Flange connections, Petrochemical industry 1

[whizzkas]

Can anyone tell me why washers are never used with the stud bolts of flange connections?

 

[unclesyd]

Flat washers.
99.9999+% of the time there is no need for washers as they tend to complicate the makeup of a flanged joint.

They tend to be used on corrupted nut landing areas on the flange that need to refaced.

They are never the right size and thickness for proper bolting.

The reasons for not using them are numerous.

Last but not least they fall from great heights and hit people; ME

 

[FIF99]

Hi,

Agree for steel flanges. For Plastic Flange connections washers are often required in order to protect the flange blades. For GRE piping systems we do specify washers.

Success,

Regards
FKE

 

[tothepoint]

One HUGE reason for using through hardened (repeat, through hardened) washers is the consistent, smooth, high compressive load bearing surface they provide for the nut turning against it. If you're using a torque wrench and computing assembly torque values, the nut factor value will be much more consistent with a controlled, smooth nut bearing surface. Have you seen the condition of the nut bearing surfaces on most flanges out in the field? Pretty rough.