I need to release pressure of around 50psi, after 3-4 seconds of initiating, from a vessel using a mechanical switch. I had considered a pneumatic solenoid, but I want to forgo the inconvenience of charging the device with electricity in addition to the air, as well as save the space that would be needed for the bulky solenoid, circuitry, and battery.
I therefore need what would essentially be a "mechanical-fuse" that releases pressure after a delay when triggered. I considered a screw-type piston that gets forced along a track by the air in the vessel itself, which at a set psi could guarantee a specific time of release. I also need the system to be no longer than 5 inches along the axis of released pressure. Does a "screw-fuse" sound like a viable idea? Does anyone have any other sources for a mechanical fuse of this type, or an idea of their own?