Measurements of Coefficients of Discharge for Concentric Flange-Tapped Square-Edged Orifice Meters in Natural Gas Over the Reynolds Number Range 25,000 to 16,000,000

摘要

The report describes the data acquisition systems and procedures used in the American Petroleum Institute (API)-sponsored orifice discharge coefficient project performed in natural gas flows and conducted at the test loop of the Natural Gas Pipeline Company of America (NGPL) in Joliet, Illinois. Measurements of orifice discharge coefficients for 6- and 10-inch diameter orifice meter runs were made using critical venturis for mass flowrate measurement with associated measurement of pressures and temperatures. Eleven venturis were calibrated at the Colorado Engineering Experiment Station, Inc. (CEESI). Measurements of absolute and differential pressure and temperature for venturi and orifice meter conditions were made using an automated data acquisition system. Temperature and pressure measurements were directly related to U.S. national measurement standards. Daily calibration of absolute and differential pressure transducers using pressure working standards was designed into the measurement procedures. Collected over a 2-year period, the database contains tests on 44 orifice plates in 8 beta ratios for two meter sizes (6- and 10-inches). The database contains 1,345 valid test points.