Sentinel LNG

Panametrics ultrasonicflow meter for cryogenic liquids
Panametrics introduces Sentinel LNG, a new addition to our series of advanced ultrasonic flow meters. Sentinel LNG
demonstrates new levels of performance, reacts to changes in flow rate with incredible speed and accuracy, and isbased on proven technologies. Sentinel LNG extends the use of ultrasonic technology into cryogenic applications formeasuring liquefied natural gas (LNG) with unbeatable performance, reliability and safety.

Benefits

Applications• Improved performance, reduced maintenance anddynamic flow measurement for cryogenic liquids• Liquefied Natural Gas (LNG)• Fully welded construction with no moving parts• Ultrasonic transducers protected from cryogenic
temperatures using Bundle Waveguide™ Technology• Full bore design, zero pressure drop
• High accuracy to overcome limitations of tank level
gauging• Robust Path Configuration™ through extensive use of CFD(Computational Fluid Dynamics)• Cryogenic fluid allocation• Custody transfer• Marine Cargo Verification

Sentinel LNG design
The design philosophy behind Sentinel LNG was simple;
building a reliable flow meter to overcome the accuracy
limitation of LNG tank level measurement. Sentinel LNG isan ultrasonic flow meter with a fully welded constructionthat has no moving parts. The acoustic transducers areplaced outside the cryogenic liquid to avoid any long-term
degradation due to temperature. The design is full bore; as aresult, the pressure drop over the meter is simply equal to asection of pipe with the same length.

Advanced electronics
Sentinel LNG measures flow using advanced digital-signal
processing and improved algorithms that enable the meter
to measure flow with an exceptional response speed.
Sentinel LNG packs significant power in a simple package
available with several standard output options. Customer
wiring is kept in a separate location for safety. It can bemounted on the flowcell section or can be mounted up to
50 ft (15 m) away. Full access to cable connections is still
possible even when mounted directly to a wall.

Before Sentinel LNG was ever tested on a calibration loop,
the meter was already extensively tested in the virtual world.
Computational Fluid Dynamics (CFD) was used to simulatedifferent path configurations under different flow scenarios.

XZ-0.0665

00.06650.08020.2265

CFD simulation of acoustic port effects under highly turbulent flow

Measuring the volume of LNG in a tank is more than justmeasuring the level of the (boiling) LNG inside the tank. The
temperature in the tank might not be constant, causing
density variation. Corrections need to be made for tankexpansion caused by the weight of the LNG inside. In caseof level measurement on a ship, a pitch or even movementbecause of wave motion may require compensation.
By making a direct volume measurement, Sentinel LNG
overcomes all these additional sources of uncertainty.

The bundle waveguide technology acts as a buffer between
the transducer and the flowing cryogenic liquid. These buffer
assemblies use waveguide bundles to efficiently concentrate
a greater amount of transducer ultrasonic signal into theprocess. At the same time, the bundles act as a buffer toprotect the transducer from the cryogenic temperatures.
The buffer is an all-metal construction with no moving parts.
As a result, transducers can be safely removed from service
without opening the pipeline. An insertion mechanism or
expensive valves are not required.

Robust path configuration™

-0.0802

Limitations of tank level gauging

Bundle waveguide technology™

Full diagnostic capability can be checked locally on thedisplay, remotely by PC or output via a variety of digitalinterfaces for continuous verification and preventative
maintenance.

Z = -0.2265(m)CFD allowed us to test different ultrasonic pathconfigurations under highly turbulent flow regimes thatare typically seen in LNG measurements. Only after CFD
simulation provided the optimal path configuration, Sentinel
LNG was tested in a calibration loop to prove the CFD results.

Water calibration

Advanced electronics

The Sentinel LNG meter is equipped with time tested
correction curves that can translate a water calibration intohigh accuracy performance at cryogenic temperatures.

Sentinel LNG has advanced digital signal processors thatpack significant power in a simple package. Several output
options are standard. The electronics can be mounted on theflowcell section or up to 300 feet away. Cable connections
can easily be accessed, even when the meter has been
mounted to a wall. HART is standard on all meters. Local
diagnostics can be done via magnetic contacts through theglass, or by using the USB connection and our PanaView™
software.

Active temperature compensation™
Ultrasonic flow meters use transit time to determine the liquid
or gas flow in a pipeline. Measured transit time consists not
only of the time the ultrasonic signal spends in a fluid; it also
consists of a portion of “dead time,” being the time that theelectrical signal is converted into an acoustical signal andthe time the acoustic signal travels inside the transducer. To
allow for the utmost accuracy, Sentinel LNG uses pulse echo
to actively measure the dead time. By sending a pulse andmeasuring its reflection at the end of the transducer, thedead time is measured in real time rather then using a presetvalue. Sentinel LNG guarantees a flow measurement of thehighest accuracy.

