4500# Flanges - ASME B16.5 & ASME B16.34 1

[dz84]

I have an inquiry for a flanged control valve in Inconel 625 for service in 250 bar, 550°C. This is a group 3.8 material and I verified that a 4500# flange would meet the system requirements. However, I cannot answer the customers question as to why the 4500# flange is listed in ASME B16.34 but not 16.5. Can anyone tell me? They are hesitant to move forward with this in case the flange/valve is not ASME approved. Any insight on this flange would be greatly appreciated. Thanks!

 

[SPDL310]

Max flange rating in B16.5 is 2500#. See the following link.

 

[LittleInch]

If you look in ASME B 16.34, section 2.1.1 b) it states "Class 4500 applies only to welding-end valves"

There is therefore no flange #4500 ( 775 bar! @ 50C) listed, in 16.34, only a rated valve able to withstand that pressure. If you want to flange it then depending on what our actual design pressure is you probably need an API 10000 or 15000 flange or some other flange system (norsok) whose flanges are rated for this rather large pressure welded to the end, providing your end dimensions match up.

It's not clear if there ever was a #4500 flange, but there isn't one now....

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[dz84]

Thank you both! I was way in the weeds on this one and just needed to take a step back and look at this.

We are working with the customer to see what other kinds of fittings/ends they are using throughout the system. I have yet to work with API flanges but perhaps that would be a suitable solution for them. Thank you again.

 

[SPDL310]

API 6A Max temp class is Y where operating temperature is 650F/340C. I don't think your pressure and temp range will allow you to find a suitable API flange.

 

[SPDL310]

I will clarify my earlier post before someone else does. There is no clear outline for de-rating a flange past 650F in API 6A annex G. This doe not stop manufactures from doings so, but the item being sold could not bear an API 6A monogram at the temperature and pressure rating the OP is asking for. It is possible that higher pressure flange geometry (10K or 15K) could be used for his purpose but it would require the calculation package to back it up. With that being said the OP may have trouble finding a manufacturer to produce the item he is asking for.

 

[LittleInch]

Ummm, I suppose that is rather hot and at a significant pressure.

I would be welding that.....

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[MickMc]

Take a look at Hub Connectors and Compact Flanges e.g. Techlok, Grayloc & Galperti as these are frequently used offshore and increasingly onshore in high pressure systems with added weight saving benefits and designed to ASME VIII. Most major valve manufacturers will supply with hub/compact flange ends with permission of selected hub/compact flange manufacturer.