Abstract: The invention relates to a gas pressure safety device used in the natural gas distribution systems leading to homes or other customers. This safety device is connected to a gas venting device that allows excess gas to exit therefrom. The safety device is made up of a needle valve, a pressure sensing pilot and a spring-diaphragm actuator. The needle valve is used to restrict the rate of gas flow into the actuator to a rate less than that that can be vented by the pressure sensing pilot. When an excess pressure is generated in the distribution system, the pressure sensing pilot senses when to exhaust the excess gas through the actuator and out of the gas venting device to the atmosphere.

Abstract: The safety device of this invention is made up of a source pressure regulator, an inspirator and a pressure sensing pilot connected to a gas venting means. All of these components are in gas flow connection with each other. The pressure sensing pilot has a valve that will open upon overpressurization of the gas transport system containing these components. Upon this overpressurization the inspirator will cause a vacuum to be formed which will open or activate the gas venting means and permit the excess gas to be vented to the atmosphere.

Abstract: The gas distribution system has a main gas line in gas flow connection with several components including a gas pressure safety structure. A pressure regulator is located on a front or forward portion of the main gas line and reduces the gas pressure at a point in the main gas line subsequent to the pressure regulator. There is an auxiliary gas line that extends from a point on the main line before the gas pressure regulator to the gas pressure safety structure. The gas pressure safety structure has in gas flow connection a source pressure regulator, as inspirator and a pressure sensing pilot all in gas flow connection with a gas venting device. Upon overpressurization the pressure sensing pilot will be activated and the inspirator will cause a vacuum to be formed in its connection with the gas venting device. This vacuum will open the gas venting device to permit the excess gas to be vented to the atmosphere.