BTW in my past life, I was an engineering tech, in Aerospace, after I left the USAF, I did contract work on the hydraulic dry pump that ran the Nitrogen fuel tank replentishment pump on the C5 Galaxy, Air Force Transport Plane. I ran and tested hydraulics with heaters that would ramp the hydraulic oil up to 350 degrees F, at 5,000 PSI.
I can tell you how that squeeled like hell when warming it up, especially when we dropped the temp down to 50 below zero, so we could cycle temps up and down... to do performance checks..
The nitrogen fills the fuel tanks as an inert gas to replace oxygen in fuel tanks while the fuel is used up. This is so if there is enemy fire or an explosion the inert gas to help prevent fires.
Anyways, I am not a stranger to mechanics... while a kid I learned mechanics rebuilding everything on a car from the nuts and bolts up. But, since I became disabled, It's very hard to do the work.
Many years has passed too,,,,
