Pyrotechnic pressure generator

A method of actuating an operational device that is associated with a well system and/or that is located subsea, the method comprising:

• activating a propellant in a pyrotechnic pressure generator, the pyrotechnic pressure generator comprising an elongated body having a first end, a second end, and a bore extending axially from a barrier to the second end, a piston slidably disposed in the bore, the propellant located in a chamber between the first end and the barrier, a gas outlet orifice through the barrier providing gas communication between the chamber and the bore, and a port at the second end in communication with the operational device;
• producing a gas in the chamber in response to activating the propellant, the gas escaping through the gas outlet orifice into the bore and the gas applying a force to the piston;
• moving the piston in a stroke from a position proximate to the barrier to a position proximate to the second end;
• communicating, in response to moving the piston, a pressure to the operational device that is equal to or greater than an operating pressure of the operational device;
• and
• actuating the operational device in response to communicating the pressure to the operational device.