banished from precision workplaces).

One has to remember that torque is only a measurement of resistance felt as a fastener is tightened. As a previous comment stated, lubrication is a factor (one of many). However, it's not as simple as suggested: Without lube, the "proper torque" may result in a fastener that's too loose. Too much bolt goop and the fastener becomes too tight. But how much goo does one actually apply to the fastener? Where is it applied? What if the goo is contaminated? What if the threads are damaged? What if the thread tolerances are too loose or too tight? What if the joint is sprung? What if the components are rusty? And on and on...

It should become crystal clear to those who have a modicum of engineering sense that the relationship of torque to actual bolt load is a very dubious one at best. As such, it's quite common to find actual bolt stresses on similar fasteners in the same flange to be vastly different than their neighbours - even though they had all been torqued to the same value. What one should do is measure the effect of the process after tightening. Then, the inevitable inconsistencies can be dealt with by modifying the bolt tightening force accordingly. This must be done for each bolt.

Yes, the integrity of some joints can be based on assumptions, hopes, wishes and prayers. However, others actually require one to know how tight the bolts are.

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#14
In reply to #6

Re: Torque Multiplier

06/12/2012 8:28 AM

So what do you suggest using on 30 Bolts to be torqued to 800ft lbs?

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#7

Re: Torque Multiplier

06/12/2012 7:51 AM

Before you go any further, make sure that both your Torque Wrench and the Multiplier used are calibrated together as a single unit.

You will be amazed at the differences you will find by randomly matching the two.

Never mismatch the two after the proper way of calibrating the pair.

Don' believe, try it yourself.

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#9
In reply to #7

Re: Torque Multiplier

06/12/2012 8:16 AM

The manufacturer must recommend one. i will call them today thx

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#16
In reply to #9

Re: Torque Multiplier

06/12/2012 1:10 PM

There have been some interesting threads regarding Torque on the various forums floating around. If I get a chance, I will look around after work tonight and pass them on.

For example: http://cr4.globalspec.com/search/sitesearch?do=show&sort=textmatchrank&srch=torque&order=asc

I will search around for more, plus a specification or 2 and post through 4Shared.

Respectfully,

qaqcpipeman

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#20
In reply to #16

Re: Torque Multiplier

06/12/2012 2:59 PM

I would really appreciate that as i'm sure the others. There are so many variables to take into consideration if you are even going to be close. I have worked with some of the best in the maritime industry over the years but the best i seem to find are right here!

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#8

Re: Torque Multiplier

06/12/2012 8:14 AM

Thanks so much to All of You,

I'm going to tackle the manufacturers specs on this. There must be a torque sequence as well a procedure. this is the wrench we have:

This has been enlightening thank you

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#15
In reply to #8

Re: Torque Multiplier

06/12/2012 8:34 AM

This is made by CDI Torque Products 10:1 @ 2000ft lbs.

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#17

Re: Torque Multiplier

06/12/2012 2:09 PM

800 ft-lb? That's a bunch. I thought my trailer hitch ball was a lot at 250 ft-lb!

Consider using a "Super bolt." This may generically be called a jack bolt. It has several smaller bolts surrounding a large bolt. You do not torque the large bolt, just snug it; then torque the small ones to get the clamp load you need.

I think there is also a hydraulic torque wrench, but I don't know what clearances it needs.

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#19
In reply to #17

Re: Torque Multiplier

06/12/2012 2:55 PM

I do use those here but for this application its not feasible. I am going to pull up some specs on this. There have been some very enlightening do's and dont's tossed around.

I guess i would like to see if there is some sort of industry procedural standard so i can pass that along.

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#18

Re: Torque Multiplier

06/12/2012 2:47 PM

Enerpak manufacturers hydraulically driven torque wrenches, but they are very expensive. If you are experiencing problems, this might be a solution. They require a stationary point to push against, and they are heavy. But the size is not too bad. Common on underground pipe flange tightening. Good luck.

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#21

Re: Torque Multiplier

06/13/2012 4:08 AM

Sorry for missing the recent communication; I was out of 'net range yesterday.

