The Dynomometer Card is covered on Guidebook 7 PRD 11. It shows
the Surface Card (top total load) and Pump Card (bottom fluid load).
Note the graph is Load (lb) versus Position (in).
Peak PRL & Min PRL are the highest and lowest point on the y-axis in inches, multiplied by the lbf/in conversion.
So if PPRL is about 4.4" and MPRL is 1" with a conversion of 5,000 lbf/in you've got about 22,000 lbf and 5,000 lbf for PPRL & MPRL.
Of concern is the max stress on the top rod of each section. So PPRL is important. For a quick reminder on axial stress, see GB 2 DRL 6; it's just tension / area.
So given a rod size of 86, you have 1" top rod diameter (see the rod name/size explanation on 7 PRD 10; a 86 rod = 1" dia top rod with an area of 3.1415(1)/4 = 0.785 in^2). So stress is about 22,000/0.785 = 28,000 lbf/in^2.
For the PPRL how did you get 4.4"? Looking at the dynamometer card provided, the peak PRL is 3.2"
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