Started his career at the Dutch Weights and Measures (NMi) were he was involved in National Approvals of flow meters used for Liquid Custody Transfer applications. Joined the largest independent inspection company involved in training, auditing, inspecting and calibrating onsite proving facilities, most of them based on ball provers. HERMAN HOFSTEDE Sales Director, KROHNE Oil & Gas Joined KROHNE as a Product Manager for Custody Transfer Ultrasonic flow meters and represented KROHNE in several API committees. Presently responsible for global international sales for KROHNE Oil & Gas. Experience of 35 years in Custody transfer measurement
On Site & in Situ Proving of Liquid Ultrasonic Flow Meters using Master Meter technology
Different calibration concepts Prover tanks Bi-directional ball provers Uni-directional ball provers Compact provers Master meters
What do you want to achieve Less Maintenance Proof performance compliance Increase efficiency Longer working life Reduce calibration frequency Use On-board diagnostics
What is affecting Flow Meter performance flow disturbances, changes in flow profile within the pipeline Who is measuring the product Problems affecting metering Changes in product properties such as density, composition, viscosity Specifically related to Mechanical type of flow meters Quantities being measured, the range of flows Mechanical wear and tear
Considerations for the Master Meter calibration concept based on ultrasonic flowmeters No internal moving parts No wear or tear Stable geometric construction Fully welded all stainless steel construction Integrated diagnostics
Using a ball prover for calibrating ultrasonic flow meters Table deleted in API CH 5.8 2 nd edition Table included in API CH 5.8 1 nd edition
API MPMS Ch. 5.8 2 nd edition, Annex B Runs Repeatability Band % (R) Uncert. % 3 0,02 0,027 4 0,03 0,027 5 0,05 0,027 6 0,06 0,027 7 0,08 0,027 8 0,09 0,027 Repeatability versus uncertainty 9 0,10 0,027 10 0,12 0,027 11 0,13 0,027 12 0,14 0,027 20 0,22 0,027
Using Ultrasonic Master Meters Leading API Standards: API MPMS Ch. 4.5 Master Meter Provers 3 th edition 2010 included Ultrasonic and Coriolis Master Meters API MPMS Ch. 4.8 Operation of Proving Systems 2 nd edition 2013 included formula for calculating recalibration frequency API MPMS Ch. 5.8 Measurement of liquids by Ultrasonic Flow meters 2 nd edition 2011 removed recommended ball prover base volumes
API MPMS Ch. 4.8 paragraph 10.2 Master Meter Provers (reasons which have serious impact on re calibration frequency) All related to mechanical flow meters NOT for ultrasonic flow meters Worn or faulty parts no moving parts Damaged meter parts no moving parts Changes in fluid characteristics Reynolds flow meter not a volume meter Loss of internal material, abrasion material is high quality steel SS 316 Accumulation of foreign material (such as wax) build-up in the meter Diagnostics Reprogramming of electronic based maters Check sums Seasonal temperature changes in build temperature sensor
API MPMS Ch. 4.8 Annex B Method for determining the Frequency of Calibrating Provers Calculation based on following variables: Percent change in meter performance between two calibrations (Pf) Number of months (Mn) between calibrations Benchmark (0.06 % or less) Using following formula for calculating the Months to Next Calibration (MNC): MNC = [(Mn) x 0.06) / (Pf)]
Practical recalibration results of a 10 ultrasonic flow meter date of calibration Q 15-9-2005 13-8-2007 17-8-2010 31-7-2014 m3/hr Accuracy (%) 198-0,05-0,04 224-0,06 257-0,04-0,06-0,06 380-0,01-0,04-0,05-0,05 545 0,03 0,00-0,02 0,01 780 0,02 0,02 870 0,02 0,02 0,01 0,03 1045 0,01 0,04 0,01 0,04 1165 0,02 0,02 0,00 avg accuracy 0,01 0,00-0,03-0,01
Master/Duty configuration 2 x 100 % of Q max 3 x 50 % of Q max
Conclusions Ultrasonic flowmeters are adopted by International and National Oil Companies Diagnostic capabilities are acknowledged as one the major features of ultrasonic flow meters Ultrasonic flowmeters are in full compliance with National and International Standards Ultrasonic flowmeters can be calibrated with uni- or bi- directional displacement provers inline with API recommendations Master Meter calibration concept is in compliance with API standards Re-calibration frequency for ultrasonic Master Meters can be significantly reduced compared to mechanical type of Master Meters
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