People: You're still not getting it You can calibrate until the cows come home. You can use the most esoteric torquing patterns that you find. You can buy the most expensive torque tool from a convincing wrench salesman. Yet, in every case you'll continue to be guessing and hoping that your bolts will be tightened to the proper load. Then, when your joints leak you'll blame the die, the tool, the operator, the calibration lab and a number of others but you won't look at the actual problem. You're practising engineered voo-doo.

Consider the following "experiment": Lock a bolt's head into a vice. Thread a nut onto the end of the bolt. Spot-weld the nut to the bolt. Set your torque wrench to any value. Then, apply the wrench to the nut and apply force. If it's a dial-indicating torque wrench you'll clearly see the indicator clocking commensurate with the amount of force that's being applied. Stop when you've reached your target torque. Now, sit back for a moment and think about what you just did... You applied the right torque with a calibrated torque wrench. Based on conventional misguided "wisdom", if this bolt/nut combination was actually holding two halves of a flange together, the component would be tight, right? Wrong, wrong, WRONG

Because the nut didn't move up the thread of the bolt, there would have been no preloading of the bolt at all ~even though the proper torque was applied

Of course, nobody welds a nut onto a bolt before tightening. However, there are many other sources of less-severe resistance which will be encountered (as per my previous post). All will conspire against the incorrect perceived linear relationship between torque and bolt stress. It's a crap shoot!

Our Techs deal with this all of the time. In order to effectively seal critical joints (or non-critical nuisance joints), "torque" is only considered a target. After the initial tightening stage, the stress of each fastener is determined by measurement. The metric to measure is elongation. Unlike torque, a fastener's elongation is directly proportional to its stress. Any fasteners which haven't stretched to the necessary elongation are then torqued or tensioned further until they're within spec.

Elongation can be measured with dial indicators or, as our Technicians do, with specialized instrumentation.

The torquing process as commonly mis-understood by the majority of otherwise "enlightened" practitioners is an embarrassing aberration of engineering 'logic'. I can't think of any other procedure where a guess or an assumption of an outcome before the fact is acceptable. In all other cases, verification of some sort is paramount and demanded. Yet, when tightening components whose possible failure may adversely affect plant production at least or the health and safety of personnel or the community at most, many people's heads remain buried in the sand

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#23
In reply to #21

Re: Torque Multiplier

06/13/2012 8:32 AM

Good reply. Clamp load is what we are after.

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#25
In reply to #21

Re: Torque Multiplier

06/13/2012 10:11 AM

You (of course) are right on the money with your response. The problem with that method, is that any replacement of bolts would invalidate the existing measurements, unless identical bolts were used. Additionally, there is the question of permanent bolt stretch. Would the system require new bolts each time? Is there a point where the bolts have stretched beyond their limits?

How would you suggest that a facility that must clamp and re-clamp continuously approach the issue?

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#32
In reply to #25

Re: Torque Multiplier

06/13/2012 2:18 PM

"any replacement of bolts would invalidate the existing measurements"

Well yes, of course! Furthermore "identical bolts" are never identical when one looks (for example) for an elongation of .020" or so. This is why every bolt must be measured prior to tightening. After tightening, every bolt is re-measured. When using the specialized instrumentation, all readings are recorded in the device's memory. Thus, we can check for migration of bolt loads months later by simply pulling up the proper fastener ID in the unit and then measuring again. Thereby, anything which is out of tolerance can be "tuned" back to spec before it breaks or causes leakage

Most people don't understand that all bolts stretch when they are tightened. If they didn't you'd never be able to have a tight bolt! In essence, bolts act as springs; The tighter the spring, the more the clamp load. This stretch is directly proportional to bolt stress up to the Yield Point. If the fasteners are to be re-used (ie if the component is to be dis-assembled and then re-assembled), they should never be stretched beyond Yield. However, in some cases tightening beyond yield is actually required.

