Can we use fabricated plate flange(Top & Body flange) in U-Stamp vessel.....URGENT pls [ponder] 1

[ramesh349]

Dear All,

Greetings of the day,

Currently i am working with an U-Stamp vessel. we are in starting stage of design. We received the drawing with plate fabricated flange.
I am facing much difficult to find proper answer for his case, because ASME do not dealing with any plate type flanges excepr as in UG-34. if i am using UG-34, plate thickness going up. Also, this type of flanges are not listed in App-2 table.

Please clarify me, this flanges can i use in U-Stamp vessel. if yes or no, please share your views and code references for strong understanding.

Vessel having I.D 1800 mm and SS - MoC. Schematic drawing attached for your references.


Thanks in advance,

Regards,
Ramesh Kumar

 

[marty007]

Yes, you can use plate flanges.

The lower body flange should be designed per App.2 rules. The most common details using plate material would be Fig.2-4 details: (3a), (4b), (8), (9), (11). Important note regarding plate material, you cannot use plate for hubbed flanges unless additional requirements are met (see paragraph 2-2(d)(2)).

The blind flange with nozzles should be designed per UG-34. The relevant figure is Fig. UG-34(j) or UG-34(k) depending on gasket material used.

 

[ramesh349]

Hi marty007,

Thank you for your response,

i am little bit confused about the gasket type & material. Can i use a spiral wound non standard gasket in this case. Because the design pressure is 3.5 Bar.

Also, what are the additional requirements i have to consider for both design and construction. Please share your views.

Material is SA240 Type 316L
Flange ID:1800mm
Design Pressure: 3.5 bar

 

[marty007]

Yes, you can use any gasket you want. When you go through the formulas of App.2, you'll find two important design factors for the gasket, these are the m&y factors. ASME VIII-1 provides Table 2-5.1, which gives a list of some typical m&y factors. Note however the general note at the bottom of this table, which states that these values are suggested and non-mandatory. It is common practice instead to look up the literature of the commercial gasket suppliers to find m&y values for the specific gasket material being used.

One other detail to be careful about is for if you use Figure 2-4 detail (11). Note the requirements from UG-93(d)(3), which require additional inspection with dye penn or mag particle testing of the flat plate surfaces.

Other than that, there's nothing else that really jumps out at me for additional requirements, you just need to read the relevant sections and work your way through the calcs.

 

[dhengr]

Ramesh349:
Does your sketch show a flat plate for the top of the vessel? A 6' dia. flat plate, with a 50psi working pressure is going to take one mighty thick pl. or some serious pl. stiffening, or it will twist the flange right off the vessel, won’t it? A flat pl. will have a very high deflected shape and a large slope out at the vessel shell, and/or it will induce a significant fixed end moment on the flange and tank shell. I’d use the same semi-elliptical head as you show on the lower end of the vessel, and an added lower edge flange, for the top of the vessel.