Description
Differential pressure flow measurement devices rely upon correct installation to achieve the accuracies for which they are known. Common problems affecting accuracy are insufficient straight pipe, inferior quality welds, pipe circularity, pipe tolerances and misalignment amongst others. AVCO fabricates complete meter runs per AGA 3, ASME MFC-3M or ISO 5167 standards as a total solution to your flow measurement needs and they are supplied fully assembled, tested and calibrated (if required). The upstream and downstream pipe lengths are sized to suit the application, including flow straighteners (if necessary) and we only select the best quality pipe for roundness and straightness. For relatively small-bore meter runs up to 2” in size, accuracy is affected quite dramatically by imperfections in standard pipe bores due to irregularities in surface finish, roughness, straightness and roundness. To overcome these problems, AVCO supplies honed flow tubes per ASME MFC-14M with a surface finish of 5 to 10 RMS and a tolerance of ±0.001”. This gives accuracies of ±0.75% or even ±0.25% with flow calibration. All other elements are similar to a standard meter run. Because AVCO believes in flexibility, we can supply the meter runs with or without the manifold, dP transmitter, temperature transmitter or flow computer. If the end user has preferred brands, we can supply and install those as required.
