WATER DRAW CERTIFICATION - Main Line Measurementdraw+presentation.pdfThis presentation will explain: •What a water draw is •Why they are important ... solenoid controlled valve

WATER DRAWCERTIFICATION

C E R T I F I E D C A L I B R AT I O N SCopyright 2016 Certified Calibrations, Inc.

Copyright 2016 Certified Calibrations, Inc.

This presentation will explain:• What a water draw is • Why they are important• How they are performed


To understand what a water draw is, let’s begin by describing why it is required.

P R O V I N G A N D P R O V E R SH O W P R OV E R S C O R R E C T F O R A C C U R A C Y


FLOW MEASUREMENT

Typical setup would include:

A. Pipe with flowing product

B. Pressure

C. Temperature

D. Flow Meter

E. Flow Computer


AB C

D

E

FLOW MEASUREMENT

The flow computer reads information from the temperature transmitter, pressure transmitter and flow meter to calculate a corrected flow rate


A B CD

E

Calculate Flow= 3200/BBLs/Hr.

WHAT IS A PROVE?

A prove is a procedure that validates a measurement system against a known, calibrated volume.


WHAT IS A PROVER?

A prover is a device with a precise, calibrated volume used to validate precision and correct for accuracy in a measurement system.


WHAT IS A PROVER?

A prover is a device with a precise, calibrated volume used to validate precision and correct for accuracy in a measurement system.


Calibrated Volume

WHAT IS A PROVER?

Detector switches are activated as a displacer passes through a calibrated section of the prover — enabling the flow computer to calculate the volume.


WHAT IS A PROVER?

Detector switches are activated as a displacer passes through a calibrated section of the prover — enabling the flow computer to calculate the volume.


DetectorSwitch

DetectorSwitch

Displacer

WHAT IS A PROVER?

When the displacer triggers the first detector switch a signal is sent to the flow computer to start counting meter pulses.


A B CD

E

WHAT IS A PROVER?

The second detector switch signals the flow computer to stop counting meter pulses and calculate the total volume between detector switches


A B CD

E

Calculate Volume = 499.905 Gallons

WHAT IS A PROVER?

Any difference between the calculated volume and the known prover volume is used to generate a correction factor (Meter Factor)


Prover Volume = 500 GallonsCalculated Volume = 499.905

Meter Factor = 1.0002

WHAT IS A PROVER?

This Process is then repeated 10 consecutive times or 5 roundtrips to establish a .050% repeatability between runs.


A B CD

E

WHAT IS A PROVER?



A B CD

E

WHAT IS A PROVER?



A B CD

E

WHAT IS A PROVER?



A B CD

E

PROVER CALIBRATION

Because provers are mechanical devices –subject to wear and tear (as well as many other factors) – they need to be recalibrated and certified periodically.


S O , W H AT “ P R O V E S ” T H E P R O V E R ?C A L I B R AT I N G P R OV E R S


WAT E R D R AWWAT E R D R AW P R OV E R C A L I B R AT I O N A N D C E R T I F I C AT I O N


THE FOLLOWING IS A SUMMARY.FOR MORE INFORMATION,PLEASE REFER TO

API CHAPTERS 4.9.1, 4.9.2


WATER DRAW SYSTEM HARDWARE

A. Water Tank

B. Pump

C. Prover

D. Flow Meter

E. Pressure Gauge


A

C

D

E

B

WATER DRAW SYSTEM HARDWARE

F. Bypass Valve

G. Test Measure Valve

H. NIST Certified Test Measure

I. Sight Glass

J. Discharge


F

G

H

I

J

NIST CERTIFIEDTEST MEASURESConstruction: Built to N.I.S.T. 105-3 Standards and API Chapter 4.7

Calibration: Certified using standards traceable to the National Institute of Standards and Technology


NIST CERTIFIEDTEST MEASURES

A.Fill Tube

B. Neck

C. Sight Glass and Scale

D. Spirit Level

E. Tank

F. Discharge

A

B C

E

F

D


WATER DRAW SYSTEM CONTROL

A. Displacer

B. Prover Detector Switches

C. PLC

D. Bypass Solenoid

E. Test Measure Solenoid


C

D

AB

E

WATER BYPASS

Water is circulated through the system (bypassing the test measure) to stabilize Temperature and remove all air before calibration.


