1. INTRODUCTION TO ELECTRONIC INSTRUMENTATION
Chapter 5 INTC 1305 – 01
FLOW
Vern Wilson

2. Review of Chapter 4 – Level
Innage/outage
Floats
Interface
Meniscus
Density and head

3. FLOW MEASUREMENTS
Chapter 5

4. Pipeline Meter Run
Pipeline Meter Run #117 avi

5. Gas Separator

8. Summary of Flow – These instruments measure FLOW Fluid in motion
Always from hi to lo p
Molecules continually change
Laminar - streamline
Turbulent
Obstructions mess up smooth flow
Usually turbulent flow is consistent

9. Reynolds Number Identifies type of flow – turb or lam
R = v x d x ϱ / μ
v = velocity
d = diameter
ϱ = density
μ = viscosity
> 4000 = turbulent
> 10,000 = fully turbulent
< 2,000 = laminar
Between 2,000 and 4,000 = transient

10. Flow Measurements Positive Displacement Percentage flow
Measures absolute volumes
Uses chambers of known volume
Percentage flow
Based on known flow at 100%
Volumetric Flow
GPM
MCFD
Mass Flow
Pounds per time

11. Flow Sensing Differential Pressure Bernoulli – page 109
As velocity increases the static pressure of the fluid decreases
Flow devices: Orifice (differential flow meters), Venturi, Flow Nozzles, pitot tubes, Annubar tubes, rotameters, electromagnetic meters, turbine meters, mass flow meters

12. ORIFICE PLATES Simple pressure drop Flat upstream – bevelled downside
Set in tapped flanges

13. Orifice Plates

14. FLOW PATTERN THROUGH ORIFICE

17. VENTURI TUBES – 5.3.2 Higher cost but lower op costs
Smooth cone shaped
As speeds increase in the throat the pressure is reduced according to Bernoulli

18. Venturi Tube

19. FLOW NOZZLE 5.3.3 Extended tapered inlet Can be inserted into a flange
Allow higher flow then orifice plates - twice
Can handle slurries
Less $ than venturi but more than orifice

20. Flow Nozzle

21. PITOT TUBES 5.3.4 Measures impinging pressure
Disadvantage – measures flow at only one point
Can’t measure laminar flow
ANNUBAR or MULTI PORT
Pitot with several ports

22. Pitot Tube

23. ROTAMETERS Based on gravity and impinging pressure
Tapered flow tube with a float
Flow tube calibrated to flow
Only give an estimate of flow
Float can be magnetized inside steel tube
Designed for specific small range

24. Rotameter

25. ELECTROMAGNETIC METER
Or Magmeters – no metal in body
Measures electrically conductive liquids
Generally water based
Obstruction free – noninvasive
Food and drug use
Based on Faraday’s law of induction – an electrical potential is produced when a conductor moves at a right angle through a magnetic field

27. TURBINE METER Flow tube with free spinning turbine
One blade is magnetic
Induction pick up coil
Each pulse indicates a rotation of the turbine
Simply multiply a K factor times the number of sensor pulses

28. Turbine Meter

31. MASS FLOW METER CORIOLIS METER
They measure density through temperature and pressure
Tube vibrates and twists giving a velocity difference which is converted to flow

32. DIFFERENTIAL (D/P) TRANSMITTER
Most common
Responds to pressure
Flow is proportional to square root of dp

33. MEASUREMENT
FLOW MEASURED IN:
GPM
POUNDS PER MINUTE

34. GPM EXERCISE
An injection program requires 100 barrels of injection fluid per day.
How many GPM is equal to 100 barrels per day?
First: There are 42 gallons per barrel
Second: Convert to GPM

35. POUNDS PER MINUTE EXERCISE
We are pumping mud that weighs pounds per gallon at 4 barrels per minute.
How many pounds per minute are we pumping?
First: Determine how many pounds are we pumping – 4 barrels = 42 gals/barrel
Second: Determine how many pounds per minute.

36. Orifice Chart 0.500 x 4” Temperature 95ºF Gravity = 0.73 Fb = 50.23
Fpb =
Ftb =
Fg =
Ftf = 0.968
Fr =
Fpv =

37. Orifice Chart C’ = 62.22 3 PM Friday 3 PM Saturday Hw = 68”
Ps = 220 psig
Q = C’√hw*Ps
Q = *
√68*( )
= 7860 CuFt/Hr
189 MCFD

38. Handbook

39. F Factors – Orifice Coefficient Fb

40. Fpb Ftb Fg

41. Orifice Chart C’ = 62.22 1 PM Tuesday 1 PM Wednesday Hw = ” Ps = psig
Q = C’√hw*Ps
Q = *
√ *( )
= CuFt/Hr
MCFD