UG-36(g) vs. B16.9 - Eccentric Reducer Section

[FoxRox]

I want to use a 48" X 36" eccentric reducer as part of a pressure vessel. The reducer conforms to ASME B16.9 (according to vendor; I don't have it), but it does not appear to be in compliance with Section VIII Div 1 UG-36(g)(2). The α on this reducer is well over 30 degrees.

I attached a screenshot of what my plan was.

Has anyone run into this before? I know Section VIII has the final say, but why is it more stringent than the B16.9 spec? Can I make this work? If not, any suggestions for an alternative?

Thanks!

 

[SnTMan]

FoxRox, according to my (admittedly older - 2003) copy of B16.9, there is no 48 x 36 reducer, your vendor is apparently incorrect in stating it meets B16.9.

In that case the reducer may not be used under UG-44. It must meet the rules for reducer sections in UG-36(e) and (f) if applicable.

Regards,

Mike

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[FoxRox]

Mike,

Thank you for looking that up! To be more specific, the catalog I'm looking at designates that this reducer is "in accordance with B16.9. Special Fittings paragraph 4.4.2."

Does the 2003 version have that, or has it perhaps been added since then?

 

[JohnGP]

The 2003 edition has that, but marking requirements have been revised between that and my 2012 edition (still current)

[bold]4.4.2 Special Fittings[/bold]
That the fitting was manufactured in conformance with this Standard, except that dimensional requirements are as agreed between the purchaser and the manufacturer, is certified by a supplementary suffix to the material grade designation marking as follows:
(a) “S58” of ASTM A960 applies for fittings in accordance with ASTM A234, A403, and A420.
(b) “S8” applies for fittings in accordance with ASTM A815.
(c) “SPLD” applies for fittings in accordance with ASTM B361, B363, and B366.

[bold]Section 4[/bold] is all about marking requirements, and with the supplementary designations called up in para 4.4.2 for special fittings. You would need to confirm that the fitting would indeed be marked in accordance with the standard.

 

[SnTMan]

FoxRox, I had not read Sec 4. Having done so, I am changing my opinion. If the fitting is marked as required, it seems it could be used under UG-44.

Regards,

Mike


The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[FoxRox]

Thanks for the help! Much appreciated!