Tw (”dead time” in buffer)
Tw (”dead time” in buffer)

PanaView™ for diagnostics

Tf (time in fluid)

BufferBWT Transducer
BufferTransit-timeflow measurement technique
Tf (time in fluid)

PanaView software facilitates communication between a PC
and the Sentinel LNG flow meter. This software monitors theSentinel flow meter to provide a secure and comprehensive
check on the meter configuration with a full audit trail. It also
allows live flow readings and tracking of flow diagnostics.

BWT Transducer

Active flow compensation

Fluctuations in temperature, especially in cryogenic
applications, can affect flow accuracy. These fluctuations
change the characteristics of the fluid traveling through thepipe, flowcell dimensions and the acoustic characteristics ofthe flow meter. Based on a live temperature input, Sentinel
LNG monitors the application temperature and calculates
the changes in the flowcell dimensions. The transducer’stransit time signal changes relative to temperature. Sentinel
LNG’s SEN898 electronics actively measure the transducer
transit time signal to ensure accurate overall transit timemeasurement. The meter automatically and continuously
makes adjustments as the application and ambientconditions change to ensure accurate measurement without
user intervention.
Example of PanaView display

Dimensions and weights

CA

Weights are based on stainless steel.

Dimensions and weights in English units
DiameterFlangeA (in)

150#
4300#
600#

68

10

12

14

16

18

20

24

Dimensions and weights in metric units

C (in)

Weight (lb)

20

23.49

150

20

23.99

178

20

24.36

202

150#

22

25.76

211

300#

24

26.51

268

600#

26

27.26

150#

26

27.59

300#

28

28.34

346

600#

30

29.09

150#

28

29.84

300#

30

30.59

492

DiameterFlangeA (mm)C (mm)

Weight (kg)

150#
4300#

508

597

68

508

609

81

600#

508

619

92

150#559

654

96

300#

610

673

121

341

600#

660

692

155

271

150#

660

701

123

300#

711

720

157

457

600#

762

739

207

371

150#

711

758

168

300#

762

777

223

6

8

10

600#

32

31.84

746

600#

813

809

339

150#

30

32.59

483

150#

762

828

219

300#

32

33.34

688

300#

813

847

312

600#

36

34.09

967

600#

914

866

438

150#

36

34.09

798

300#

38

35.09

1090

600#

40

35.46

150#

38

36.84

12

150#

914

866

362

300#

965

891

494

1352

600#

1016

901

613

989

150#

965

936

463
618

14

300#

40

37.84

1361

300#

1016

961600#

42

38.59

1788

600#

1067

980

811

150#

38

37.84

1067

150#

965

961

484

300#

40

39.34

1542

300#

1016

999

700

600#

44

39.96

2097

600#

1118

1015

951

150#

46

41.25

1438

150#

1168

1048

646

300#

1219

1086

962

600#

1270

1105

1280

300#

48

42.75

2141

600#

50

43.50

2847

150#

48

44.59

2010

300#

50

46.59

2976

600#

52

47.09

3985

16

18

20

24

150#

1219

1133

912

300#

1270

1183

1350

600#

1321

1196

1808

Specifications
Performance
Fluid types
Liquid hydrocarbons
Flow measurement
Correlation transit time mode
Accuracy< ± 0.25% of measured volume for flow rates between
2 and 30 ft/s (0.5 and 10 m/s).
Repeatability<±0.02%
Zero stability< 0.007 ft/s (0.002 m/s)
Process temperature-200° to +120°C (-328° to 248°F)
Ambient temperature-40° to +60°C (-40° to 140°F)
Storage temperature-40° to +80°C (-40° to +176°F)

Meter body
Path configuration
Four-path Robust Path Configuration™
Meter body materials

Electronics
Electronics enclosure material
Four-path Robust Path Configuration™
Dimensions• Weight 25 lb (11.5 kg)• Size (lxhxd): 13x11x9 in (33x27x23 cm)• Stainless steel A182, Gr 304/304L

Environmental protection
IP66

Others on request.

Power supply• Stainless steel A182, Gr 316/316L
Pipe sizes• 100 to 240 VAC

Others on request.

Power consumption< 20 watt• 4 in (100 mm) to 36 in (900 mm)
Flange ratings• 150 #

• 300 #
Others on request.

• 12 to 32 VDC

DisplayHigh contrast 128 x 64 pixel graphical display with LED
illumination

Pipe schedules

Outputs• 40S• Two alarm relays• 10S• Two frequency/pulse outputs optically isolatedfrom DC• STD• One 4/20 mA output with HARTOthers on request

PED compliance
PED Cat III, module H
Installation requirement
Meter must be installed with 20D straight piping upstream
and 5D straight piping downstream. Inlet and outlet piping ID
must meet meter ID.
Pressure, temperature and density connections must be
located in the downstream piping. The 20D upstream piping
must be free of any nozzles that could disturb the flow profile.

