ASME T limits: inch vs mm 1

[261073eam]

I have a colegues talk about which is the exact T limits in mm from inches.
The 5 mm Tlimits for WPS range is convert from 3/16", but as it is comment on nonmandatory appendix G, the value should be 4,75 mm. This value is in the same that API data.

In case of pipes thickness of 4,8 mm if my PQR was qualified with 11 mm, i am able to weld it if the WPS range is from "5" to 22 mm or not.

Thanks

 

[Duwe6]

4.8mm equals 5mm [no decimal places, rounded off per good engineering practices]. "Book Smart, Field Ignorant" folks will try to specify welds or evaluate WPS's in tenth's of mm's and thousandth's of inches.

ASME Section IX is written in 1/16's of an inch and integer mm's only. Interpolation to closer tolerances is rediculous and well beyond the intent of ASME. You can always tell the 'genius' that you will happily go beyond the contract-specified Sect IX variables, only "Please sign this Additional Work & Cost form"

 

[gr2vessels]

Good work Duwe6.
Cheers,
gr2vessels

 

[261073eam]

Your explanation have been extremely honest.

Copy, Paste and send to my collegue....answer: Everyone agre with you but said to fu*** inspector on behalf of client.

 

[Kiwi2671]

Duwe6,
Sorry to disagree but the ASME IX committee have created the confusion themselves.

QW 451.1 in the 2001 Edition shows
1/16" = 1.6 mm
3/16" = 4.8 mm
8" = 203 mm

QW 451.1 in the 2004 Edition
1/16" = 1.5 mm
3/16" = 5 mm
8" = 200 mm

If I remember correctly earlier editions (pre 2001) had 3/8" listed as 9.6 mm - now it is shown as 10 mm.

If they have rounded off 1.6 to 1.5 and 4.8 to 5 (nearest .5 mm)why has 9.6 been rounded off to 10 mm and not 9.5 mm ?
Regards,
Kiwi