| 摘要 |
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. |
