SECT. VIII, DIV.1, APPENDIX 2, ROLLED RING HUBLESS, FIG. 2-4 SKETCH (8)

[bayardwv]

I have a question regarding whether or not a Flanges made from 3/4" Plate rolled into a Ring, used in a design rated for 500 PSI @ 200°F can be designed as a LOOSE Flange.

Years ago we were directed to design all flanges used on designs with pressures greater than 300 PSI as an Optional Integral.
The Engineering managers reason for this was that in App. 2-4(c) it states that Optional Type Flanges can be calculated as loose type flange provided several values aren't exceeded. One of these values is that P not exceed 300 PSI.

I have always disagreed with their blanket statement that all flanges over 300 PSI must be Integral, because no where in 2-4 (a) Loose Type Flanges, does it state that there are any restrictions. Am I correct in stating that Flanges designed for Pressures greater than 300 PSI can be designed as LOOSE TYPE FLANGE?

What would the benefit be of calculating an Optional Integral type flange as a loose flange, other than simplifying the calculation.

Attached a sketch of our flange design using Bent Clips to retain the Bolts.

Regards,
Julie

[URL unfurl="true"]https://res.cloudinary.com/engineering-com/image/upload/v1565793347/tips/8-14-2019_10-16-55_AM_gys2ic.pdf[/url]

 

[SnTMan]

I have a question regarding whether or not a Flanges made from 3/4" Plate rolled into a Ring, used in a design rated for 500 PSI @ 200°F can be designed as a LOOSE Flange.

Am I correct in stating that Flanges designed for Pressures greater than 300 PSI can be designed as LOOSE TYPE FLANGE?

Yes, there are no pressure / temperature restrictions on loose type flanges. Also, loose flanges may be either burned from plate, or rolled and welded.

What would the benefit be of calculating an Optional Integral type flange as a loose flange, other than simplifying the calculation. v

Probably none, I'd expect the loose flange to be thicker than an integral type.

Attached a sketch of our flange design using Bent Clips to retain the Bolts.

Sorry, can't make much of that.

Regards,

Mike

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[balamurugan02]

Gents, I also have some doubt on a similar subject. Can we fabricate flanges (without hub, for e.g. Fig 2-2 (1a)) from machined plates. I understand that the limitation of 2-2 (d) doesn't apply to flanges without hub. But for some metallurgical reason I was told to fabricate flanges from forging and not from plate (unless the plate is rolled and welded as a ring). I was told that the mill hot rolled direction / axis of plate should be circumferential to the axis of flange. Similarly I was advised to fabricate shell (cylinders) having the plate's 'hot rolled axis' in circumference rather than in parallel to the longitudinal axis of vessel. I guess, this is must be discussed earlier but I couldn't find any solid reference to this.