Conceptual design for a theoretical hydraulic circuit pressure relief or pressure control valve which requires little effort or force to open, even when containing or controlling very high pressures.
The innovative aspect of this valve is that it should require very little force to open as the plug (the yellow piece in the renders) doesn't need to open against a pressure gradient and doesn't need to reduce (even by a minute amount) the internal volume of the valve's main chamber or the hydraulic or high pressure fluid circuit the valve is connected to, in order to open.
At the same time, the valve can also not be opened by the pressure in the circuit it's connected to. This is because its obstructing element, in addition to not having to open against a pressure gradient, also doesn't need to resist a pressure gradient to stay closed either.
The valve opens by retracting the plugging element (the yellow component in the renders) from the outlet duct in the valve's body, which it inserts into from the valve's main chamber. This allows fluid from the valve's main chamber (and whichever hydraulic or high pressure circuit it is connected to) to escape through the outlet channel.
The plugging pin is advanced forward and kept in position by way of actuation by a solenoid (depicted in brown in the renders), which is situated in a different chamber of the valve, on the opposite side of the valve body (pictured in blue in the renders) from the outlet duct and isolated from its main chamber by a wall with a hole in it for the pin to pass into the main chamber through and continue on into the outlet channel.
The valve's solenoid compartment itself has an inlet port on the side and an outlet port on its end (on the tip of the green end cap in the renders).
The inlet port is to allow low pressure fluid from the valve's outlet channel (on the opposite side of the valve's body, routed from there through a hose or tubing not shown in the renders) in to the solenoid compartment and the outlet is to allow return of low pressure fluid from the valve's solenoid chamber (which would otherwise accumulate there and possibly start increasing in the solenoid compartment) back to the main low pressure section (such as the tank or reservoir) of the hydraulic or high pressure circuit the valve is connected to.
The outlet port also fulfils the function of drainage of fluid leaked into the valve's solenoid chamber from its main chamber, between the obstructing pin and the valve body, through the hole in the wall separating the solenoid chamber from the valve's main chamber. Fluid flowing past the solenoid cools it. The solenoid needs to stay activated for as long as the valve needs to stay closed.
As the valve defaults to its open state when not powered on, it can be considered to be fail-safe as well.