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#33
In reply to #25

Re: Torque Multiplier

06/13/2012 2:24 PM

First part: As long as the stretch is within the elastic limits, it should return to the pre-stretch length when the load is removed. This would include deformation of the threads, and I don't know if this is possible to determine.

Second part: Hasn't been mentioned yet that I have seen. How about heating to achieve some elongation, then snugging the nut including torque to assure things are seated, then when the bolt cools a load will be applied? Sort of like using hot rivets in structural framing.

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#34
In reply to #33

Re: Torque Multiplier

06/13/2012 2:38 PM

1: "I don't know if this is possible to determine". Indeed it is. You simply just measure it again. If this reading is the same as your initial reference measurement, the fastener hasn't yielded!

2."How about heating to achieve some elongation". This is typically practised on large fasteners such as those found on steam turbines and metal-forming presses. It requires a hole machined down the centre of the fastener into which a heating rod (gas, resistance or induction) is inserted. Another problem with this is that you have to wait for everything to cool down to ambient before measuring elongation. Not so good when you have a plant to run! With everything considered, the method isn't practical for this application. The required preload is low enough so that common tightening tools can be used.

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#38
In reply to #33

Re: Torque Multiplier

06/14/2012 7:19 AM

...as far as the heating part is concerned the bolts aren't torqued all the way until the die is up to operating temperature ie bolts as well. This has been a very low tech operation thus far. I'm blown away by all the considerations as well as the technical expertise of those like yourself Lehman57 thank you

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#22

Re: Torque Multiplier

06/13/2012 6:19 AM

@ Lauruz: Here's another option for you to consider...

These bolts change colour when the proper preload has been applied. They are factory-calibrated so that the indicator window becomes fully black once the correct bolt stress has been acheived. Thus, regardless of the input torque, you'll know that the fasteners have been tightened properly. Furthermore, you wouldn't even need to use a torque-indicating wrench.

The only cavaet with this type of bolt is that the colour change is subjective. You'll have to know how "black" black really is. For highly critical applications, bolt elongation measurement still provides a much better method of controlling bolt load (and, it provides a full process audit record). Nevertheless, for something like your dies, this could be an acceptable alternative.

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#29
In reply to #22

Re: Torque Multiplier

06/13/2012 10:52 AM

Considering we do have 30 bolts holding this thing together this may be a viable consideration but the bolts are recessed and Allen heads. I'm afraid that someone is going to get hurt with the present method they are using (two men and a big azz bar) this scares me. We are not stranded up in the Klondike!

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#31
In reply to #22

Re: Torque Multiplier

06/13/2012 12:36 PM

I will be contacting you for quotes :)

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#35
In reply to #22

Re: Torque Multiplier

06/13/2012 3:44 PM

Considering all that I have read here this seems to be the most plausible answer. However, applying it to my current die is another issue in itself. The bolt heads protruding above the die face is not an issue, it would require spacers.

I'm very interested in the hydraulic torque tools you sport on your web site. It looks like high quality tools.

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#36
In reply to #35

Re: Torque Multiplier

06/14/2012 4:07 AM

Hydraulic torque wrenches are indeed very useful. However, I think that in shops where the number of relatively high-load bolted joints is few or where frequency of use is low, they may be a bit of an overkill since, as somebody had mentioned earlier, they can be quite expensive.

If you're confident that the torque multiplier will be used in a safe manner, you may wish to save some money and tighten your bolts with it, rather than with something new. A pneumatic torque wrench (these are different animals than pneumatic impact guns), on the other hand, would be a better choice if the thought of the multiplier gives you concern. This variant develops a slow and easy rotation of the fastener rather than the "give 'er hell" explosion of uncontrolled energy that you'll get from an impact gun. The former is advantageous for fine adjustments of preload.

The important point to keep in mind is that any bolt tightening tool would work (including the use of the old "cheater bar"!) as long as one then also uses a proper method to verify and tune the preload.

