A depressurization system for an electrical transformer includes a pressure release assembly configured to be in fluid communication with a chamber of the electrical transformer. The pressure release assembly includes a rupture pin valve. The system may include an evacuation assembly having a blast chamber. The rupture pin valve includes a pin configured to buckle in response to a predetermined pressure applied to a surface of the rupture pin valve.

An on/off valve controls circulation of mediums in an upstream pipeline and a downstream pipeline of the on/off valve; a valve stem of the on/off valve is connected with an on/off actuating mechanism; the upstream pipeline of the on/off valve is connected with a pilot trigger mechanism through a communicating pipe, the pilot trigger mechanism is connected with the on/off actuating mechanism, and the pilot trigger mechanism triggers the on/off actuating mechanism. An isolation device is arranged on the communicating pipe and isolates the communicating pipe into an upstream portion and a downstream portion through a pressure sensing component. The pressure sensing component senses a medium pressure from the upstream pipeline and feed back the pressure to the pilot trigger mechanism, thereby causing an action of the pilot trigger mechanism. A non-viscous and incompressible fluid is filled between the downstream of the communicating pipe and the pilot trigger mechanism.

An on/off valve controls circulation of mediums in an upstream pipeline and a downstream pipeline of the on/off valve; a valve stem of the on/off valve is connected with an on/off actuating mechanism; the upstream pipeline of the on/off valve is connected with a pilot trigger mechanism through a communicating pipe, the pilot trigger mechanism is connected with the on/off actuating mechanism, and the pilot trigger mechanism triggers the on/off actuating mechanism. An isolation device is arranged on the communicating pipe and isolates the communicating pipe into an upstream portion and a downstream portion through a pressure sensing component. The pressure sensing component senses a medium pressure from the upstream pipeline and feed back the pressure to the pilot trigger mechanism, thereby causing an action of the pilot trigger mechanism. A non-viscous and incompressible fluid is filled between the downstream of the communicating pipe and the pilot trigger mechanism.