Performance Evaluation of 200 and 400 mm PARTI MAG II, Bailey Fischer & Porter Electromagnetic Flowmeters, Installed in Partially Filled Pipes

Transcription

1 Performance Evaluation of 200 and 400 mm PARTI MAG II, Bailey Fischer & Porter Electromagnetic Flowmeters, Installed in Partially Filled Pipes A Report for NMSPU Department of Trade and Industry 151 Buckingham Palace Road London, SW1W 9SS Project No: WSDC54 Report No: 195/99 Date: 13 April 1999

2 Flow Centre National Engineering Laboratory East Kilbride, Glasgow, G75 0QU Tel: Fax: Performance Evaluation of 200 and 400 mm, PARTI MAG II, Bailey Fischer & Porter Electromagnetic Flowmeters, Installed in Partially Filled Pipes A Report for NSMPU Department of Trade and Industry 151 Buckingham Palace Road London, SW1W 9SS Prepared by: Mr W C Brunton... Approved by: Mr J Williamson... Date: 13 April 1999 for Dr F C Kinghorn General Manager Report No: 195/99 Page 1 of?

3 C O N T E N T S Page EXECUTIVE SUMMARY INTRODUCTION DETAILS OF THE ELECTROMAGNETIC FLOWMETERS mm NB Flowmeter mm NB Flowmeter METHOD OF TEST mm NB Flowmeter mm NB Flowmeter UNCERTAINTY RESULTS mm NB Flowmeter mm NB Flowmeter... 5 APPENDIX: MANUFACTURER S SPECIFICATION FOR BAILEY FISCHER & PORTER, PART MAG II, ELECTROMAGNETIC FLOWMETERS FOR PART FILLED AND FULLY CHARGED PIPE FLOWS... Report No: 195/99 Page 2 of?

4 EXECUTIVE SUMMARY One 200 and one 400 mm nominal bore PARTI MAG II, electromagnetic flowmeter, designed for measuring flowrates in partially filled pipes and manufactured by Bailey Fischer & Porter were calibrated in the large water flow facility at NEL. The 200 mm flowmeter was first installed for calibration in the NEL facility in December 1997 and following that a series of investigations were carried with the Manufacturer to resolve problems with the meter. However, although the meter was calibrated successfully at the Manufacturers premises, these results could no be replicated at NEL. The 400 mm flowmeter was calibrated in May 1998 at various flowrates and hence various fill heights, including full pipe conditions. The flowmeter was then calibrated at three fill heights chosen approximately in the lower half, at the middle, and in the upper half of the pipe line and the flowrates varied with the fill heights held nominally constant. 1 INTRODUCTION This is one of a series of evaluations carried out under DTI Flow Programme Project Reference WSDC54, on 200 mm and 400 mm nominal bore (NB) electromagnetic flowmeters designed for use in part filled and fully filled pipe flows. The calibrations were carried out in the large water flow facility at NEL. The facility is normally used for fully filled pipe flows, but a modified method of use allowed the water level in the test lines to be held steady at the selected value, whilst the flowrate was measured using the primary gravimetric system. This report gives the results of the flowmeter calibrations. A comprehensive report describing the flow measurement facility, test method and operational findings of the flowmeter is in preparation. 2 DETAILS OF THE ELECTROMAGNETIC FLOWMETERS mm NB Flowmeter Meter type: Manufacturer: Primary: Converter: PARTI MAG II range Bailey Fischer & Porter Model No ODP4111A Order No 9704L1080/A1 Model No 50XPZ101A Order No 9704L1080/B mm NB Flowmeter Meter type: Manufacturer: Primary: Converter: PARTI MAG II range Bailey Fischer & Porter Model No ODP4111A Order No 9703L0007/A1 Model No 50XP2101A Order No 9703L0007/B1 Report No: 195/99 Page 3 of?

