GR 448 Cat II -45C vs. GR 448 Cat III -45C vs
GR 448 Cat II -45C vs. GR 448 Cat III -45C vs
(OP)
Hello,
A question about Cat II vs Cat III. I have been asked if Gr 448 Cat III pipe can be substituted for for GR 448 Cat II. (both to -45C)
What are the primary differences between the categories? Both are notch toughness tested, Cat II 0s 60% shear, Cat III has no shear testing.
I cant find anything else that lists the differences so any insights/links are appretiated.
Thanks
specs
A question about Cat II vs Cat III. I have been asked if Gr 448 Cat III pipe can be substituted for for GR 448 Cat II. (both to -45C)
What are the primary differences between the categories? Both are notch toughness tested, Cat II 0s 60% shear, Cat III has no shear testing.
I cant find anything else that lists the differences so any insights/links are appretiated.
Thanks
specs





RE: GR 448 Cat II -45C vs. GR 448 Cat III -45C vs
Unless you are in CO2 service, in which case you can never make the substitution; or unless your hoop stress exceeds the upper bound for Pipe Threshold Stress Value (PTSV) for the corresponding pipe size as tabulated in the right hand column in Table 5.3, in which case again the substitution is not permitted.
The intent of the Code is to limit the potential length of crack propagation to a few joints of pipe.
RE: GR 448 Cat II -45C vs. GR 448 Cat III -45C vs
Stupid iPad auto-correct.
RE: GR 448 Cat II -45C vs. GR 448 Cat III -45C vs
I will blame the stupid iPad for that one, too.
RE: GR 448 Cat II -45C vs. GR 448 Cat III -45C vs
Yes, the iPad continues to dominate, control and auto correct!!! If only it could decipher standards!!
thanks
specs :)
RE: GR 448 Cat II -45C vs. GR 448 Cat III -45C vs