Armstrong AVF User manual

Armstrong AVF and AVI Vortex Meter
Installation and Operation Manual
359-EN V1.0
Please read and save
these instructions.

2Designs, materials, weights and performance ratings are approximate and subject to change without notice. Visit armstronginternational.com for up-to-date information.
Customer Notice for Oxygen Service
2
Notice to Users
Warning based on Electric Appliances Safety Control Act of Korea. This product should be handled as electromagnetic
radiation emitting equipment, and is intended for use by industrial dealers and end-users. It is not for residential use.
NIST Standard Reference Database 23, NIST Reference Fluid Thermodynamic and Transport Properties: REFPROP
Version 9.x. Standard Reference Databases are copyrighted by the U.S. Secretary of Commerce on behalf of the United
States of America. All rights reserved. No part of the database may be reproduced, stored in a retrieval system or
transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise without prior
permission.
Unless you have specifically ordered Armstrong’s optional O2cleaning, this flow meter may not be fit for oxygen
service. Some models can only be properly cleaned during the manufacturing process. Armstrong International is not
liable for any damage or personal injury, whatsoever, resulting from the use of Armstrong’s standard vortex meters for
oxygen gas.
Specic Conditions of Use
(ATEX/IECEx)
Contact Manufacturer regarding Flame path information.
Clean with a damp cloth to avoid any build-up of electrostatic charge.
The Armstrong AVF and AVI Vortex Flowmeters standard temperature option (ST) process temperature range is -40°C
to 260°C. The high temperature option (HT) process temperature range is -40°C up to +400°C.
AVF Vortex Flowmeters Process Temperatures
Tmax
(Process)
Temperature Class Value (Gas)
ST Version HT Version
80°C T6 85°C
95°C T5 100°C
130°C T4 135°C
195°C T3 200°C
260°C T2 300°C
400°C N/A 405°C

Designs, materials, weights and performance ratings are approximate and subject to change without notice. Visit armstronginternational.com for up-to-date information. 3
Table of Contents
Chapter 1 Introduction
AVF and AVI Vortex Mass Flow Meters.......................... 7
Using this Manual.......................................................... 7
Note and Safety Information ......................................... 8
Receipt of System Components ................................... 8
Technical Assistance ..................................................... 8
How the Pro-V Vortex Meter Operates .......................... 9
Velocity Measurement .................................................. 9
Vortex Shedding Frequency .......................................... 9
Vortex Frequency Sensing ............................................ 10
Flow Velocity Range ...................................................... 10
Pressure Drop ............................................................... 11
Minimum Back Pressure ............................................... 12
Temperature Measurement ........................................... 12
Pressure Measurement ................................................. 12
Flow Meter Configurations ............................................ 12
Multivariable Options .................................................... 13
Line Size / Process Conditions / Materials .................... 13
Flow Meter Electronics ................................................. 13
Chapter 2 Installation
Installation Overview ..................................................... 14
Flow Meter Installation Requirements .......................... 14
Unobstructed Flow Requirements ................................. 15
Series AVF In-Line Flow Meter Installation ................... 16
Wafer-Style Flow Meter Installation .............................. 17
Flange-Style Flow Meter Installation ............................. 18
Series AVI Insertion Flow Meter Installation ................. 19
Cold Tap Guidelines ....................................................... 20
Hot Tap Guidelines ........................................................ 21
Flow Meter Insertion ..................................................... 22
Installing Meters with a Compression Connection ........ 23
Installing Meters with a Packing Gland Connection ...... 25
Installing Meters (Packing Gland), No Insertion Tool ... 28
Adjusting Meter Orientation .......................................... 30
Display/Keypad Adjustment .......................................... 30
Enclosure Adjustment ................................................... 31
Loop Power Flow Meter Wiring Connections ................ 32
Input Power Connections ............................................. 32
4-20 mA Output Connections ....................................... 33
Pulse Output Connections ............................................ 34
Frequency Output Connections ..................................... 35
Optional Backlight Connections .................................... 35
Remote Electronics Wiring ........................................... 36
High Power Flow Meter Wiring Connections ................ 38
Input Power Connections ............................................. 38
4-20 mA Output Connections ....................................... 40
Frequency Output Connections ..................................... 41
Pulse Output Connections ............................................ 42
Alarm Output Connections ............................................ 44
Remote Electronics Wiring ........................................... 45
Optional Input Electronics Wiring ................................. 46
Optional Energy EMS RTD Input Wiring ....................... 46
Optional External 4-20 mA Input Wiring ....................... 47
Optional Contact Closure Input Wiring ......................... 48

