dP Flow Measurement on Elbow in pipeline
dP Flow Measurement on Elbow in pipeline
(OP)
I would like to measure flow by means of the dP over an Elbow. The 36" steel pipeline is used for cooling water. Temperature is around 30 deg c . I would like to have a formula which gives the dP as function of the flow. The max flow speed is approx 2 m/s
Thanks.
note it is a long radius elbow
Thanks.
note it is a long radius elbow





RE: dP Flow Measurement on Elbow in pipeline
RE: dP Flow Measurement on Elbow in pipeline
Maybe you could characterize the DP range with a rented clamp-on flow meter upstream?
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Elbow Meters
As fluid flows around an elbow, centrifugal force makes pressure on the outside wall higher than pressure on the inside wall. This pressure difference is proportional to flow, and its coefficient can be estimated from knowledge of elbow dimensions. For more accurate measurement, an elbow (with at least 10 diameters of straight pipe upstream - straightening vanes are recommended to stabilize swirling flow - and 5 diameters downstream) should be flow calibrated. If welds on an inlet elbow and pressure taps are carefully made, elbows will calibrate with a very stable calibration curve.
These units, however, are more often used for flow control (high repeatability) rather than for accurate flow measurement. Piping systems already have elbows present, and their use as a meter adds no pressure loss not already present. But normal pipeline velocities do not generate differentials (normal maximum about 9 inches), and this limits accuracy and severely limits rangeability.
RE: dP Flow Measurement on Elbow in pipeline
RE: dP Flow Measurement on Elbow in pipeline