Originally Posted by refugio
Are you implying that a smaller area somehow changes the pressure (expressed as force over area)?
And what makes you believe that pressure does not go to 1000 psi? That's the pressure specified by SeaStar for bleeding their system - it's not possible to commission a system that won't hold that pressure. Are you thinking that because most of the time the system isn't pressurized that somehow an average pressure becomes relevant?
Also, note that 1000psi is "minimum operating pressure" for Capilano/Teleflex/SeaStar hydraulic hose. The "burst pressure" is 5000psi.
Fittings typically don't have proportionally thinner wall as the diameter decreases. So as the mean diameter decreases, so does the hoop stress generated by internal pressure. You will often see small diameter fittings with a much higher rating than larger diameter fittings.
Yes you can generate high pressure by cranking the helm into the rudder stops, but normal operating pressure of the helm is a fraction of the tested pressure. Most systems have have reliefs at 900-1000 psi to prevent seal damage.
SAE 100R hose was the typical hose used before vendors came up with specialized hose.
I too like isolation valves, but they can be a curse, as they are often just another leak point later. I would want a cylinder bypass valve for bleeding, and emergency rudder control though.
I know nothing about starboard. Never used the stuff.