5 Note: Both flowmeter were calibrated in water with the electrical conductivity varying between µs/cm. 3 METHOD OF TEST mm NB Flowmeter The 200 mm NB flowmeter was installed in the 200 mm NB test line with approximately 30D upstream and 14D downstream of similar diameter pipework. Care was taken to ensure that the flowmeter was mounted with the axis of the upper electrode pair horizontal using the spirit level installed in the primary junction box for this purpose. The flowmeter and the adjacent pipework along with the upstream pipework were level, and while the rest of the downstream pipework was running at a slight decline, the bubble in a spirit level used for checking this was either within or just over the appropriate line marking on the spirit level. Figure 1 shows the internal diameters of the pipework adjacent to the flowmeter. The fill heights were measured at the two perspex spool sections using a vernier height gauge and the mean value corrected to give the fill heights relative to the flowmeter mm NB Flowmeter The 400 mm NB flowmeter was installed in the NEL 457 mm NB pipe test line with approximately 20D upstream and 14.5D downstream of 400 mm NB pipework. The upstream pipework along with the flowmeter and its adjacent pipework were level while the rest of the downstream pipework was running at a slight decline. Figure 2 shows the internal diameters of the pipework adjacent to the flowmeter. The fill heights were measured at the perspex pipe section using the vernier height gauge and corrected to give the fill heights at the flowmeter. 4 UNCERTAINTY The large water test facility, used for the present calibrations, is NAMAS accredited with a best measurement capability uncertainty of 0.1 per cent of measured flow. The reported expanded uncertainty is based on a standard uncertainty multiplied by a coverage factor k=2, providing a level of confidence of approximately 95 per cent. The uncertainty evaluation has been carried out in accordance with UKAS requirements. 5 RESULTS mm NB Flowmeter In the initial test in December 1997, covering several flowrates up to approximately 20 l/s, the flowmeter gave erroneous results. A representative from the manufacturer checked the flowmeter and a printed circuit board in the converter was changed. However, the flowmeter still gave erroneous results and it was decided to return the flowmeter to the factory for further examination. After the manufacturer had checked the meter, a representative from NEL witnessed the flowmeter being calibrated at the factory and it gave deviations within its specified uncertainty, which for this flowmeter is within 5 per cent for flowrates up to 6 l/s and 3 per cent for higher flowrates. Report No: 195/99 Page 4 of?

6 The flowmeter was returned to NEL and re installed in the NEL facility in January Test points were taken at various flowrates (and hence various fill heights) including full pipe conditions up to a flowrate of approximately 22 l/s. This was achieved by adjusting a valve upstream of the test line keeping all other valves in the test line open and the water allowed to fall under gravity to the weighbridge. At flowrates of approximately 3 l/s the flowmeter gave deviations of approximately 29 per cent. At flowrates of approximately 6.5 l/s to 16 l/s the deviation varied from 3 per cent to 6 per cent and at 30 l/s, (full bore conditions), the deviation was approximately 8 per cent. On further discussion with representatives from the manufacturer, it was thought the high electrical conductivity values of the water at NEL was causing the problem with the flowmeter affecting the lower pair of electrodes, although the information for this flowmeter does not specify any upper limit for the conductivity. It was decided to postpone further testing with this flowmeter until the problem had been resolved mm NB Flowmeter The calibration results are given in Tables 1 and 2. In the first part of the test, test point Nos 1 4, 11 15, 17 18, and 25 27, (Test No 3188C), the flowmeter was calibrated at various flowrates and hence various fill heights, including full pipe conditions, up to a flowrate of approximately 122 l/s. This was achieved by adjusting a valve upstream of the test line and the water allowed to fall under gravity to the weighbridge. These results are shown in Figure 3. In the second part of the test, the rest of the test points including the test points in Test No 3188D, were taken at three fill heights chosen approximately in the lower half, at the middle, and upper half of the flowmeter diameter and the flowrates varied up to 163 l/s. These conditions were achieved by adjusting the same upstream valve along with an additional valve at the downstream end of the test line. These results are shown in Figure 4. Test point Nos 13 and 14 are excluded from the graphs as they gave large deviations. This may have been due to the fill heights being close to the lower pair of electrodes and the high value for the electrical conductivity having an effect at this level. The velocities given in Tables 1 and 2 are mean values derived from the wetted cross sectional areas of the flowmeter and the volumetric flowrate in the pipe. Report No: 195/99 Page 5 of?

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11 APPENDIX MANUFCTURER S SPECIFICTION FOR BAILEY FISCHER & PORTER, PARTI MAG II, ELECTROMAGNETIC FLOWMETERS FOR PART FILLED AND FULLY CHARGED PIPE FLOWS Report No: 195/99 Page 10 of?