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UK Central Acquisition Terminal Service

A primary use of flow meter verification systems (powered by diagnostic systems) is to assure the flow meter is operating correctly. Use of a verification systems facilitate ‘Condition Based Maintenance’ (‘CBM’) instead of expensive, time consuming, hazardous ‘Routine Scheduled Maintenance’ (‘RSM’). CBM reduces both maintenance cost and staff exposure to hazardous areas.
Prognosis was tested at the UK Central Acquisition Terminal Service (‘CATS’) in Teesside, England. The UK regulator attended. The meter was a 16”, 0.6β orifice meter. Initial results showed the meter to be operating correctly (see Figure 1). The metering staff then deliberately induced various orifice meter problems.

Figure 2 shows the result of keypad entry geometry error, where the orifice bore of 8.195” was erroneously entered as 8.295” inducing a +2.8” flow prediction bias.

Figure 3 shows the result of the wrong DP transmitter in a stack (i.e. different ranged DP transmitters) being read. The correct primary DP of 17.5 kPa is read by thanover-ranged DP transmitter showing its maximum 15 kPa. The DP error indices a -7.1% flow prediction bias.

Figure 4 shows the result of the plate being installed backwards. As the plate has a bevel on the back face, this changes the meter performance. This induces a -15% flow prediction bias.

Figure 5vshows the result of the plate sharp edge becoming worn. This changes the meter performance. The wear tested induced a -2% flow prediction bias.