ASME B16.9 reducing tee - 3x1 not listed!

[XL83NL]

Guys, we've just experienced the following in a current project. For some reason,
which isnt relevant for the subject of discussion, isometrics contained ASME B16.9 3x1 reducing tee's.
When I look in pipe&fitting catalogues of our suppliers, (nearly) all of them list ASME B16.9 3x1 reducing tee's as what they can supply by standard.
B16.9:2007 doesnt list 3x1 reducing tee's, so they're not (per standard) ASME listed fittings, and thus (per standard) approved for B31.3 piping systems.
Ive also just seen an MTR for an A234 WPB 3x1 sch 40 tee, and it says its acc B16.9 (yes, I know, MTR's get frauded all the time, especially Chinese and so forth).

How come all/most suppliers list B16.9 3x1 tee's as standard, even though they're not?
One obvious explanation is market demand, but what else is there?
Ive got the feeling there's another reason, which I dont know of.

What's also funny to see is that the standard ASME fittings catalogue of our
drafting suite (Autodesk Plant 3D) recognizes 3x1 reducing tee's as a B16.9 fitting.

 

[giampi]

3*1 reducing tees can be considered incuded in ASME B16.9 taking into account paragraph 4.4.2 of that code "special fittings"

 

[XL83NL]

Thanks for the reply giampi.

I agree with you on that para, I noticed it. However, doesnt it then require a certain suffix on the MTR?
The MTR I have didnt had any ..

Second, wouldnt that paragraph give any mill a permit or license to just make any desired
fitting with dimensions not listed in ASME B16.9 (e.g. say 8"x1/2"), and still mark them as
ASME B16.9 fittings, without any additional info?

Doesnt sound really plausible, even though para 4.4.2 is in there ..

 

[giampi]

Yes, dimension not listed can be accepted if agreed between manufacturer and purchaser,if they are not by pipe fabrication and their design respect all the applicable requirements of the Standard. See paragraph 1.2 of ANSI. But in the market is very difficult found fittings with sizes not listed in the Standard. For experience, my suggestion is to use always only standard sizes.Often, to got one overall order, a Vendor can produce special fittings, but if during construction you have shortage of 1 or 2 pieces, no Vendor you can find to supply them.

Regard the MTR, yes a suffix S9 should be added, but if the Vendor is qualified and well known, could be superseeded.

 

[XL83NL]

Still find it strange that we, as a purchaser, didnt directly tell the mill (but accidently ordered) a special size fitting, and just got it like that.
I mean, if we told a mill to do it, okay ... also, strange there's nothing extra on the MTR (no suffix).

And from all the above written, I can now conclude that A LOT of material vendors supply standard 'ANSI B16.9' fittings (by means of their catalogues), while these fittings arent really standard ASME B16.9 listed.
They just make them up (prolly due to market demand)
Because of that market supply, CAD companies like AutoDesk just put all these non-standard ASME B16.9 fittings in their catalogues as if they are standard ASME fittings.
Upside world :S .. might in the end cause ASME to update their catalogues because of these market supply/demand.
Makes the circle round. I think I now finally understand economics.