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#37
In reply to #36

Re: Torque Multiplier

06/14/2012 6:39 AM

1st, I can't believe you would even mention the unsafe cheater bar, as some might consider it a recommendation and that you condone it's use. I have seen many bruised hands & other body parts, a few concussions, and some broken body joints with a cheater bar slipping. Catch you using one during a visit to for one of my clients doing QA or QC and I will NOT accept your finished product until you disassemble and re-torque to my satisfaction. Proper torque application is a science, let's explore it safely.

The vendor that I had a residence contract with last year for Shell Appalachia bought a Hi-Torque Hydraulic wrench with 4 sockets to safe money. Twas funny that 2 hands could torque the old way, but they needed 4 to run the machine, and with slippage, odd angles, and just putting anyone on the tool, it was found after an intensive time study that it took twice as long to assemble the GPUs they were building.

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#39
In reply to #37

Re: Torque Multiplier

06/14/2012 7:30 AM

That was our experience too.........

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#41
In reply to #39

Re: Torque Multiplier

06/14/2012 7:42 AM

I think the owner of the shop just liked toys. I tried to set up a meeting with the salesman to discuss Shell's needs, but he could not wait to get out of the shop.

His sales office was within a 1/2 a mile from our PA Headquarters. That effort added one more level of concern and my contiued avoidance of the companies who sell the products to minimize the efforts of torquing.

I may have missed the comment on torquing sequence, if they were made, but that is another most important part of a great torquing program.

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#42
In reply to #41

Re: Torque Multiplier

06/14/2012 9:51 AM

I don't think torquing sequence was mentioned, but it certainly is important. Sequence should be a criss-cross, not every one in line. Also tightening should be in several steps, not all at once.

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#43
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Re: Torque Multiplier

06/14/2012 11:50 AM

Here is a link to an Installation Procedure.

http://www.4shared.com/office/HIquF6Rr/Installation_Procedure_For_Hig.html

I am sure everyone has a chart with patterns that are usually used.

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#44
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Re: Torque Multiplier

06/14/2012 12:17 PM

This procedure is for structural bolting in which the focus is shear control rather than clamp control. Sometimes, such procedures also address the latter. However, the civil engineer's approach to this issue has got to be one of the most ridiculous: Their QA is based on the fastener having to be "snug tight" before the next step in the procedure. The latter is, in fact, quite accurate but since it depends on the subjectivity of the former, the end result of the process is fraught with overall uncertainty

Don't get too hung-up on "pattern tightening". It alone alone will not ensure accuracy of bolt load. Its true benefit is promotion of even joint/gasket compression and thus avoiding "cocking" which can bind a joint or damage a gasket. On large flanges, a very effective alternative is to use bolt tensioners which can tighten at least 50% of a flange's fasteners simultaneously (under certain conditions, even 100% of the fasteners can be tightened at the same time).

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#45
In reply to #44

Re: Torque Multiplier

06/14/2012 12:43 PM

I am usually loathe to work with firms that promote tensioning equipment, because working with Westinghouse Nuclear on some of the 1st tensioners many years ago, I seen the propensity for overstretching bolts and even needing massive hydraulic equipment to remove a tensioned bolt. Could have been many reasons, but another company near me, previously called Bolt-Tech, now owned by Mannings has even recently created problems for facilities that I worked on.

This has been an interesting thread, but maybe we are overworking it.

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#46
In reply to #45

Re: Torque Multiplier

06/14/2012 1:58 PM

No no, please continue. I have been concerned for years about the licence plates on my car falling off. ( Just kidding, this thread has taught me things about the subject I did not know, and I thought I was on top of things understanding bolt stretch.)

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#47
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Re: Torque Multiplier

06/14/2012 2:05 PM

Lol, I bought a new truck in OH while working out there last year, front and back plates, something new to me.

The rear plate lost one screw within a couple of months and perplexed me because of all of the plastic. I had to buy an oversize nylon machine bolt to get any type of hold in the formerly threaded hole. Of course, I could have over engineered it and spent a 100 bucks or so. The dealer used common screws and tore the hole and thread up.

I learned something there too.

