Flow Meter Understanding and Type of Flowmeters

FLOWMETER

1. Sense Services Sdn.Bhd. FLOW METERS 1 Flow Meters Sense Services Sdn. Bhd.

2. Flow meters general Primary element of the metering system. Measure and quantify liquid hydrocarbon flowing through the meter runs. Selection of flow meter depending on the flow rate, range ability(turndown), fluid viscosity, pressure drop, wax content and the corrosives properties. Various type of flow meters choices to choose from i.e. PD meters, Turbine meters, Ultrasonic meters, Mass meters and etc. Turbine meters – most commonly and widely used flow meter. 2 Flow Meters Sense Services Sdn. Bhd.

3. Turbine meter Two types of turbine meters Conventional rotor meter Helical or multi viscosity meter 3 Flow Meters Sense Services Sdn. Bhd.

4. Operating principle Theory: Inferred Volume Throughput = Fluid Velocity x Area ( Q = V x A) Where fluid velocity is proportional to the rotor velocity ( Vf:Vr ) 4 Flow Meters Sense Services Sdn. Bhd.

5. Signal generation 5 rotor revolution Rim type rotor Bearing Buttons of Paramagnetic Material Pickup coil Flow Meters Sense Services Sdn. Bhd.

6. Preamplifier 6 70 mV Peak to Peak Sinusoidal 0 to 24V dc Square Wave Output to Flow Computer Input from Turbine meter (pickup coil) Preamplifier Flow Meters Sense Services Sdn. Bhd.

7. Meter Performance Meter Performance govern by these parameters “ K” Factor = Pulses / Unit Volume (Determined by Proving ) Meter Factor = ratio of meter volume to true volume (Determined by Proving) Repeatability = Variation in “K” Factor or Meter Factor at a Given Flow Rate Flow Range = Max Flow to Min Flow Turn Down = Flow Range Expressed as a Ratio, e.g. 10:1 Shown Linearity (%) = Over Flow Range Stability = Accuracy Over a Long Period of Time Linearity =   Variation of K factor (pulse/m 3 ) that lies within a specified range 7 Flow Meters Sense Services Sdn. Bhd.

8. Performance CONTROL Measurement inaccuracy can be the result of equipment performance or human error. Accurate fluid measurement requires continuous monitoring to determine if the systems, equipment and procedures are operating within the acceptable limits. This can be done by the use of Control Charts. 8 Control Chart Example Flow Meters Sense Services Sdn. Bhd.

9. Meter factor control Chart Accurate measurement of product is critical to improving the measurement of actual Loss and Gain. Essential of accurate measurement are: A properly functioning meter and an accurate Meter Factor(MF) Control Charts used to evaluate a meter’s performance and asses the validity of meter factors. Control charts contain a plot of meter factors, “control limits” and a “mean”. Meter factors can be tested by comparing them for consistency with historical data. 9 Flow Meters Sense Services Sdn. Bhd.

10. Meter factor control Chart Proving data collected from various meter proving that make up a chart . 10 Flow Meters Sense Services Sdn. Bhd.

11. Meter factor control Chart 11 Control Chart Sample Flow Meters Sense Services Sdn. Bhd.

12. Performance CONTROL chart (CONT.) Control charts can be used in the case of MFs to evaluate a meter’s performance and to assess the validity of meter factors. An MF control chart contains a plot of meter factors, “control limits”, and a “mean”. Meter factors can be tested by comparing them for consistency with historical data . 12 Flow Meters Sense Services Sdn. Bhd.

13. Conventional Turbine Meter Construction - 3 basic assemblies Meter housing Internal assemblies a. Open bladed rotor b. Rimmed rotor 3. Pulse pick-up assemblies 13 Flow Meters Sense Services Sdn. Bhd.

14. advantages Accuracy • Wide flow range • Small size and weight • Low cost of ownership • Wide temperature and pressure range 14 Flow Meters Sense Services Sdn. Bhd.

15. Disadvantages Needs flow conditioning • Requires back pressure control to prevent cavitation • Difficulty in metering high-viscosity liquids • Requires meter-mounted electronics • Susceptibility to fouling or deposits • Sensitive to viscosity changes 15 Flow Meters Sense Services Sdn. Bhd.

16. Meter performance Flow turndown range: Any flow range from 10% to 100% of maximum • Viscosity turndown range: Any viscosity ( cSt ) up to 2X the meter’s diameter in .) • Reynolds number: Greater than 50,000 • Measurement turndown range (MTR) vs. linearity MTR Linearity 10:1 +/- 0.15% 15:1 +/- 0.25 % 16 Flow Meters Sense Services Sdn. Bhd.

17. Helical ( Multi Viscosity T urbine M eter ) Why Helical Turbine Meters? • Helical turbine meters challenge the limits of traditional metering 17 Light Products Heavy Products Turbine Meters PD Meters Helical Turbine Meters Flow Meters Sense Services Sdn. Bhd.

18. Meter Construction 18 Flow Meters Sense Services Sdn. Bhd.

19. ROTOR DESIGN 19 Conventional Turbine M eter Helical Turbine Meter Flow Meters Sense Services Sdn. Bhd.

20. advantages Increases measurement range to higher viscosity crude oils • Reduces susceptibility to fouling and deposits • Less sensitive to viscosity changes Easy maintenance due to interchangeable cartridge Low maintenance due to use of best material 20 Flow Meters Sense Services Sdn. Bhd.

21. METER PERFORMANCE Flow turndown range: Any flow range from 10% to 100% of maximum • Viscosity turndown range: Any viscosity ( cSt ) up to 10X the meter’s diameter (in .) • Reynolds number: Greater than 20,000 • Measurement turndown range (MTR) vs. linearity MTR Linearity 40:1 +/- 0.15% 60:1 +/- 0.25 % 21 Flow Meters Sense Services Sdn. Bhd.

22. Flow conditioning Strainer, Valve, Elbows and Reducers etc cause swirl(improper flow pattern) that effect meter performance. Installation of flow straightener correct the flow profile. 22 Flow Meters Sense Services Sdn. Bhd.

23. Pressure effect 23 Pressure is measure by means of a pressure transmitter connected via impulse tubing to the meter runs and at the prover, of which the signal is then connected to the meter run and prover computer. This is for the measurement of the meter runs and prover pressure. Specifically for the correction of: CPLm – correction factor for the effect of pressure on liquid at meter. CPLp – correction factor for the effect of pressure on liquid at prover CPSp - c0rrection factor for the effect of pressure on prover material . which correct the flowing volume from operational condition to base condition of 101.5 kPa . or atm. Flow Meters Sense Services Sdn. Bhd.

24. Temperature effect Temperature is measure at the meter run by means of a temperature element connected to a transmitter then to the meter run’s and at the prover which is connected to the prover computer. This is for the measurement of the meter runs and prover temperature. Specifically for the correction of: CTLm – correction factor for the effect of temperature on liquid at meter CTLp – correction factor for the effect of temperature on liquid at prover CTSp - correction factor for the effect of temperature on prover material. which correct the flowing volume from operational condition to base condition of 15°C. 24 Flow Meters Sense Services Sdn. Bhd.