ASME VIII vs TGL Pressure Vessel Strengths 1

[CSGWB]

I am currently reviewing the design of a pressure vessel designed in Germany in 1987 to TGL in order to comfirm it's adequacy against the requirements of ASME VIII. I am finding that the wall thickness required under ASME VIII for the nominated design pressure is greater than that used in the construction of the vessel.

Does anyone know how the maximum allowable tensile strength for carbon steel materials (A283 GrC) was determined in the applicable TLG (in 1987)?

Regards

Craig

 

[prex]

Don't know that standard, but it is well known that at low temperatures the european allowables are higher than the american ones, mainly because of a less stringent limit based onto ultimate strength (the limit based onto yield being the same). The difference was quite important a few years ago, when american (ASME) allowables have been revised (increased) to approach the european ones.

prex

http://www.xcalcs.com

Online tools for structural design

 

[CSGWB]

Prex

Can you tell me what the european (particularly German) ultimate strength factor would have been when this vessel was designed (87)? I know ASME back then was UTS/4 (now UTS/3.5).

Craig

 

[prex]

That factor is presently 2.4 for common ferritic steels (EN13445).
I have a copy of AD-Merkbl. dating back to 1988 (!): don't know very well this standard, but I understand that the allowable stress is obtained by simply dividing by 1.5 the following example values:
St-37 thk.up to 16 mm temp.between 50 and 100°C: 187 Mpa
St-44 as above: 220 MPa
St-52 as above: 254 MPa

prex

http://www.xcalcs.com

Online tools for structural design

 

[CSGWB]

Prex,

Looks like I will have to dig a bit deeper and see if I can locate the original calculations to get to the bottom of this.

Thank you for your assistance.

Craig

 

[ijzer]

TGL was used in former East-Germany. From what I remember the safety factors are Rm/3 and Re/1.5