Hi, everybody.

In pipeline road crossing calculation using API 1102, the allowable total effective stress is SMYS X Design Factor.

In B31.8, the combined stress for restrained pipe, the allowable is K X SMYS X T. where K should not exceed 0.9.

MY question is that can K (0.9) be use in place of the design factor in road crossing analysis, because the total effective stress is the combination of max. circumferential stress, max. longitudinal stress and max. radial stress.

My pipeline is class 3, i.e Design Factor is 0.5, but the pipe failed the road crossing analysis. i just want to know if i can use 0.9 for the analysis.

Thanks for ur help.

OML

No. You will need to use F=0.5. As stated in B31.8 section 841.145, design factor shall be as per table 841.114B.

Thanks for your help, I realy appreciate.

The problem I'm having now is that my boss does not want to accept the result because he has order for the pipe. Please what can i do?

Thanks.

Thanks for your help, I realy appreciate.

The problem I'm having now is that my boss does not want to accept the result because he has order for the pipe. Please what can i do?

Thanks.

Thanks for your help, I realy appreciate.

The problem I'm having now is that my boss does not want to accept the result because he has order for the pipe. Please what can i do?

Thanks.

You could consider increasing burial depth if it will help reduce the impact factor enough. Otherwise you could consider using a barrier or casing for the pipe.

thanks i really appreciate

Hi,

Please, I do have a rest support directly under ESDV valve, i will like to know how to model this and what effect does it have on the valve.

thanks