Mr. Mandeep/Scott/Ray : 1] Why PVElite only allows designer to use Welded configuration on modelling of UG-34 Flat Head and excludes bolted configuration (j), (k) and (p)? PVElite considered UG-34 analysis on bolted flat head taken over by Appendix 2? 2] I have a case of 2" nozzle on a 26" blind (ASME B16.47 series A, 900#). I could not find provision like opening on blind covered by Table 7 on ASME B16.5. In your opinion, must I sacrifice the standard B16.47 pressure/temp. rating, conduct appendix 2 calc. on the "non standard" blind and accept the fact of failure ? [1" thicker and associated with higher cost/weight] Experience/opinion from forum members are welcome. Thank you!

Dear SK Tan,

In my opinion, in such cases, where you have to provide nozzles on the bolted blind flange,you can check & verify the nozzle opening reinforcement calculation on the standard blind by using UG 39 formulae as per ASME Sec. VIII Div.1 & can convince the client, in order to avoid Appendix 2 calculations for non standard blind flange.

However,PV Elite- COADE people should look into this & should include the UG-39 calculations ( opening reinforcement check on the flat heads) for such cases.

Regards
S.K.

When you make modifications to a std. ANSI flange then you have to perform the analysis to make sure it is code compliant. Cutting a hole in the blind flange to attach a nozzle is considered a modification. I would recommend analyzing that flange. Check with your AI first.

I know of a user who did not perform calculations on a std. blind flange with a nozzle, they build the vessel and delivered it. They eventually had to perform the flange calculations. They were saved by the fact the blind flange was little over-sized on the thickness.

You can check the opening in a bolted cover (blind flange) per UG-39(d) like this,

• In PVElite specify a flange,
• In the Additional Element Data indicate that you want to perform the flange calculations.
• On the Flange dialog, indicate that this is blind flange and specify the input or do a lookup.
• Come out of the Flange dialog, on the bottom of the main screen, check the box Evaluate Uniform Patterned Holes.
• For a single opening specify the diameter of the opening

To check the opening on Welded cover per UG-39(d) follow the above procedure except that you do not have perform the flange calculations.

We do that regularly. I wish too that PV Elite would do the UG39. I set up an excel file to do those calculations. It slows the process because you have to tweak your output to have that included too.
You are talking 2 inch nozzle (2"id) on a 26" blind flange. It is not a lot but it will thicken your flange. We go as high as 10" on a 50" blind flange. That becomes a special flange, so you have to do the calcs as the code requires you. Your AI will confirm that.

Dear Attila,

PVElite Performs the UG-39 calculation. That is what I stated in my post.

Please use this feature :-)

Yes, agree with what Mr Mandeep explained.

By choosing option to calculate the flange/blind, PVElite analyse blind as per UG-39 and flange as per Appendix-2.

The reports are quite identical. Earlier we thought blind report is Appendix-2 but actually it is UG-39. It is clear to us now.

Thanks!

iF I USE THIS

BLind Flange 20" SA350 LF2, i put it in pvelite.

The right temp (250 F) and the pressure 207 bar.

The Flange is okay, but wenn i check the box "evaluate uniform patterned holes?" the tichkness will increase directley with 80 mm. (3.14 inch). But i didnt put any diameter in box -> "Opening diameter d1, "

Also if i put 1(0.03 inch) mm or 254(10 inch) mm in the box it makes no different for the thickness?!?

Anybody

Hello, i fresh up a old topic with the next problem i got.

I got a 18" BLRF with a 14" Nozzle in it. I get to follow errors;

1. Warning : Flat head nozzle spacing error on flat head or flange (ligament)
2. Some nozzles do not satisfy the rules of UG-39.

I got PVElite & COADE.
In COADE i can't make a Blindflange with a hole. (Appendix-2) [Flange in COADE]
Large openings: Appendix-14 can't be used because that is for integral flange.[Large opening in COADE]

Somebody know how i can calculate the blind flange with hole?

1. Warning : Flat head nozzle spacing error on flat head or flange (ligament)

somebody? i got this erro

Hi Kinge,

The opening that you have is more than the head diameter / 2. So, that is why you are getting this warning. This is the limitation given in the ASME code.

In my opinion, the blind flange with the opening may be modeled as a a ring flange instead. As, the opening is so big.

Try it out and let us know how it works.

Hi Kinge,

Since your case involves a 14" nozzle on 18" BLRF, suggest to you to consider Reduction Flange concept allowed in ASME B16.5.

Get away from considering it as a blind which give you trouble to justify/calculate. Your case is like a pair of flanges with different size be integrated as one forged reduction flange.

No calculation is required as long as can satisfy requirement of Reduction Flange. The minimum hub diameter "X" values required on both 14" and 18" must be complied with during integration of them.

SK Tan

Hi boys,

UG-39 Nozzle Diameter and Distance to Edge Checks :

Nozzle | Nozzle | Head Dia. | Distance | Nozzle |
Description | dia. | /2 | from Edge | dia./4 |
| mm. | mm. | mm. | mm. |
N1/2 | 326.60 >>> 261.67 | 222.20 | 81.650 |


You can see that the nozzle dia. mm. 326.60 is to big comparison with Head dia. 261.67. SO I GET A ERROR
But the strange thing is that i use a 18" BLRF #300. And the outside diameter of the flange is 711.20. Wenn i change the dimensions in pvelite i have noticed that he calculates with "Gasket Reaction diameter G = Go-2*b"
It is not Head dia/2 but Gasket reaction diamter/2??
In Fig.UG-34(j)/(k) there is the 'd' displayed. Because it is a bolted flange you have to use this d?

Hello,

What is the procedure when we have nozzles in a Appendix-Y flanges.

regards,
Sanjay