Pressure relief valves are described herein. An example pressure relief valve includes a body having external threads to threadably engage another body having a pressurized chamber. Additionally, the pressure relief valve includes a relief valve orifice that is threadably engaged with the body via internal threads of the body. The relief valve orifice includes a seating surface. Further, the pressure relief valve includes a pressure-balanced piston assembly that is slidably movable within the body relative to the relief valve orifice and the seating surface to control the flow of fluid between the pressurized chamber and the relief valve orifice.