Widening bolt holes due to too large of gasket 3

[mechengr12]

Is it ok to widen bolt holes 1/8" too allow for a gasket to fit between flanges? Does this lead to uneven stress? I have a large 20" plus line with a metal gasket that is approximately 3/16" too wide to sit in between the bolts. I would like to widen all bolt holes slightly to seat the gasket in between the bolts. When we pulled the previous gasket it was noticed that the outside of the gasket had rolled some due to bolts being forcefully put in.

 

[racookpe1978]

20+ inch diameter high pressure pipe flange = $400.00+ dollars.

And you would ruin that machined flange to fit a 18.00 dollar gasket?

Get the right gasket.
Use the right bolts.
Use the right torque applied the right way at the right intervals.

 

[Tunalover]

You are letting external factors affect the design. If the wrong gasket comes in it's NOT a design problem. It is a crime against the engineering profession to change the design to accommodate a defective or errant part! If someone specified the wrong gasket then return that one (if you can) and get the right one.

I worked at a place one time (it was a LONG 3yrs) where they had no dimensional inspection equipment. If a design didn't fit the upper management poked the design engineers and told them to fix the problem. They would not pay for the parts to get fully dimensionally inspected by a third party nor did their ever-tight schedules allow the parts to be returned to get reinspected by the fabricator. Hence, the design engineers were stabbing in the dark and providing solutions that made the parts fit. This was the same place where the production line workers would publicly put down the designers if the parts didn't self-assemble when you threw them in the air! Like I said. It was a long 3yrs. They got bought by a big company and soon the doors were shuttered and people were told they no longer had jobs!



Tunalover

 

[DSB123]

If you widen the boltholes then the bolt load is applied in a different radial position therefore the bolt moment will increase on the Flange. How do you know you are not going to overstress the flange. Flanges are pressure components and are designed. Bodging the bolt holts to enable a wrongly sized gasket to fit is not the way to go!! As people have said get a correctly dimensioned gasket. If you don't and the flange assembly fails how are you going to defend your "bodging" approach in a court of law? If anyone gets hurt they will lock you up and throw away the key!!!

 

[mechengr12]

Thanks. Issue has been closed.