Turbine meters
At the Terasen Measurement patented facility, we’re able to test flow meters over a wide range of operating conditions using carbon dioxide (CO
) matched to true operating conditions. For high pressure testing, we match the Reynolds Number using the gas density of CO to that of Natural Gas in field conditions.
) matched to true operating conditions. For high pressure testing, we match the Reynolds Number using the gas density of CO to that of Natural Gas in field conditions.Calibration capabilities
| Flow range | 1,000 - 230,000 ACFH (30 - 6,500 m3/hr) |
| Pressure range (CO test medium) |
2" - 12" turbine meter 0 - 235 psig (0 - 1,620 kPa) equivalent pressure of 470 psi |
| Temperature range | 5°C - 35°C (41°F - 95°F) |
| Fluid type | CO or air |
| ANSI rating & size | ANSI 150, 300, 600 and meters sized NPS 2 to NPS 12 |
| Maximum reynolds number | 9,300,000 |
| Measurement uncertainty | +/- 0.27% |
| Reproducibility | +/-0.2% |
| Traceability | Traceable to international standards through NMI (Holland Metrology N.V.) |
| Meter Runs | Complete meter runs up to 22' (6.7m) by special arrangement |
A significant reduction in the margin of error
The dependency of turbine meters on Reynolds Numbers can have a severe impact on measurement accuracy. The key is to replicate actual operating conditions. Results obtained with traditional tests rely on air at atmospheric pressure. As a result, some measurements, and consequently calibration, are inherently inaccurate. By utilizing carbon dioxide (CO) at high pressures – in effect duplicating a range of true operating conditions – our high pressure testing process can significantly reduce the margin of error.Studies have shown that turbine meters need to be calibrated under in-service conditions for acceptable accuracy. The best calibration results are obtained by matching the in-service Reynolds Numbers and flow rates to the meter under test. For a true representation of how a meter will operate in the field it is recommended that it be tested at a higher pressure than atmospheric if is being used at higher pressures in the field.
Meters in low-pressure, low-flow applications operate at the lowest Reynolds conditions. Meter performance can change up to several percent when comparing low pressure test conditions (typically under 1-1.5 million Reynolds Numbers) to high pressure test conditions. Meters that are tested at lower flows relative to the meters Qmax (maximum pressure) and lower pressures (eg. Atmospheric) have the greatest loss in accuracy. Meters that operate at a higher Reynolds Number and tested at high pressure provide a more accurate calibration.
A significant benefit to both utilities and their customers
High Pressure Testing significantly advances industrial metering for gas utilities across North America and offers improvements to the accuracy of turbine meter testing with these benefits:- more accurate billing for turbine customers
- established credibility through third party verification
- immediate access, year round, to accurate test facilities
- faster turnaround times
- technical expertise
What is Reynolds Number?
Reynolds Number is a dimensionless ratio of inertial to viscous forces that takes into account the flow rate and physical properties of a fluid. It is proportional to flow rate and density and inversely proportional to meter diameter and viscosity.
What does the industry recommend?
AGA (American Gas Association) Report No 7, Measurement of Natural Gas by Turbine Meter recommends a turbine meter be calibrated close to its operating conditions in order to minimize measurement errors caused by pressure variation. Better results are achieved when testing near operating conditions.
ERCB (Energy Resources Conservation Board which regulates the oil and gas industry in Alberta) notes in Directive 17, 2.5.2.1, item 4 that meters with moving parts be proved “….at a pressure that is within the normal operating condition for that meter location.”
Remote testing witnessing
Customers can view their meter being tested remotely from anywhere in the world. For high pressure testing services on your turbine meter that require witnessing, this service will save you time, travel and expense costs. To arrange this service, please contact us to set this up. A time will be arranged for you to log in with an ID and password.
Once your remote witnessing of a test is arranged, you will receive an email a few days before with the test schedule, website address and log in information.