4Designs, materials, weights and performance ratings are approximate and subject to change without notice. Visit armstronginternational.com for up-to-date information.
Table of Contents
Chapter 3 Operating Instructions
Flow Meter Display/Keypad ........................................................................ 49
Start Up ..................................................................................................... 50
Run Mode Screens .................................................................................... 50
Using the Setup Menus ............................................................................. 51
Programming the Flow Meter .................................................................. 52
Output Menu ............................................................................................ 53
Display Menu ........................................................................................... 55
Alarms Menu ........................................................................................... 56
Totalizer #1 Menu .................................................................................... 57
Totalizer #2 Menu .................................................................................... 58
Energy Menu ........................................................................................... 59
Fluid Menu ............................................................................................... 60
Units Menu .............................................................................................. 61
Time and Date Menu ............................................................................... 62
Diagnostics Menu .................................................................................... 63
Calibration Menu ..................................................................................... 64
Password Menu ....................................................................................... 65
Chapter 4 Serial Communications
HART™ Communications ........................................................................... 66
Wiring ...................................................................................................... 66
HART Commands with the DD Menu ...................................................... 68
HART Commands with Generic DD Menu ............................................... 73
MODBUS Communications ........................................................................ 76
Wiring ...................................................................................................... 76
Menu Items ............................................................................................. 77
Register Definitions ................................................................................. 79
BACNET™ MSTP Communications ............................................................ 86
BACNET MSTP Description ..................................................................... 86
Baud Rates on the MS/TP Bus ................................................................ 86
Supported BACnet Objects ...................................................................... 87
ANNEX - BACnet Protocol Implementation Conformance Statement ...... 93
Acronyms and Definitions ....................................................................... 99
Chapter 5 Troubleshooting and Repair
Hidden Diagnostics Menus ........................................................................ 100
Level One Hidden Diagnostics Values ........................................................ 102
Level Two Hidden Diagnostics Values ........................................................ 104
Analog Output Calibration .......................................................................... 105
Troubleshooting the Flow Meter ................................................................ 106
First Check Items ....................................................................................... 106
Record Values ............................................................................................ 106
Determine the Fault .................................................................................... 108
Symptom: Output at no Flow ..................................................................... 108
Symptom: Erratic Output ........................................................................... 108
Symptom: No Output ................................................................................. 109
Symptom: Meter Displays Temperature Fault ............................................ 110
Symptom: Meter Displays Pressure Fault................................................... 110
Electronics Assembly Replacement ........................................................... 111
Pressure Sensor Replacement (Series AVF Only) ...................................... 112
Returning Equipment to the Factory .......................................................... 112

