API TR 13M-5-2018 pdf free download
API TR 13M-5-2018 pdf free download.Procedure for Testing and Evaluating the Performance of Friction (Drag) Reducers in Aqueous-based Fluid Flowing in Straight, Smooth Circular Conduits.
3 Measurement and Precision Pressure shall be measured to a relative accuracy of 0.5 % of the full-scale reading of the device. Flow rate shall be measured by a device having a relative accuracy of 0.5 % of the full-scale reading. Temperature shall be measured to a precision of ± 1 °C ( ± 2 °F). All other quantitative measurements shall be made to a precision of 2 %, unless specified otherwise. 4 Instrument Calibration The instruments associated with these procedures shall be calibrated according to each manufacturer’s recommended method and frequency. 5 Friction Loop Calibration 5.1 Introduction Fresh water is pumped through the flow conduit at various flow rates in turbulent flow regime in order to gather pressure drop data. These data will be analyzed to determine the internal diameter (ID) of the flow conduit (pipe). 5.2 Flow Loop Schematic Figure 1 represents components of a typical flow loop system.
5.3 Calibration Procedure The purpose of this section is to accurately determine the ID of the tubing. This calibration is performed by comparing the experimental data with theoretical values, using a Fanning friction factor logarithmic plot vs solvent Reynolds number for fresh water. The theoretical values will be calculated using the Drew correlation [1] . Fresh water is pumped at various flow rates in turbulent flow regime. Turbulent flow regime for this document indicates a solvent Reynolds number greater than 4000. The calculation for solvent Reynolds number is indicated in the Data Analysis section. A minimum of four flow rates in turbulent flow regime shall be measured. A recommended range of flow rate is such that the solvent Reynolds number spans a minimum of two logarithmic cycles or orders of magnitude. The flow rate is set at a desired value, and the steady-state pressure drop data across straight tubing length is recorded. Then, the flow rate is increased to the next desired value, and the corresponding pressure drop is recorded. Between tests, and prior to introducing a new test fluid, the system calibration should be verified by pumping fresh water at two different flow rates within the flow rate range used: one at a low rate and the other at a high rate. The differential pressures at those rates should be compared with previously gathered data. If the data do not match, the pipe test section is not properly cleaned and should be flushed/cleaned further.
A new internal pipe diameter is then selected and the trial-and-error procedure is repeated until the average percent deviation is less than or equal to 3 %. NOTE If deviation of 3 % is not achieved after the trial-and-error procedure is followed, then the pipe may have an internal roughness and cannot be considered as a smooth pipe. 5.6 Calibration Example—Determination of Internal Pipe Diameter The example presented here is to illustrate the analysis procedure of the flow data gathered in smooth circular pipe and to prepare plots of wall shear stress vs wall shear rate and Fanning friction factor vs solvent Reynolds number. The data are gathered by pumping water through a 0.5 in. Schedule 40 pipe [theoretical ID 0.0158 m (0.622 in.)] and monitoring differential pressure across 3.05 m (10 ft). The experimental data are listed in Table 1, and calculated results are shown in Table 2.
A logarithmic plot of wall shear stress vs wall shear rate is prepared and shown in Figure 2. The data is fitted using the regression analysis, and the slope of the line is calculated. An approximate value of the slope is 1.8 (the exponent in the displayed fitted equation shown as 1.776) would indicate turbulent flow of a Newtonian fluid such as fresh water. If the slope value is within 1.75 to 1.85, it is acceptable. The flow rate and pressure drop data is converted to Reynolds number and Fanning friction factor, respectively, using the manufacturer-supplied pipe ID as a start. The internal pipe diameter is then varied to obtain the best match of the experimental data with the Drew correlation. Figure 3 depicts this data on a logarithmic plot. The Drew correlation for smooth pipe is also plotted on this graph. It was found that the internal pipe diameter of 0.011 m provided the best match, with an absolute average deviation of 0.89 %. This internal pipe diameter obtained from this baseline exercise is then used as the pipe ID in the analysis of friction reducer data later on.