2009-01-26 - ABB's new compact orifice flow meter – OriMaster – has been tested and its performance proven at the Advantica Flow Centre, near Durham in the UK.
OriMaster comprises an orifice plate (designed to ISO 5167), impulse piping, manifold and DP transmitter – all fabricated and assembled to form a one-piece, pressure-tested flow meter.
During its development, four OriMaster meters were calibrated using natural gas to verify their flow measurement accuracy:
2 off 2” meters (Beta values of 0.4 and 0.65)
2 off 6” meters (Beta values of 0.4 and 0.65)
The test rig was pressurized up to 50 bar g and the natural gas flow rate reached a maximum Reynolds number of 1.15E07 (equivalent to just under 55,000 kg/hr). A minimum of five readings at each of six flow rates were taken, from both the OriMaster under test and the Advantica master meters, allowing the accuracy of flow measurement to be calculated at each point. The flow centre’s turbine meters were used as the reference and analysis of the natural gas was taken every four minutes to ensure that the composition of the gas coming from the gas grid was consistent during the test period.
The results of the testing reinforced ABB's opinion that accurate positioning of orifice meters centrally between flanges is essential. Three of the units were centralized using ABB's centralisation device and one was centralized only "by eye". The latter process proved unreliable as the results were noticeably worse – by approx 0.5 to 0.75% - than the other three meters. Indeed the accuracy fell outside the OriMaster specification. All units installed using the device were fully within the requirements.
This confirmed that correct centralization was vital for good measurement accuracy and justified ABB's decision to supply a centralizing device with every OriMaster. This tool gives ABB's customers the ability to guarantee correct centralization and hence gain access to the best flow meter performance.
It was the combination of Advantica's capabilities and their independence that led to ABB selecting them to perform these tests. Advantica is an independent, global engineering consultancy, service and solution provider, supporting clients in the gas, oil, water and electric industries.
The Flow Centre - formerly under British Gas - specializes in the calibration of high pressure, high flow gas meters, using natural gas taken from (and returned to) the UK National Gas Transmission System . This UKAS approved site has the capability to test meters ranging from 1” to 30” at pressures of 38 – 55 bar at flow rates up to 19000m3/hr.
“OriMaster's test results confirm that it is truly a Master in the compact flow meter class and confirms its place as an important member of the ABB FlowMaster family”, concludes Harry Lawrence, Product Manager, DP Flow.