Designs, materials, weights and performance ratings are approximate and subject to change without notice. Visit armstronginternational.com for up-to-date information. 5
Table of Contents
Figures continued
2-42 High Power Flow Meter Junction Box ................................. 45
2-43. Optional Energy EMS RTD Input Wiring ............................. 46
2-44. External 4-20 mA Input Wiring – External Power Supply ... 47
2-45. External 4-20 mA Input Wiring – DC Powered Meter ......... 47
2-46. External 4-20 mA Input Wiring – AC Powered Meter ......... 48
2-47. Optional External Contact Closure Input Wiring ................. 48
3-1. Flow Meter Display/Keypad .................................................. 49
4-1. Loop Powered Meter Wiring (HART) .................................... 66
4-2. DC Powered Meter Wiring (HART) ....................................... 67
4-3. AC Powered Meter Wiring (HART) ....................................... 67
4-4. RS-485 Wiring (MODBUS) ................................................... 76
5-1. Electronics Stack Sensor Connections ................................. 109
5-2. Remote Feed Through Board Sensor Connections ............... 109
5-3. Vortex Sensor Connector ..................................................... 109
5-4. Temperature Sensor Connector ............................................ 110
5-5. Pressure Sensor Connector ................................................. 110
Tables
4-1. Byte Order (MODBUS) ........................................................ 77
4-2. Register Definitions (MODBUS) .......................................... 80
Appendix A Product Specifications
Appendix B Approvals
Appendix C Flow Meter Calculations
Appendix D Glossary
Figures
1-1. In-Line Vortex Multi-Parameter Mass Flow Meter .................... 9
1-2. Measurement Principle of Vortex Flow Meters.......................... 9
1-3. Reynolds Number Range of the Pro-V ..................................... 11
2-1. Recommended Pipe Length Required for Installation .............. 15
2-2. Flange Bolt Torquing Sequence ................................................ 16
2-3. Wafer-Style Flow Meter Installation .......................................... 17
2-4. Flange-Style Flow Meter Installation ......................................... 18
2-5. Hot Tap Sequence .................................................................... 21
2-6. Insertion Calculation (Compression Type) ................................ 23
2-7. Flow Meter with Compression Type Fitting .............................. 24
2-8. Insertion Calculation (Meters with Insertion Tool) ................... 25
2-9. Flow Meter with Permanent Insertion Tool ............................... 26
2-10. Flow Meter with Removable Insertion Tool ............................ 27
2-11. Insertion Calculation (Meters without Insertion Tool) ............ 28
2-12. Display/Keypad Viewing Adjustment ...................................... 30
2-13. Enclosure Viewing Adjustment ............................................... 31
2-14. Loop Power Wiring Terminals ................................................ 32
2-15. DC Power Connections ........................................................... 32
2-16. Load Resistance Versus Input Voltage ................................... 33
2-17. Isolated Pulse Output Using External Power Supply .............. 34
2-18. Non-Isolated Pulse Output Using External Power Supply ...... 34
2-19. Isolated Frequency Output Using External Power Supply ...... 35
2-20. Non-Isolated Freq. Out. Using External Power Supply ........... 35
2-21. Backlight Using External Power Supply .................................. 35
2-22. Loop Power Volumetric Flowmeter Junction Box .................. 36
2-23. Loop Power Volumetric Flowmeter Junction Box Prior .......... 37
2-24. Loop Power Mass Flowmeter Junction Box ........................... 37
2-25. AC Wiring Terminals ............................................................... 38
2-26. AC Power Connections ........................................................... 38
2-27. DC Wiring Terminals .............................................................. 39
2-28. DC Power Connections ........................................................... 39
2-29. Load Resistance Versus Input Voltage ................................... 40
2-30. Isolated 4-20 Output Using External Power Supply ............... 40
2-31. Non-Isolated 4-20 Output Using Input Power Supply ............ 41
2-32. Isolated 4-20 Output Using Meter Power Supply (AC only).... 41
2-33. Isolated Frequency Output Using External Power Supply ...... 41
2-34. Non-Isolated Frequency Output Using Input Power Supply .... 42
2-35. Isolated Freq. Out. Using Meter Power Sup. (AC only) .......... 42
2-36. Isolated Pulse Output Using External Power Supply .............. 43
2-37. Non-Isolated Pulse Output Using Input Power Supply ........... 43
2-38. Isolated Pulse Output Using Meter Power Sup. (AC only) ..... 43
2-39. Isolated Alarm Output Using External Power Supply ............. 44
2-40 Non-Isolated Alarm Output Using Meter Power Supply .......... 44
2-41 Isolated Alarm Output Using Meter Power Sup. (AC only) ...... 45

