What is a rotating flange?

A swivel ring flange is a two piece constructed flange used extensively for offshore pipelines and offshore industry applications. In a swivel ring flange, the rotating ring is held on by the welding hub that is in turn secured by a retaining ring. A swivel ring flange is also known as a swivel flange.

What are the different flange standards?

The most common flanges pressure classes are #150, #300, #600, #900, #1500, #2500 and #3000 according to ASME designation. To other standards, as DIN, pressure classes are defined by the acronym PN, as for example, PN10, PN16, PN20, PN25, PN40, PN50, PN100, PN150, PN250 or PN420.

What is the tolerance for flange misalignment?

The mating flange at the other end of the spool must now be within the tolerances of 335.1 (c) (1)to avoid detrimental strain as noted in 335.1 (a). If it was a 1 ft long spool piece the flange gasket faces cannot be misaligned more than 1/16″. A 50 ft long spool piece can have up to a bit over 3″ misalignment.

How big can a flange gasket be misaligned?

If it was a 1 ft long spool piece the flange gasket faces cannot be misaligned more than 1/16″. A 50 ft long spool piece can have up to a bit over 3″ misalignment. By moving the pipe across or up/down 3″ over 50 ft the committee has deemed unacceptable strain has not been induced in the joint.

Can a 6 ” flange be misaligned to a 12 ” pipe?

Now in strict measurement terms yes, the allowed misalignment for a 6″ flange is 1/32″, but in angle terms it is the same as a 12″ dimension with 1/16″. Length is irrelevant o how you fit up the flange to be 90 degrees to the axis of the pipe. A simple jig should fix this in place surely? Also: If you get a response it’s polite to respond to it.

Is the alignment the same for all flanges?

The alignment is basically an angle which applies to all flanges. Now in strict measurement terms yes, the allowed misalignment for a 6″ flange is 1/32″, but in angle terms it is the same as a 12″ dimension with 1/16″. Length is irrelevant o how you fit up the flange to be 90 degrees to the axis of the pipe.