Special Processes

[Mike48]

As defined by QS9K in element 4.9, pg. 35, would torque be considered a special process?

 

[db]

Depends

Mike

Whether torque is considered a “special process” would depend greatly on what you mean. For example, if you are tightening a bolt to a specified torque, it can easily be verified using a torque gauge. If you are using a torque-to-yield bolt, where the bolt is stretched, neither a torque wrench or angle meter can be used. I would think that this could qualify as a “special process” because as far as I know there is no way to test this type of fastener without loosing it and starting over (which will damage the bolt)

I think this is correct, hopefully your question is covered by one of the two types.

 

[M Greenaway]

Torque in itself cannot be considered a special process as it is not a process, it is a physical characteristic.

The process of tightening something to a required torque is only a special process if you cannot validate the required torque has been achieved.

The use of a simple torque wrench will overcome this problem.

 

[gpainter]

To add to this ,if a customer requires a certain lbs of torque. then the wrench will need to be calibrated.

 

[M Greenaway]

gpainter

or the process qualified, i.e. established by test that a certain number of turns with a spanner produces the required torque (if the torque isnt that crtical - i.e. wheel nuts). In instances of a more precise torque then a claibrated torque wrench would be the ideal method.

You may also have a subsequent test that will confirm of the torque has been achived, i.e. hydrostatic pressure testing of a valve head assembly.