Tightening the nuts on the bolts.

[Syahar1975]

Dear Engineers,

We have 4 bolts on 2" A105 blind flange.

The pressure on the blind flange is 30 PSI.

The question is how much maximum torque in LB foot or NM or KgfM could be applied to each of bolts.

Could we used this equation :

4 bolts = 30 PSI so 1 bolts 30/4 PSI = 7.5 PSI

The maximum torques could be applied is 7.5 PSI x Volume of the thread of the bolts.

Syah

 

[drawoh]

Syahar1975,

What is your level of training? Are you are an engineer or just a drafter? You are asking an awfully basic question.

You are evaluating pressure resistance. How about your bolts coming loose? IF your bolts are to remain tight, you should tighten them as much as possible, i.e. somewhere close to their yield/proof stress.

Check out

http://boltscience.com.

--
JHG

 

[dgallup]

What size are your bolts? That is what will determine the maximum torque you can tighten them to.

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The Help for this program was created in Windows Help format, which depends on a feature that isn't included in this version of Windows.

 

[Tmoose]

As others said, the bolt size and pitch needs to be known.

And the bolt material.

Is there a gasket in there somewhere? What is the material ?
Gasket materials require some minimum compression to maacroscopically conform to the surfaces to be sealed
Is the gasket protected from over compression ? Does it need to be ?

https://rennlist.com/forums/attachm...n-gasket-squished-enough-to-leak-img_6752.jpg

https://www.cherokeeforum.com/attac...il-pan-gasket-3rd-fail-pictures-untitled1.jpg

 

[Compositepro]

The actual pressure in a pipe almost never has anything to do with bolt torque used.

 

[dhengr]

Syahar1975:
You should really take your original question and thinking to your boss, and discuss the whole issue with him/her. They should know what you know, and what you don’t know, so they can give you proper guidance and keep you and your company out of serious trouble. The internet and E-Tips should not (may not) be the best place for this basic education. For starters, what’s the difference btwn. a force and a pressure, regarding the four bolts? Four bolts, whatever size, you didn’t say, don’t seem like enough bolts in a blind flange, whatever its size/dia., you didn’t say. A 90° spacing btwn. bolts may be a kinda large spacing for most flanges. You should really not be pretending to be doing engineering when you are so lacking in engineering understanding, and when you don’t have any idea what you are doing, that can be dangerous.

 

[XL83NL]

You should rethink if youre the appropriate person in charge to deal with such matters/questions. Given the amount of posts, # of years of membership on ET, and post provided, this question is indeed too far off.

 

[rb1957]

as others have said … a simple problem, and astonishing bad use of the available data.

what's the area of the flange, that is feeling the pressure =Ain2. p*A gives you the pressure load, /4 gives you some idea of the fastener load, *2 might be good to account for effects(like prying). Knowing the fastener load you can estimate the required torque as =P*d/5 ("d" is diameter of bolt) *2 is good to cover variations in loading.

So now you know the torque, and the bolt load = 2P … then you then pick a bolt of the size assumed (remember d = bolt diameter)

another day in paradise, or is paradise one day closer ?

 

[SnTMan]

The maximum torques could be applied is 7.5 PSI x Volume of the thread of the bolts.

Well, the units work out anyway

Regards,

Mike

The problem with sloppy work is that the supply FAR EXCEEDS the demand