Yes, the joint efficiency and extent of X-ray "RT" is listed on the U-1 Vessel Data Sheet. The quantity of RT, and thus the joint efficiency, and thus the effective thickness of the heads & shell have to be defined by the Engineer of Record.
No RT = 70% Efficiency = 0.5" material calculates at 0.35"
Spot RT = 85% Efficiency = 0.5" material calc's at 0.425"
Full RT* = 100% Efficiency = 0.5" calc's at 0.5"
Spot RT is usually 1 single shot and 1 piece of film. Highly recommended to take your [theoretical] 0.5" vessel from 0.35" useable material up to 0.425" This is a 27.5% increase in usable thickness for the price of a single RT.
Full RT is not 100% RT. Full entails 100% of long seams, Spot Shots on the circumferential welds, including heads, and no RT on the nozzles. Usually only cost-effective on stainless steels and more expensive alloys.
