Figuring out allowable strength reference (boiler pipe)

[Cessh]

Dear all,

I got to data from some old senior about boiler pipes data and used to calculate the minimum thickness,

Data Pipe No. 1

Pipe : Eco tube
Material : SA-210 C
OD Design: 2.01 inch
Thickness Design : 0.24 inch
Temperature Design: 617 Farenheit
Pressure Design : 2894.96 Psi
ALLOWABLE STRESS : 18303.80 Psi
Minimum Thickness (calculated per ASME Sec I PG 27.2.1) : 0.157 inch


Data Pipe No. 2

Pipe : Water Wall tube
Material : SA-210 C
OD Design: 2.50 inch
Thickness Design : 0.295 inch
Temperature Design: 781.34 Farenheit
Pressure Design : 2884.81 Psi
ALLOWABLE STRESS : 13038.92 Psi
Minimum Thickness (calculated per ASME Sec I PG 27.2.1) : 0.2614 inch

I understand the formula he used to get the minimum thickness, but can somebody explain how or from where did he get the maximum allowable stress?? Because i found that it's a different number than that from Table 1A ASME Sec II part D..

NB: because of certain circumstances he cannot be contacted anymore.

Best Regards,

 

[metengr]

Allowable stress values have changed over previous additions of the ASME B&PV Code. The allowable stress values are based on requirements found in Section II, Part D.

 

[Cessh]

Perhaps, but How to confirm that the allowable stress is taken from a previous edition of Section II Part D?

I have the 2007 version, the allowable stress is stated in Ksi with only two digits behind the decimal. But in the list of allowable stress i got from my senior it has 5 numbers behind the decimal (if converted to Ksi, as if it was the result of a calculation. That's is why i wanted to confirm. does someone has a version of Asme II D that matches the allowable stress numbers in the data above?

 

[GenB]

Kit looks that he interpolated temp vs stress. You may recalculate per straight Sect D numbers and will get same results. Stress seems like std 1990th Code.