D-Zero Signal Board Feed-Thru, Instrumentation and Hi-Voltage Boxes

The three boxes being reviewed all operate at a pressure of less than 15 psig. Since they are relieved at 13 psig, they fall outside the scopes of the ASME Pressure Vessel Code, Fermilab Engineering Standard SD-37B, and Chapter 5031 of the Fermilab Safety Manual, therefore a Pressure Vessel Engineering Note showing compliance with SD-37B is not required. In calculating the design stresses, only the largest of the three boxes, the signal board feed-thru box, was analyzed. This box had the largest spans and areas and would experience the largest pressure-related forces. The thinnest walls of each box were found to be in the top plates and they were also the side of the box which exposed the largest amount of area to internal pressure. The signal board feed-thru box top plate had at least twice the pressure area than either the instrumentation or hi-voltage boxes' top plates. This large disparity overshadows the slight difference in top plate thicknesses between the three boxes (0.56-inch vs. 0.25-inch and 0.3125-inch, respectively). Therefore, we felt the analysis of the larger signal board feedthru box would justify the design of the smaller instrumentation and hi-voltage boxes. Appended to the end of this engineering note are the weld procedure, assembly report and the pressure test procedure & results for the signal feed-thru box. Also, included as a reference is a list of the drawing numbers for the parts and assembly of the signal board feed-thru, instrumentation and hi-voltage boxes