urgent need of thicknesses of 24" sch 40 tee

[huguette]

URGENT
We erect a lot of "standard" tees in our HRSG but never received detailed thicknesses. We urgently need the various thickness of the 24" sch 40 tee (fitting) to evaluate by ourself the conformity of our tees.
thanks

 

[dbaird]

I don't know if this helps you but check:

http://www.pipingdesigners.com/codes & standards/Codes & Standards - 37.htm

David Baird

Sr Controls Designer
EET degree.
Journeyman Electrician.

 

[jte]

Sorry, but there is no standard thickness. The only standard thickness would be at the weld bevels. Besides that, its pretty much up to the manufacturer to meet the pressure retaining requirements, but they are free to vary the thickness as they see fit so long as the proof tests pan out.

Related threads:
thread292-127371
thread378-122201

jt

 

[MortenA]

This is a little risky since its not my area of expertise beeing a chemical engineer but: The "Trouvay & Cauvin" (usually referred to as the pipers bible where i come from) list the wall thickness for a 24" ANSI B 16-91978 straigt Tee sch 40 to be 17.44 mm (that the weld bevels not "everywhere").

Best regards

Morten

 

[huguette]

thanks for your answers, but I was not precise: I want to know the true thicknesses along a tee, not the thickness of the straight acc. pipe.
the thicknesses can be up to 1.5 the pipe thickness, and it is a manugacturer knowledge, but if it is a "standard" tee, I think that it will not be a great difference between manufacturers.
the thicker parts have to be the 45 degree of the neck and after this the meridian line.
NEED URGENTLY
THANKS

 

[TBP]

I think you'll need to get that particular information from individual manufacturers.

 

[rconner]

I believe reinforcements for various fabricated pipeline intersection fabrications (tees, crosses, wyes etc.) are discussed in many references and manuals. While I'm not familiar with all other fields, conventional reinforcements for steel water pipe fabrications (that are wrapper plates, crotch plates etc., depending on ratios of sizes, thicknesses, and pressure conditions etc. -- the wall material removed from the parent pipe for the intersection is of course no longer there to help carry the loads) are discussed in AWWA Manual M11. I suspect procedures in perhaps some multiple fields at least in the USA are probably also outgrowths of earlier section of Boiler and Pressure vessel code.

 

[TGS4]

As jte and TBP stated, there are no standard thicknesses. You will need to contact your manufacturer. Chances are pretty good that even they would have to take several spot UT-thickness measurements to give you the data that you are looking for. However, based on my experience of trying to get similar data from olet manufacturers, all I can say is "good luck".

Since you're looking for "standard" measurements to compare with "as-received" pieces, I think that for the most part you're not going to find that information.

I'll ask one question of you - why do you need this information? Do you have tees failing on you? Are the failures a direct cause of insufficient thickness? This is starting to smell like an exercise dreamed up by a pointy-haired boss.

 

[huguette]

Thanks to all these friends that answered me about this surprising problem, that nobody can give me a detailed drawing of a major fitting that obviously will be in our systems the first element that will creep !!!!! The fitting have been bought by a major contractor that work with various manufacturers ( all correctly certified )we receive the according proof test of the test fitting which is not our tee but according to b16.9 is in the size range (qualify similarly proportionned fitting ).
thanks, I learn a lot
Specially to JTE that send me to related threads ( I am not alone...and the JOHNBREEN answer was very interresting) and to the "Good luck" of TGS4.

friendly
huguette

 

[rconner]

It is interesting to see the apparent confusion created here. I think this is possibly due to the terminology used. I believe "Schedule" used to be primarily used to sort of define the thickness based on size of straight pipe (per a table or "schedule" etc.) As was stated previously in this thread, a 24" Schedule 40 steel pipe was thus shown as 0.687"(17.4mm) in thickness.
I know e.g. also in the very old Crane manuals, outlet "nozzles" were either "Standard" (fabricated with straight pipe, no reinforcement)) or "Reinforced" in some fashion (pads, collars, wrapper plates ,etc. as required by the service pressure) Forged steel fittings such as tees then appeared referred to not by schedule, but by rating in "Pound class" etc. (these would indeed have variable thickness depending on configuration/working pressure etc.)
While I don't doubt it is now done, it just seems strange to refer to a tee fitting by "schedule", particularly if the pressure conditions require that a standard schedule thickness is not adequate!

 

[TBP]

The required pipe wall thickness is calculated, then the fittings are selected off that. I've never seen any other way of doing it. If you need sch 80 pipe, then the appropriate butt weld fittings are sch 80. The fittings have a better rating than the pipe they're being welded to. There are tables for things like forged steel screwed fittings, but again, based off knowing what sch pipe is required. I don't recall ever seeing a calculation for a fitting being done in the course of designing a piping system.

 

[JohnBreen]

Hello,

jte is correct (please look at the references). VERY LITTLE GEOMETRY IS "STANDARDIZED" BY THE ANSI B-16.9 STANDARD FOR WELDING FITTINGS. Also, many manufacturers consider thickness information to be "proprietary" (don't bother asking them). If any two manufacturer's fittings have the same thickness at the same relative location around the fitting it is purely by coincidence.

Actually, if you compare a fitting manufactured to ANSI B16.9 to the ASME "area replacement" rules for fabricated branch connections you will see that the fittings will not comply - yes, they are stronger but due to due to material (grain) continuity (and the radius at the "crotch"). One thing is certain and that is that the fitting's wall thickness will be greater that the (same schedule) matching pipe at all locations other than the weld line. How much thicker? It depends upon the manufacturer. Perhaps more importantly, the general shape of the TEE fitting will differ greatly from manufacturer to manufacturer - some will be very "cylinder-to-cylinder" in shape, some will be "barrel shaped" and some will have pronounce "spherical cheeks". The radii at the crotch will also vary greatly and the thickness at the crotch will also vary.

Fittings are required by ANSI B16.9 to be able to pass a burst test. They are made so that if you weld a fitting (i.e., TEE, elbow,.....) between two pieces of straight pipe and pressurize the weldment to destruction, the straight pipe will fail before the fitting.

So, what is the wall thickness of a "Standard" ANSI B16.9, schedule 40, TEE? First of all it varies around the fitting and also only the UT thickness gage knows for sure.

Regards, John.

 

[krb]

Weldbend has some dimensions for tees on their website, but based on your question i am not sure if this is what you need or not.

http://www.weldbend.com/Fittings/Straight Tees/STDTEE.htm

KB

 

[jte]

krb-

Yup, they don't mention that the "T" thickness dimension is wall thickness at the ends of the tee until you jump to their tolerances page and look at Note 3:

http://www.weldbend.com/Technical Data/Dimensional Tolerances for Fittings/tolelbtee.htm

The thickness is not uniform throughout the tee.

jt