InputsTwo 4/20 mA and one 100 ohm RTD input for density, pressure
and temperature input (option). Three 4/20 mA inputs fordensity, pressure and temperature input (option).
Digital interfaces• HART over 4/20 mA output• PanaLink over RS232/485/USB• Modbus over RS232/485 (option)

Hazardous area certifications• USA/Canada: Class 1, Div 1, groups B, C, & D• Europe: ATEX II 2 G, Ex de IIC (Ex d IIC as option)• IEC Ex: Ex de IIC (Ex d IIC as option)
CE compliance• 2004/108/EC EMC Directive• 2006/95/EC LVD

Flow computer functionality
Integrated flow computer with full P and T volume corrections
according to API 11.1
Flow ranges
0.5 m/s

10 m/s

0.5 m/s

10 m/s

0.5 m/s10 m/s

Nominal diameter

1.69 ft/s

33 ft/s

1.69 ft/s

33 ft/s

1.69 ft/s

33 ft/s

inmm(m3/h)(m3/h)

(GPM)

(GPM)

(BBL/h)(BBL/h)

4

100

15

280

66

1230

94

1760

6

150

33

630

145

2770

207

3960

8

200

58

1130

255

4980

364

7120

10

250

91

1800

400

7900

873

11300

12300

131

2500

580

11000

825

15700

14350

179

3500

790

15400

1130

22000

16

400

233

4500

1030

19800

1470

28300

18

450

296

5700

1300

25100

1860

35900

16

500

365

7000

1600

30800

2300

44000

24600

525

10000

2310

44000

3300

63000

Typical flow rates for 0.5 m (19.6 in) per second and 10 m (393 in) per second are listed above. The Sentinel LNG is a fullbore meter and the flow range is a function of the pipe and not the meter itself.

Sentinel electronics SEN898 ordering information
SEN898SEN 898 electronics for custody transfer measurement
Feature 1: Power
1
100 to 240 VAC operating voltage
2
12 to 32 VDC operating voltage		Feature 2: Inputs		0None (not possible for LNG due to active temperature compensation)		1
One 100 ohm RTD input, Two 4-20mA inputs		2
Three 4-20mA inputs			Feature 3: Communications			0None			1Modbus RTU over RS232/RS485				Feature 4: Flow computer				0None (not possible for LNG due to active temperature compensation)				APIAPI correction of volume per API Chapter 11.1 (for LCT only, 3 inputs required)				LNGActive compensation for tube contraction (for LNG only, 3 inputs required)					Feature 5: Explosion proof					1USA/CAN explosion proof, Class 1, Div 1, groups B, C, D					2European flameproof , II 2G Ex d IIC					3European flameproof increased safety, II 2G Ex de IIC						Feature 6: Electronics mounting						LLocal Mounting, if ordering with SEN-LCT or SEN-LNG						RRemote Mounting, if ordering with SEN-LCT or SEN-LNG						SStand with remote mounting, cable length selectable (Max. 300 ft or 91 m)							0None							SSpecial

SEN898Sentinel LNG liquid custody transfer flow meter
SEN898Sentinel Liquid Custody Transfer Flow Meter
Feature 1: Diameter44” flowspool with RF flanges acc to ASME B16.5 (See Flow Rates table for metric conversion)
66” flowspool with RF flanges acc to ASME B16.5
88” flowspool with RF flanges acc to ASME B16.51010” flowspool with RF flanges acc to ASME B16.51212” flowspool with RF flanges acc to ASME B16.51414” flowspool with RF flanges acc to ASME B16.51616” flowspool with RF flanges acc to ASME B16.5
1818” flowspool with RF flanges acc to ASME B16.5
2020” flowspool with RF flanges acc to ASME B16.5
2424” flowspool with RF flanges acc to ASME B16.5
2828” flowspool with RF flanges acc to ASME B16.47
3030” flowspool with RF flanges acc to ASME B16.47
3232” flowspool with RF flanges acc to ASME B16.47
3636” flowspool with RF flanges acc to ASME B16.47		
Feature 2: Pressure class		150150 lbs pressure rating		300300 lbs pressure rating			Feature 3: Material			304Stainless steel, A182 Grade 304/304L			316Stainless steel, A182 Grade 316/316L				Feature 4: Schedule				10SSchedule size 10S				40SSchedule size 40S				STDSchedule size STD				SSpecial					Feature 5: Design criteria					AASME B31.3					PASME B31.3 with PED approval						Feature 6: Electronics mounting						SRemote mounting, cable length selectable (max 300 ft or 91 m)							Feature 7: Material certs							0None							1Material certs							2Material certs with EN 10204 3.1 inspection certificate								Feature 8: NACE requirements								0None								1NACE MR0175								2NACE MR0103									Feature 9: Special requirements								0None									SSpecialSEN898

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BHCS38691 (12/2020)

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