Layered Cylinders Section VIII Div. 1

[PVinspector]

Supposed I have two cylinders layered, with staggered seams, and each has a seam eff. of 0.70 (70%). How do you figure the combined or total efficiency of the cyliner? Is (1.0 + 0.7) / 2 =0.85 correct?

Or for 4 or 10 layers?

I know the Guidebook for Design my Farr & Jawad uses something like that, just wondering what else is out there.

 

[metengr]

PVinspector;
Go to ASME B&PV Code, Section VIII, Div 1 Part ULW, you can review design of welded joints (ULW-17).