Different Raised Face Diameter 1

[patchlam]

Hi all,

Good day to all the engineers,

May I know that whether are we allowed to connect 2 raised face flanges with different diameters of hub or raised face diameter? For example, the nominal pipe size is 2", the two diameters of the raised face are 84 mm and 96 mm respectively.

If yes, what are the types of gasket that I should use in this case and how should I determine the dimension of the gasket? Is it based on the larger or smaller diameter of the raised face?

Thank you for your time!

 

[nickelkid]

What is the code, standards, design criteria to be met?

If they are B16.5 flanges (rating?) they appear to be out of spec.

 

[LittleInch]

The only thing that comes close to matching your dimensions are 2" ANSI 16.5 flanges with different size tongues ( as in tongue and groove) which are not the same as a raised face. or one RF and one "tongue".

Have you got more details ( flange code, pressure rating, dimensions or a photo).

In general dissimilar anything is a bad idea when it comes to flanges so I would say not allowed and get two the same to the same code.

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

 

[patchlam]

Hi all, I just found out my mistake. I guess there is difference between diameter of the hub and diameter of the raised face for the flanges. The raised face diameters for both flanges should be taken as 92 mm at 2". Anyway, may I understand why the raised face diameter is not listed or mentioned inside ASME B16.5?

 

[bimr]

The raised face diameter is listed in ASME B16.5:

http://www.engineersedge.com/hardware/flange-ansi-standard1.htm

 

[LittleInch]

Of course it is - see figure 6 and table 4 of ASME B 16.5

It is the same diameter for all pressure classes so isn't dimensioned in the other dimensions for different pressure classes.

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