| 摘要 |
The function of the cut-off device (3) is to halt the distribution of natural gas, at a constant flow rate, regardless of the pressure of the gas, in underground gas mains supplying homes (inhabited dwellings), in the event of the throughput exceeding the normal usage. It is characterised in that it comprises a device incorporated into a short length of pipe joining the main pipe (1) to the gas supply pipe (2) connecting the user apparatus of the user (4). In this device, an ogive (12) slides under the effect of the gas pressure (Pe) on a shutter (13) including sealing points (11) and defining a passage cross-section between the ogive (12) and the tapered housing of angle alpha . This assembly, subjected to a constant pressure difference predetermined by the spring (15), will move in order to bear against the seat (17) and halt the distribution of gas. This device makes it possible, regardless of the gas pressure (Pe) to cut off the gas at a constant flow rate. <IMAGE>
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