Verifiction of flanged valve body design 2

[660301]

Dear all,

I am designing a flanged valve body for ANSI 1500 (3750 psi). The details of the body are as per B16.34; the flanges (RF) are as per B16.5. They will be a complete piece of a casting.

In order to confirm the design, I may have to do some calculations for registration(ex. for a CRN number). Could anybody tell me what kind of calculations are required? for example should I re-confirm/re-calculate the flange as per ASME Bolier and Pressure Vessel Code VIII Section I appedix 2?

I found for many cases B16.5 flanges may not pass ASME Bolier and Pressure Vessel Code VIII Section I appedix 2. Could anybody kindly comment on this?

Also the Bonnet is bolted to the body. Portion of the Bonnet cavity is under pressure (3750psi). Should I check the Bonnet wall thickness by using ASME Bolier and Pressure Vessel Code VIII Section I? However the section I is good for pressure under 3000 psi, what will be used for the calculation?

Thanks a lot.
Adam

 

[proinwv2]

You are probably correct in that some of the B16.5 flanges would not pass VIII Div 1 App.2.

However, the code accepts B16.5 flanges but to use that logic, then you would have to meet the specs of B16.5 for that portion of your design. You may not meet the material specs, read them carefully. (I don't remember if cast materials qualify.) If you can use that logic go that way. Then you are home free.

Else, I have done CRN work for a product that is built with standard B16.5 flanges, but modified. Due to the pressure and temp ratings of this product, and the low y value gaskets, the product readily passes App.2.

In any case if you can't match B16.5 give App. 2 a try also.

As to the bonnet, to start with a valve is not a Sec. VIII pressure vessel so you are already in a different area. You are qualifying to the "intent" of it.

I haven't read B16.34 recently, but what will that do for you? By the way, if you can qualify the flange at that pressure as a B16.5 then you could argue that logic for the bonnet flange and see what the Canadians think of it.


Paul

http://www.ostand.com

 

[660301]

Hello Paul,
Thanks a lot for your useful information. I have just finished the design.
The casting material is LCC that is listed in B16.5. The Body was designed as per B16.34, and the flanges on the Body were designed as per B16.5, actually they look even stronger than the standard ones based on the geometric information. Calculational confirmation for the connection between Body and Bonnet was also done.
Hope this will be OK.
Adam

 

[proinwv2]

I assume that when you refer to the flanges on the body to B16.5 you are referring to the inlet and outlet flanges.

If so, then you are correct. Sounds good.



Paul

http://www.ostand.com

 

[660301]

Hi, Paul,
Thanks. Yes, you are right, the flanges mentioned are the inlet and outlet flanges. They are in the horizontal direction, located left and right sides of the Body and for the connection to the pipeline.
The connection between Bonnet and the Body is through 8 bolts, this is in the vertical direction and located in the top-middle portion of the Body. There are 8 tapped holes on the Body for such purpose.
Merry Christams.
Adam

 

[proinwv2]

OK and best to you.

Paul

http://www.ostand.com