First, I increased the image size of the original tweet by 400%, then manually traced a new (red) line over the existing one for better clarity.
The plot was then digitised using WebPlotDigitizer
After cleaning up the data a bit (removed a few bad points), I imported it into plotly to graph it out
NOTE: This is best guess without the original data but I'm pretty confident because of the final pressure reading (329.35 bar)