Type B fittings

Here you can post your question about ROHR2.
Antworten
aditya0608
Beiträge: 26
Registriert: Mi 28. Mär 2012, 08:15

Type B fittings

Beitrag von aditya0608 » Di 9. Apr 2019, 06:59

Hello Rohr2 Users,

I have fittings of Type B according to DIN-10253-2 in a calculation. Thickness of these fitting will not be same as pipe.
For Ex; EN 10217-5 for Pipe 800 DN =813mmx12.5mm
for elbow EN10253-2 Type B, T2R3 Thickness of this elbow is 15.6 mm in standard.

But i cant define thickness as per Standard in Pipe definitions. User defined thickness need to be entered for elbow/bend.
Please let me know whether approach is correct or Rohr2 has some kind of database to fetch thickness information automatically.

Regards
Sie haben keine ausreichende Berechtigung, um die Dateianhänge dieses Beitrags anzusehen.
With Regards
Aditya Singh

Benutzeravatar
rohr2admin
Administrator
Beiträge: 493
Registriert: Di 13. Sep 2011, 14:03

Re: Type B fittings

Beitrag von rohr2admin » Mi 10. Apr 2019, 14:33

Hi

The fittings of Type B in EN10253-2 are designed to withstand the same pressure as the connecting pipe with the same dimensions. The connecting wall thickness is called "T".
Bend_EN10253-2_part_B_sketch.PNG
The wall thickness intra-dos (T_int) must be bigger so that the same internal pressure can be supported.
Bend_EN10253-2_part_B.PNG
For the flexibility characteristics (and stress intensification factors) the relevant parameter is not the intra-dos thickness but the average thickness.
Historically (in the DIN) there was also a T_ext which was smaller than T so that in total the average wall-thickness may be the same as for the bend with a constant wall thickness T. Therefore it was correct to use T as wallthickness in the stress calculation. With the EN10253-2 the extra-dos thickness is specified as "at minimum equivalent to T". On top of wasting material this will also lead to an average thickness in the bend that is higher and this will reduce the flexibility of the bends. The impact on the stress-analysis is the following:
  • The piping is less flexible and therefore support and nozzle loads from thermal expansion are under-estimated
  • Stresses in the Bends are more or less correct as the reduced flexibility is compensated by more material and therefore reduced stresses
So in short: For piping systems where nozzle loads from thermal expansion are not relevant, you can just continue to use T as wallthickness for the Tees of type B. When nozzle loads are critical you should calculate an average wallthickness, such as T= (T_ext+T_int)/2=(T+T_int)/2.
This would give you more realistic results. We are preparing to introduce the idea in the EN13480-3 in table H1:
The relevant wall thickness of bends should be taken at the crown. If unspecified, the average wall thickness of intrados and extrados may be used. For elbows, the wall thickness series from EN 10253 may be used.
Best regards

Rohr2 Support
Sie haben keine ausreichende Berechtigung, um die Dateianhänge dieses Beitrags anzusehen.

aditya0608
Beiträge: 26
Registriert: Mi 28. Mär 2012, 08:15

Re: Type B fittings

Beitrag von aditya0608 » Fr 3. Mai 2019, 14:05

Thanks a lot.

regards
Aditya
With Regards
Aditya Singh

Antworten

Wer ist online?

Mitglieder in diesem Forum: 0 Mitglieder und 0 Gäste