125# Flange Torque Specs 2

[aalcala19]

Does anyone happen to have a torque specs chart for 125# cast iron flanges or happen to know any info about torquing 125# flanges?? Ive looked everywhere online and no luck , im thinking these torque specs would be similar to the 150# class HELP PLEASE !!!

 

[rconner]

Probably not enough info here -- you may want to provide the code/specification for the "cast iron flanges", service pressures/temperatures, specific gasket and bolt selection etc. (to get meaningful help from folks maybe more knowledgeable than I).

 

[MJCronin]

allacala...

It is the fastener, not the flange that is torqued.

What is the specific material, length, diameter and type of fastener that is used ?

What is the code of construction ?

What is the max operating temperature and pressure expected ?

 

[racookpe1978]

"It is the fastener, not the flange that is torqued.

What is the specific material, length, diameter and type of fastener that is used ?"

I would disagree: True, it is the fastener that is being torqued to create a force, BUT it is the GASKET that both defines the AMOUNT of force needed between the two flanges and also LIMITS the maximum amount of force that can be applied between the two flanges, and it is only this force that is created BY the fasteners.

Further, the pressure temperature and chemistry of the FLUID defines what gasket will be needed, and thus, what specification is proper for that particular pipe.

So the original poster is not only asking the wrong question, but he or she is asking for the wrong answer to that wrong question.

 

[MikeHalloran]

For glass pipe, the correct torque is about 80 pct of what it was before you heard the 'crack' noise.



Mike Halloran
Pembroke Pines, FL, USA

 

[MJCronin]

racook...

OK then....I agree on your theoretical points.... It would be nice to evealuate each flange based on the specific gasket selected, the specific pressures and temperatures of the system.....etc...etc

However, on many metalic piping systems, the integrity of the flange is not an issue. The proper torque necessary for the fasteners depends only on the type of flange (Class) and materials of the fasteners.

Rules of thumb are necessary in the real world....

But, racook ...Which fasteners and what torque is appropriate for use on Cast Iron 125# Flanges ?

Can you give us a source ?

-MJC

 

[racookpe1978]

No.

Again, I return to the requirement: Find the torque required BY the specific gasket manufacturer FOR the specific lubrication used BY the specific crew tightening the flange.

So - >
Determine the original poster's gasket choice for his/her chemical or fluid and pressure and temperature.
Look up that gasket maker's web page (I often use Garlock or Flexatallic with lubricated studs or bolts, so those are the only sources "I" look up.
I DON'T use ANY other sources.
II DON'T use any generic mechanical or bolt torque chart or flange chart from ANYWHERE but the gasket maker.
Every now and then, there will be a drawing with torques, but that's very, very rare in my company. (Your mileage may vary.)
Then I pick the pipe size and pressure (flange rating) and print it out and pass THAT specific info AND that specific bolt tightening pattern (cross-tightening arrangement and number of bolts and number of torquing passes) to the crew and foreman.
Then, during assembly, I check what is being done, what torque wrench and calibration and method is used, and how the foreman is controlling the star pattern disciple that is needed.
.