An elbow flow meter measures the flow of fluid due to the change in pressure as it flows around a pipe elbow.
How it Works
When fluid flows around a pipe bend there is an increase in pressure with radius, i.e. the pressure at the outer wall of the bend is higher than that at the inner wall.
The pressures at the inside and outside of the bend can be measured via pressure tappings in the pipe and the flow rate of fluid determined using the difference between the two measured pressures.
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Well proven, simple, and robust metering principle
Low space requirements
No restriction to flow in the flare line
Not suited for low flow velocities as the differential pressure is too low
No design standards for elbow meters in gas service
Meter may need initial calibration against an ultrasonic meter
Higher uncertainty than ultrasonic meters. Some measurement uncertainty associated with prediction of flare gas density
Application of ASME design standard is limited to liquid (incompressible) line fluids
No case study available at this time.
Differential pressure meters work on the principle of calculating a flow rate based on the change in pressure between two measured points.