The gas discharging system is a device that releases gas for a short period of time through a release valve when the gas production equipment ignites and subsequent gas equipment malfunctions. The conventional venting device is set as a bell jar valve. Due to the low frequency of use of the venting system, as the contact time between the gas and the bell jar valve increases, tar and dust in the gas will continue to adhere to the bell jar valve, causing the bell jar valve to fail to release at the set pressure and even unable to move, posing a safety hazard to the system. Our self-cleaning bell jar valve can regularly clean away tar and dust adhering to the valve, keeping the bell jar valve clean at all times and ensuring set pressure release and operation when needed, ensuring system safety.