the allowable loads on tank nozzles

hi

momentarily, I am working on a 24in line connecting to a huge Tank, I am trying to check the loads of the nozzle of the tank using API650 appendix P nomograms. I have got my axial force + longitudinal moment within the boundaries but checking the Fr+Mc, I am not quiet sure what the bottom boundary is. is it the x axis? or any minus value still within the tilted lines is also acceptable?

regards

The boundary is not the "x axis", but the figure itself (the tilted lines).

So it means that any minus(-) value of Mc is not acceptable per API 650 App P?

Please let us know?

I see your point, that doesn't make sense. I can see where plus and minus on the longitudinal moment would make a difference, but not with the circumferential moment.

I'll have to do some research on this issue.