Flange rotation

Hi

What's flange rotation and how can it be avoided?

Could any body please help me with this?

Thanks

anil1729,

why you don't use a swivel ring flange?

Ok I'm going to take a stab at this question! …"Flange Rotation" ...The problem of not getting the flanges on the pipe spool so that the bolt holes don't straddle the centerline squarely!!? This is caused by poor fit-up by the welder! They do a thing called "two holeing it" ...where they position the pipe spool in the correct plane then position the flange …with this two hole method ...inserting two tapered pins in the bolts holes and placing a level on the pins. Theoretically then the bubble in the level is centered ...so are the 2 bolt holes along the flange centerline. Problem is that the whole spool piece needs to be positioned correctly. Not such a hard problem in a shop, but alittle harder to do out in the field. So you could end up with the flange bolt holes not fully lining up with the equipment bolt holes.
SO ...Did I get close??

SO ...Did I get close??

________________________

No. The explaination is way off the mark. To quote krishna and prasad from an article they have written.

" Angular rotation of a flange under the influence of bolt pre-load and reaction forces is called flange rotation."

I would not say '" way off the mark". Thats why JOP asked for more information in an earlier post. Just asking what flange rotation is not specific enough cas people all over the world can have different terms to describe things. Asking the question describing the context would make things clear.

Regards