Purchased Welded Tubing Joint Efficiency Factor

[rjw57]

As per subject, I am using welded tubing purchased from a tubing supplier per A249, A269 or A778. What should I be using as a longitudinal joint efficiency factor and how do I figure this out in the future?

Thanks

 

[TomBarsh]

Assuming that you are referring to ASME Boiler and Pressure Vessel Code Section VIII Div 1:

Refer to paragraph UW-12(e). Welded pipe and tubing is to be treated in the same manner as seamless material except that the allowable tensile stress taken from the line entry in Section II Part D for the welded material.

Be aware of Note G24 to Section II Part D Table 1A. This note permits the allowable longitudinal tensile stress to be divided by the 0.85 joint efficiency factor already incorporated into the published allowable tensile stress. The published stress for such material forms is assumed to be for circumferential stress.

Tom