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#48
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Re: Torque Multiplier

06/14/2012 2:09 PM

Probably should have used the bolts from post 22. Perhaps color coordination them.

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#49
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Re: Torque Multiplier

06/16/2012 3:12 PM

I come may be a bit late but I think that there are some remarks to be done:

- if you had a bad experience many years ago that does not mean that today's tensioners are as the 1st versions so may be you should review your position

- if a tensioner overstretch a bolt this ONLY due to the wrong usage made by un skilled personnel since the device brings ONLY the force to stretch and if this is too big then the user programmed it so. This in fact the advantage of hydraulic tensioning since several bolts can be loaded with equal forces (within the friction and dimensional dispersion of hydraulic cylinders used ) as pressure is in the system every where the same. Which is not the case of torquing.

- for big bolts tensioning is the best approach if it is justified (I apologize if I support a principle you do not like but I think one has to be objective).

- the pulling force to stretch the bolt so that the nut will become free is the SAME as the one used to stretch it at assembly I do not understand why the systems to remove the bolt have to be more massive than the one used to generate the initial stretching.

- in fact there is NOT a generally valid BEST solution for tightening ! The solution depends on many factors as how important is the assembly, how dynamic is the load, how often the assembly will be disassembled and reassembled, if the same bolt has to be reused or every time a new one must be tightened and so on, the list goes on the last but not least criterion being economical since the cost has to match the needs.

- there are procedures which can reduce the uncertainty of preloading when bolts are torqued (Boltintegrity does not like it since he is more involved in tensioning), the most current one is the torque-angle procedure which is based on a limited torquing (usually up to 1/5 - 1/3 of the torque estimated for the final preload) and a tightening by angle to the end preload. This procedure decreases in an important way the uncertainty and has the advantage to use classical tools (any type of torquing tool) and a short operation time since the installation of the tightening devices is not always so short as it is claimed.

- a last remark not related to your comments but to an other: the thread deformation does not influence in any way the length of the bolt under stress, in such measurements one does not take the parts as reference but the OTHER end of the bolt and this bolt "core" is parallel to the threads not in series so that ... the uncertainty is ONLY related to the parallelism of the 2 ends and the un-precision of the used device.

- it would be of great interest to know what kind of problems were created by Bolt-Tech / Mannings it could happen that either tensioner' s concept or personnel skills or even procedures were bad. If it would be as you claim the number of places where tensioning is used would not be so huge in many industrial directions.

As for the concerned application I consider that the use of a torque amplifier could be the optimal solution if the uniformity of the preload has not to be very high. The problem is more in the direction of the assembly-disassembly-reassembly of the tool.

The specific load on the threads flank are very high if the bolt is designed in an economical way. I made myself some tests to determine how friction grows up as function of tightening operations on same bolts. If the lubrication is not the right one the friction becomes such that the preload after about 4 operations is no mote than 1/4 of the first obtained value. I think this is an aspect to be considered as important and which could lead to other solutions. An estimation should be done. With a high pressure lubrication (MoS2 or Graphite or PTFE and a grease matched with the temperature) a bolt can be used many more times but not for ever!

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#40
In reply to #37

Re: Torque Multiplier

06/14/2012 7:36 AM

You're absolutely right, qaqcpipeman. In the interest of trying to make a point I was wrong in even mentioning the cheater bar .

Notwithstanding, it appears that the point was missed. 'Proper torque application' as conventionally practised is not a science but rather an exercise in engineered black magic. The point that I had wanted to make was that regardless of how you turn a nut, the desired end result is the required bolt load. By measuring this load after it has been applied by whatever means, one is able to "tune" the application force to then generate the correct load. At that point, the load is once again measured. If it's still out of tolerance, the process is repeated until you get to where you need to be. In some cases, for example with the load-indicating bolts or when placing the Ultrasonic transducer on the fastener while tightening, monitoring can be done in 'real time'. This eliminates "hunting".