WATER BYPASSThe main bypass valve is closed and a solenoid controlled valve is opened as the displacer is moved into position just before the 1st detector switch .


PROVER PRESSURE READING

A prover pressure reading is taken before calibration begins.


33 PSI

WATER BYPASS

When the prover detector switch is activated, the solenoid valve instantly closes—stopping all flow.


X

FILL TEST MEASURE

The main test measure fill valve is opened to start the calibration process.


FILL TEST MEASUREAs the displacer makes its way through the prover pipe, the test measure is filled with water until it reaches the sight glass.

A prover temperature reading is made 1/3 of the way during the calibration.


TemperatureReading:69.0 F

FILL TEST MEASUREAs the displacer makes its way through the prover pipe, the test measure is filled with water until it reaches the sight glass.

A prover temperature reading is made 1/3 of the way during the calibration.


FILL TEST MEASURE

The main test measure fill valve is closed allowing only the solenoid controlled valve to flow.


FILL TEST MEASURE

When the displacer triggers the second detector switch, the solenoid instantly stops flow into the test measure.


X

FILL TEST MEASURE

When the displacer triggers the second detector switch, the solenoid instantly stops flow into the test measure.


INTERFACE INVENTORYAfter the fill solenoid stops flow into test measure. The displacer continues into the launch chamber for temperature stabilization.


FILL TEST MEASURE

Using the sight glass and scale. The total volume delivered to the test measure is recorded.


Read bottom of meniscus

FILL TEST MEASURE

Using the sight glass and scale. The total volume delivered to the test measure is recorded.


500 Gallons+ 5 in3

TEMPERATURE READING

A temperature reading on the test measure is taken as water is discharged from the measure.

An average temperature sample of at least 1/3 of the total measure volume is required.


70.1F

FINAL DRAIN TIME

The drain valve must remain open a full 30 seconds after main flow has discharged from a bottom drain measure before closing the drain valve.


BI-DIRECTIONAL PROVERS

The process is repeated in the reverse direction for bi-directional provers providing a round-trip volume.


E S TA B L I S H I N G R E P E ATA B I L I T Y

The process is then repeated again at a different flow rate to check the integrity of the prover.



The process is then repeated again at a different flow rate to check the integrity of the prover.



Finally the process is completed a third time at the original flow rate to establish repeatability.

API requires all collected values to vary less than 0.020% for a valid water draw calibration



Finally the process is completed a third time at the original flow rate to establish repeatability.

API requires all collected values to vary less than 0.020% for a valid water draw calibration


C A L C U L AT I O N S

BMVA in3-Base Measured Volume (Adjusted)

CTDW- Corrected Water Density Effect

CCTS- Corrected compositional Temperature of Steel

WD-Water Draw

WDZB-Water Draw with Prover Dimensional Variation Effects


BMVA in3 CTDW CCTS WD WDZB

115505.0000 .999976 1.000084 115511.9301 115494.4899

Prover Volume= 499.976 Gallons

(one way)

TEST MEASURES500 Gallon (X2)

Tolerance = 5.0in3

200 Gallon

Tolerance = 1.0in3

100 Gallon

Tolerance = 1.0in3


5 Tbsp. 1Tbsp. 1Tbsp.

TEST MEASURES50 Gallon

Tolerance = 0.5in3

30 Gallon

Tolerance = 0.25in3

15 Gallon

Tolerance = 0.1in3


½ Tbsp. ¼ Tbsp. 1/10 Tbsp.

TEST MEASURES5 Gallon

Tolerance = 1.0in3

2 Gallon

Tolerance = 0.5in3

1 Gallon

Tolerance = 0.1in3


1 Tbsp. ½ Tbsp. 1/10 Tbsp.


Documents

WATER DRAW CERTIFICATION - Main Line Measurementdraw+presentation.pdfThis presentation will explain: •What a water draw is •Why they are important ... solenoid controlled valve