table UW-12

[wailunwu]

Hi
Can someone give me an example or a situation that demonstrates the use of joint efficiency E=0.85 (spot) for type 1 category D joint (e.g. nozzle neck to shell corner joint) per table UW-12 ? In what situation would this be critical in design? Many cases, I only see nozzle neck thickness calc with E=1. When do we ever need to look at or use the joint efficiency of nozzle neck to shell corner joint?

 

[david339933]

There is no E for nozzle neck to shell corner joint welds. Look at Table UW-12....corner joints. Notice Note 5 is written below "C and D" under Joint Category. Note 5 tells you "There is no joint efficiency E in the design equations of this Division for Category C and D corner joints. When needed a value of E not greater than 1.00 may be used."

If you were butt welding the nozzle to the shell, as in Fig. UW-16(f-1),(f-2),(f-3),(f-4). Then you could have E=0.85....assuming a Type I joint.