If a QA review primarily concerns itself with the torquing procedure and whether or not calibrated wrenches were used, it isn't worth the paper that the Inspector commits his name onto. Signing-off this way would be basing the safety and reliability of the joint on mere guesses. If an Inspector sees that all bolts on a particular joint have been torqued to the same value, alarm bells and blinding lights should go off immediately; On the other hand, when one sees that the input torque had been different for each bolt, then one can relax before asking to see the table of individual bolt elongations. Further verification would require the Inspector to then review the acoustic signal records from the UT device to ensure that the Operator truly knew what he was doing rather than having had just "cooked" some numbers to satisfy a procedural spec. The latter often happens when the Inspector isn't suitably trained to know what he is looking for.

Some may say that the above is vast over-kill. I agree that this true for non-critical joints. But on critical connections, anything less could result in 'people-kill'. Then, an Expert Witness for the aggrieved party would chew-up and have the Contractor, Inspector and Owner for breakfast

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#24

Re: Torque Multiplier

06/13/2012 9:08 AM

I have dealt with everything from cheap imported non calibrated wrenches through "SuperBolt" (based near me in Carnegie, PA), high torque devices, hydraulic multi head devices to Tensioning studs in Nuclear Power Plants.

The more I seen, the more misconceptions I discovered, many improperly assembled machines and devices, the more intrigued I became, making a study and doing many tests on my own.

I am not well convinced of the accuracy of the cutesy dye releasing devices or the press film type indicators on the market, but I won't belittle them.

Any manufacturer, engineering firm, or constructor worth their salt should have a great procedure in place.

One that identifies the seriousness of the need, the safety issues involved, and a truly realistic view of what is desired and required.

I see misconceptions with almost all vendors, and a lot of it is caused by bad verbiage or not explaining the intent.

For example, about 3 months ago I generated an NCR against an International Company while doing Quality Assurance for an International E&G Firm.

The intent was there, and I understood it, but the verbiage was so bad that arguments began and are ongoing.

We are talking about a Billion Dollar Project at a standstill!

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#26

Re: Torque Multiplier

06/13/2012 10:18 AM

Would it be practical to employ pneumatic clamping? Certainly expensive to convert to, but, the savings in labor, and consistency would soon cover that cost I would think.

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#27
In reply to #26

Re: Torque Multiplier

06/13/2012 10:33 AM

Hi Bob,

I'm unfamiliar with that method but I don't think it would apply to our application since they have successfully been using the bolts for a number of years. I think I would depend on the bolt more than a secondary source of power in this application.

I'm going to print out this thread and have our whole team read this..........

Do you have a resource for these clamps you speak of? I'd be interested in exploring them out.

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#28
In reply to #27

Re: Torque Multiplier

06/13/2012 10:43 AM

MSC and Grainger both sell pneumatic clamps. Think of an air cylinder in place of a threaded rod on a C clamp. By applying a specific amount of air to the cylinder, there would be a specific clamping force. If the minimum amount of air was not achieved, the next step in the process would not be functional. Time constraints now. I will look up some pneumatic clamps later if you still need.

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#30

Re: Torque Multiplier

06/13/2012 12:20 PM

This item can pull 16,000 lbs. The company listed might have some solutions for you. Pneumatic/Hydraulic Straight-Line Action Clamps

Description: Straight Line Clamps; Port Size: 1/8 NPT; Holding Capacity: 16,000; Type: Straight Line Action Clamps; No Description: 21; No Description: 2-3/4; No Description: 1

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MSC #: 89305247

Order Qty of 1 = (1) Unit

Price: $585.98 ea

In stock: 5

Mfr: De-Sta-Co

Mfr #: 850

Qty:

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#50
In reply to #30

Re: Torque Multiplier

07/31/2012 1:57 PM

]Nothing more than a bolt would appear to have any practicality in our die..its bolts or bust due to a variety of factors. Not to mention it operates at around 400 degrees. I will keep this in mind for other projects though.

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#51
In reply to #50

Re: Torque Multiplier

07/31/2012 10:44 PM

At 400 degrees, it would need to hydraulics, not pneumatics, The beauty of this type of clamping is the speed, accuracy, and repeatability.

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