6Designs, materials, weights and performance ratings are approximate and subject to change without notice. Visit armstronginternational.com for up-to-date information.
Warnings and Cautions
Warning!
Consult the flow meter nameplate for specific flow meter approvals before any hazardous location installation.
Hot tapping must be performed by a trained professional. U.S. regulations often require a hot tap permit. The
manufacturer of the hot tap equipment and/or the contractor performing the hot tap is responsible for providing proof
of such a permit.
All flow meter connections, isolation valves and fittings for cold/hot tapping must have the same or higher pressure
rating as the main pipeline.
For Series AVI insertion flow meter installations, an insertion tool must be used for any installation where a flow meter
is inserted under pressure greater than 50 psig.
To avoid serious injury, DO NOT loosen a compression fitting under pressure.
To avoid potential electric shock, follow National Electric Code or your local code when wiring this unit to a power
source. Failure to do so could result in injury or death. All AC power connections must be in accordance with published
CE directives. All wiring procedures must be performed with the power Off.
Before attempting any flow meter repair, verify that the line is not pressurized. Always remove main power before
disassembling any part of the mass flow meter.
Caution!
Calibration must be performed by qualified personnel. Armstrong International strongly recommends that you return
your flow meter to the factory for calibration.
In order to achieve accurate and repeatable performance, the flow meter must be installed with the specified minimum
length of straight pipe upstream and downstream of the flow meter’s sensor head.
When using toxic or corrosive gases, purge the line with inert gas for a minimum of four hours at full gas flow before
installing the flow meter.
For Series AVI insertion flow meter installations, the sensor alignment pointer must point downstream in the direction
of flow.
The AC wire insulation temperature rating must meet or exceed 85°C (185°F)

Designs, materials, weights and performance ratings are approximate and subject to change without notice. Visit armstronginternational.com for up-to-date information. 7
Chapter 1 Introduction
AVF and AVI Multi-Parameter Vortex Mass Flow Meters
Armstrong International’s AVF In-Line and AVI Insertion Vortex Flow Meters provide a reliable solution for process flow
measurement. From a single entry point in the pipeline, vortex meters offer precise measurements of mass or volumetric
flow rates.
Multi-Parameter Mass Flow Meters
Mass flow meters utilize three primary sensing elements: a vortex shedding velocity sensor, an RTD temperature sensor,
and a solid state pressure sensor to measure the mass flow rate of gases, liquids, and steam.
Meters are available as loop powered devices or with up to three 4-20 mA analog output signals for monitoring your
choice of the five process variables (mass flow, volumetric flow, temperature, pressure and fluid density). The Energy
Monitoring option permits real-time calculation of energy consumption for a facility or process.
Volumetric Flow Meters
The primary sensing element of a volumetric flow meter is a vortex shedding velocity sensor. Meters are loop powered.
The analog 4-20 mA output signal offers your choice of volumetric or mass flow rate. Mass flow rate is based on a
constant value for fluid density stored in the instrument’s memory.
Both the mass and volumetric flow meters are supplied with a local keypad/display which provides instantaneous flow
rate, total, and process parameters in engineering units. A pulse output signal for remote totalization and MODBUS
or HART communications are also available. Pro-V digital electronics allows for easy reconfiguration for most gases,
liquids and steam. The Armstrong AVF and AVI meters’ simple installation combines with an easy-to-use interface that
provides quick set up, long term reliability and accurate mass flow measurement over a wide range of flows, pressures
and temperatures.
Using This Manual
This manual provides information needed to install and operate both the AVF In-Line and AVI Insertion Flow Meters.
• Chapter 1 includes the introduction and product description
• Chapter 2 provides information needed for installation
• Chapter 3 describes system operation and programming
• Chapter 4 provides information on HART and MODBUS protocols
• Chapter 5 covers troubleshooting and repair
Appendix A - Product Specifications, Appendix B – Approvals,
Appendix C – Flow Meter Calculations, Appendix D – Glossary of Terms

8Designs, materials, weights and performance ratings are approximate and subject to change without notice. Visit armstronginternational.com for up-to-date information.
Installation
Note and Safety Information
We use note, caution and warning statements throughout this book to draw your attention to important information.
Warning!
This statement appears with information that is important to protect people and equipment from damage.
Pay very close attention to all warnings that apply to your application.
Caution!
This statement appears with information that is important for protecting your equipment and performance.
Read and follow all cautions that apply.
Note
This statement appears with a short message to alert you to an important detail.
Receipt of System Components
When receiving an Armstrong mass flow meter, carefully check the outside packing carton for damage incurred in
shipment. If the carton is damaged, notify the local carrier and submit a report to the factory or distributor. Remove
the packing slip and check that all ordered components are present. Make sure any spare parts or accessories are not
discarded with the packing material. Do not return any equipment to the factory without first contacting Armstrong
Customer Service.
Technical Assistance
If you encounter a problem with your flow meter, review the configuration information for each step of the
installation, operation and set up procedures. Verify that your settings and adjustments are consistent with factory
recommendations. Refer to Chapter 5, Troubleshooting, for specific information and recommendations.
If the problem persists after following the troubleshooting procedures outlined in Chapter 5, contact Armstrong
International, VERIS Flow Measurement Group at [phone]. When calling Technical Support, have the following
information on hand:
• the serial number (marked on the meter nameplate)
• the problem you are encountering and any corrective action taken
• application information (fluid, pressure, temperature and piping configuration)

