Pavan Kumar
Chemical
- Aug 27, 2019
- 375
Hi All,
I have assigned to check the design pressure of a Welded Carbon Steel Pipe (EN 10217-2 Gr P235GH or EN 1.0345) for DN 400 (OD= 406.4mm) line size with a wall thickness of 11mm. The fluid is Saturated Steam at 16 bar(g) ( TSat= 204.345 Deg C). I went through EN 13480 Part -3 and got the formula for Pipe Wall Thickness without any allowances or tolerances.
e =( pc * Do ) / (2* f*z+pc) ------> From EN 13480-3 : 2002+A4
where,
e = pipe minimum wall thickness, mm
pc - calculation pressure or Design Pressure, N/mm2
Do - Pipe OD ,mm
f - Design stress or allowable stress, N/mm2
z - joint coefficient ( z=1 for seamless pipes)
Going through EN13480-3, I see that f needs to calculated as the lower of Time Independent and Time Dependent stress. This calls for determining values such ReH,t, Rp,0.2,t, Rm etc. I need help on how to get these values. Also I need help to determine the Time dependent stress fCR = SRT,t/ SFCR. How do I get SRT, t?
Any guidance will be very helpful to me.
Thanks and Regards,
Pavan Kumar
I have assigned to check the design pressure of a Welded Carbon Steel Pipe (EN 10217-2 Gr P235GH or EN 1.0345) for DN 400 (OD= 406.4mm) line size with a wall thickness of 11mm. The fluid is Saturated Steam at 16 bar(g) ( TSat= 204.345 Deg C). I went through EN 13480 Part -3 and got the formula for Pipe Wall Thickness without any allowances or tolerances.
e =( pc * Do ) / (2* f*z+pc) ------> From EN 13480-3 : 2002+A4
where,
e = pipe minimum wall thickness, mm
pc - calculation pressure or Design Pressure, N/mm2
Do - Pipe OD ,mm
f - Design stress or allowable stress, N/mm2
z - joint coefficient ( z=1 for seamless pipes)
Going through EN13480-3, I see that f needs to calculated as the lower of Time Independent and Time Dependent stress. This calls for determining values such ReH,t, Rp,0.2,t, Rm etc. I need help on how to get these values. Also I need help to determine the Time dependent stress fCR = SRT,t/ SFCR. How do I get SRT, t?
Any guidance will be very helpful to me.
Thanks and Regards,
Pavan Kumar
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