API 570 T-MIN and MAWP with no pipe information
API 570 T-MIN and MAWP with no pipe information
(OP)
I am currently working as an API pipe inspector on a loading dock. A majority of the piping is overwater. That being said besides the design pressure and operating temperature, the customer has absolutely no previous history on the piping. Therefore, I will calculate the MAWP and T-Min per API 570 and 574 in order to provide recommendations.
However I am not sure what the Stress value or Y coefficient should be since there is no information on the pipes, by the way all piping is carbon steel.





RE: API 570 T-MIN and MAWP with no pipe information
RE: API 570 T-MIN and MAWP with no pipe information
RE: API 570 T-MIN and MAWP with no pipe information
Select the lowest allowable stress from all carbon steel grades tabulated within the original design code;
Assume minimum NDT and select the appropriate weld quality/strength reduction factors;
Select a Y value consistent with carbon steel and the design temperature.
A first pass could be done on circumferential stress alone but there's also longitudinal stress that may be more onerous for MAWP and tmin - if you don't know what the piping loads are there is a routine in API 579 that you could follow, see the section on Supplemental Loads in Annex 2C.
RE: API 570 T-MIN and MAWP with no pipe information