Designs, materials, weights and performance ratings are approximate and subject to change without notice. Visit armstronginternational.com for up-to-date information. 9
How the Vortex Mass Flow Meter Operates
Velocity Measurement
The vortex velocity sensor is a patented mechanical design that minimizes the effects of pipeline vibration and pump
noise, both of which are common error sources in flow measurement with vortex flow meters.
The velocity measurement is based on the well-known Von Karman vortex shedding phenomenon. Vortices are shed
from a shedder bar, and the vortex velocity sensor located downstream of the shedder bar senses the passage of
these vortices. This method of velocity measurement has many advantages including inherent linearity, high turndown,
reliability and simplicity.
Vortex Shedding Frequency
Von Karman vortices form downstream of a shedder bar into two distinct wakes. The vortices of one wake rotate
clockwise while those of the other wake rotate counterclockwise. Vortices generate one at a time, alternating from the
left side to the right side of the shedder bar. Vortices interact with their surrounding space by over-powering every other
nearby swirl on the verge of development. Close to the shedder bar, the distance (or wave length) between vortices
is always constant and measurable. Therefore, the volume encompassed by each vortex remains constant, as shown
below. By sensing the number of vortices passing by the velocity sensor, the AVF or AVI flow meter computes the total
fluid volume.
Figure 1-2. Measurement Principle of Vortex Flow Meters
Figure 1-1. In-Line Vortex Multi-Parameter Mass Flow Meter
Armstrong AVF and AVI
Multi-Parameter Vortex Mass Flow Meters use a unique
sensor head to monitor mass flow rate by directly
measuring three variables–fluid velocity, temperature
and pressure.
The built-in flow computer calculates the mass flow
rate and volumetric flow rate based on these three
direct measurements. The velocity, temperature and
pressure sensing head is built into the vortex meter’s
flow body. To measure fluid velocity, the flow meter
incorporates a bluff body (shedder bar) in the flow
stream and measures the frequency of vortices created
by the shedder bar. Temperature is measured using
a platinum resistance temperature detector (PRTD).
Pressure measurement is achieved using a solid-state
pressure transducer. All three elements are combined
into an integrated sensor head assembly located
downstream of the shedder bar within the flow body.

10 Designs, materials, weights and performance ratings are approximate and subject to change without notice. Visit armstronginternational.com for up-to-date information.
How the Vortex Mass Flow Meter Operates
Vortex Frequency Sensing
The velocity sensor incorporates a piezoelectric element that senses the vortex frequency. This element detects
the alternating lift forces produced by the Von Karman vortices flowing downstream of the vortex shedder bar. The
alternating electric charge generated by the piezoelectric element is processed by the transmitter’s electronic circuit to
obtain the vortex shedding frequency. The piezoelectric element is highly sensitive and operates over a wide range of
flows, pressures and temperatures.
Flow Velocity Range
To ensure trouble-free operation, vortex flow meters must be correctly sized so that the flow velocity range through the
meter lies within the measurable velocity range (with acceptable pressure drop) and the linear range.
The measurable range is defined by the minimum and maximum velocity using the following table.
Gas Liquid
Vmin
Vmax
0.5 in
0.75 in
1 in
1.5 in and greater
5
√density (Lb/ft3)
175 ft/s
250 ft/s
250 ft/s
300 ft/s
1 ft/s
30 ft/s
30 ft/s
30 ft/s
30 ft/s
English p(lb/ft3)
Vmin
Vmax
DN15
DN20
DN25
DN40 and greater
6.1
√density (kg/m3)
53 m/s
76 m/s
76 m/s
91 m/s
0.3 m/s
91 m/s
91 m/s
91 m/s
91 m/s
Metric p(kg/m3)
The linear range is defined by the Reynolds number. The Reynolds number is the ratio of the inertial forces to the viscous
forces in a flowing fluid and is defined as:
Where:
Re = Reynolds Number
p = mass density of the fluid being measured
V = velocity of the fluid being measured
D = internal diameter of the flow channel
µ = viscosity of the fluid being measured
p V D
µ
RE =
ft/s
m/s

