Abstract: A method for releasing a fluid from a pressure vessel assembly, the method including the steps of providing: —a pressure vessel; a piezo electric device; and an electric field generator; arranging the piezo electric device in a sealed relationship with a part of the pressure vessel, thereby providing the pressure vessel assembly, providing a fluid contained within the pressure vessel assembly under pressure, and using the electric field generator to apply an electric field to the piezo electric device, such that the piezo electric device fails, thereby releasing the fluid from the pressure vessel assembly.

Abstract: A servovalve has a pilot stage having a piezoelectric element actuating a pilot stage spool valve, which pilot stage spool valve comprises an output control fluid line to a main stage.

Abstract: A firing mechanism (25) for activation of a pneumatic stored energy system having a motor (50) connected to a vessel (20) by a tether, the vessel (20) containing a pressurized fluid. Activation of the motor (50) causes the tether to wind, applying a linear force to an attachment region of the vessel, fracturing the vessel (20) to release the pressurized fluid thereby activating the pneumatic stored energy system.