Compact device for metering gas at variable pressure

A compact variable-pressure gas metering device for metering a volume of gas flowing a long a pipe, downstream from an expander-regulator, and comprising in succession;

• a flow straightener, a velocity-measuring flowmeter, an extender with a temperature takeoff and a silent flowrate limiter;
• wherein the extender is provided with an upstream flange and with a downstream flange, wherein the straightener is disposed between a flange of an upstream pipe for coupling to the expander-regulator, and an upstream flange of the flowmeter, wherein the limiter comprises an upstream web and a downstream web, wherein the extender is interposed between a downstream flange of the flowmeter and the upstream web of the limiter, wherein the limiter is disposed between the downstream flange of the extender associated with the flowmeter, and a flange of a downstream pipe, wherein the straightener comprises a support ring in which there are mounted in order, from upstream to downstream, a spacer in the form of an annulus, a first porous plate and a first perforated plate perforated by holes co-operating with the first porous plate, and wherein the limiter comprises said upstream web defining a second perforated plate perforated by a defined number n of calibrated holes of total flow section that is much less than the flow section of the first perforated plate, a second porous plate, and said downstream web defining a third perforated plate perforated by holes of section that is greater than the section of the calibrated holes of the second perforated plate of the upstream web and of total flow section that is much greater than the total flow section of the second perforated plate of the upstream web.