Fuel Pressure Gauge, 50PSI, R88-I-1872, Bureau of Aeronautics US Navy P-3 Orion although they typically attempted to

although they typically attempted to dive as steep as 90deg

and US Navy's PBY5A Catalina and PB4Y Privateer

ask questions

is a pressure gauge which accepts oxygen in liquid form at the inlet and oxygen in gas form exits at the outlet

See photo of the location of the instrument on the Flight Engineers upper instrument panel from the C-121 flight manual dated 1958

Fuel Pressure Gauge, 50PSI, R88-I-1872, Bureau of Aeronautics US Navy P-3 Orion although they typically attempted toHere is an aircraft Fuel Pressure Gauge, 0 50PSI, made by Bendix, with BU AERO US NAVY on its data label. Measures 2. 25in diameter and ~3in deep. Appears to be New Old Stock.