Weld Joint Efficiency Factor

[LTG BS]

Hello

I have a question regarding Weld Joint Efficiency Factors (E).

I am working in B31.1 and am looking to spec out a new 28"x.75" Thk. SA387 GR22 rolled, full penetration welded, x-ray, PWHT to be installed in an existing system. I am getting some plate rolled and welded to use.

I am using Eq.9 under 104.1.2 to determine the max pressure that this material can handle based on the existing design temperature of the system.

When I look under Appendix A I find a "E" value of 1.00 for A387 GR22 (Plate). But when I look under Table 102.4.3 Longitudinal Weld Joint the "E" value can change depending on how the plate is joined/welded.

Why does Appendix A give a value for S387 plate if they don't know how the plate is welded together? Shouldn't Table 102.4.3 always be used when using rolled plate?

 

[mk3223]

When I look under Appendix A I find a "E" value of 1.00 for A387 GR22 (Plate).

The selected joint efficiency factor of "E" is according to the pipe fabrication with the examinations as required for weld joints based on the Piping Code, i.e. Section 102.4.3.