I was the only mechanical engineer in a startup biotech/biopharma company. The company had developed a high-pressure fluid technology that worked on a manual small-scale in the lab. It wanted to use it to manufacture pharmaceuticals at production scale. My job was to scale up vessel volume and automate the process for use in making human pharmaceuticals.
These systems had a common operating method that required pressurizing a pressure vessel to ultra-high pressure, up to 60,000 psi, with water. When I started, the company had small manually-operated vessels for laboratory work. The pressure was generated by a hand-turned screw. They later used a motor-and-chain driven screw that advanced a syringe designed to generate 60,000 psi without leaking.
I then designed and had built systems with vessels that had three times the lab-size internal volume and automated the operation with a PLC, an air-driven liquid pump, and a pressure transducer. These systems were used for low-volume verification runs in anticipation of clinical trials in humans. The results were positive. So now the company needed systems with vessels that were about 65 times the volume of the original lab size in order to manufacture the pharmaceutical product for human clinical trials. I designed them and had them built.
With the guidance of our contract manufacturer, we gained FDA cGMP approval to use this machine to manufacture pharmaceutical product intended for human use. One key engineering design requirement was that the desired time rate of pressure growth for the process had to be the same regardless of vessel size. In order for that relationship to be maintained, the required flow rate of water being pumped into the vessel was roughly proportional to the internal volume of the vessel.
When we operated the initial manual lab system and the 3X larger lab verification version, head loss was never an issue. Common knowledge was that head loss would never be an issue with this technology, that the flow was just too slow. The first time my great-technician-ever (GTE) team member and I filled the 65X volume vessel -- requiring 65X the flow rate of the smallest vessels -- we found the water increased in temperature by about 60⁰ C. Yikes!