Designs, materials, weights and performance ratings are approximate and subject to change without notice. Visit armstronginternational.com for up-to-date information. 11
How the Vortex Mass Flow Meter Operates
Figure 1-3. Reynolds Number Range for the AVF and AVI vortex meters
The Strouhal number is the other dimensionless number that quantifies the vortex phenomenon. The Strouhal number is
defined as:
St = fd
V
Where:
St = Strouhal Number
f = frequency of vortex shedding
d = shedder bar width
V = fluid velocity
As shown in Figure 1-3, Armstrong vortex meters exhibit a constant Strouhal number across a large range of Reynolds
numbers, indicating a consistent linear output over a wide range of flows and fluid types. Below this linear range, the
intelligent electronics in the AVF and AVI meters automatically correct for the variation in the Strouhal number with the
Reynolds number. The meter’s smart electronics corrects for this non-linearity via its simultaneous measurements of the
process fluid temperature and pressure. This data is then used to calculate the Reynolds number in real time. Armstrong
vortex meters automatically correct down to a Reynolds number of 5,000.
Pressure Drop
The pressure drop for series AVI insertion meters is negligible. The pressure drop for series AVF in-line meters is defined
as:
∆P = .00024 PI V2English units ( ∆P in psi, PI in lb/ft3, V in ft/sec)
∆P = .000011 PI V2Metric units ( ∆P in bar, PI in kg/m3, V in m/sec).

12 Designs, materials, weights and performance ratings are approximate and subject to change without notice. Visit armstronginternational.com for up-to-date information.
How the Vortex Mass Flow Meter Operates
Minimum Back Pressure
A minimum back pressure is required to prevent cavitation in the vortex flow meter when installed in liquid applications.
Cavitation is a phenomenon wherein a liquid passing through a low pressure zone no longer can remain in the liquid
phase and therefore partially flashes (or “boils”) into its vapor phase. The resulting two-phase flow degrades the liquid
calibration accuracy. For some applications, a valve downstream of the flow meter may be required to increase the
pressure in the meter, thereby avoiding cavitation. The following equation defines the minimum back pressure to prevent
cavitation.
P = 2.9 ∆P + 1.3 PV
Where:
P = Minimum line pressure five pipe diameters downstream of the flow meter required to avoid cavitation (psia or bara).
∆P = Permanent pressure loss across the flow meter (psia or bara).
PV= Liquid vapor pressure at actual flowing conditions (psia or bara).
Temperature Measurement
Armstrong vortex flow meters use a 1000 ohm platinum resistance temperature detector (PRTD) to measure fluid
temperature.
Pressure Measurement
Armstrong vortex flow meters incorporate a solid-state pressure transducer isolated by a 316 stainless steel diaphragm.
The transducer itself is micromachined silicon, fabricated using integrated circuit processing technology. A nine-point
pressure/temperature calibration is performed on every sensor. Digital compensation allows these transducers to
operate within a 0.3% of full scale accuracy band within the entire ambient temperature range of -40°F to 140°F (-40
to 60°C). Thermal isolation of the pressure transducer ensures the same accuracy across the allowable process fluid
temperature range of -330°F to 750°F (-200 to 400°C).
Flow Meter Configurations
Armstrong Vortex Mass Flow Meters are available in two model configurations:
Series AVF in-line flow meter (replaces a section of the pipeline)
Series AVI insertion flow meter (requires a “cold” tap or a “hot” tap into an existing pipeline)
Both the in-line and insertion configurations are similar in that they both use identical electronics and have similar
sensor heads. Besides installation differences, the main difference between an in-line flow meter and an insertion flow
meter is their method of measurement.
For an in-line vortex flow meter, the shedder bar is located across the entire diameter of the flow body. Thus, the entire
pipeline flow is included in the vortex formation and measurement. The sensing head, which directly measures velocity,
temperature and pressure is located just downstream of the shedder bar.
Insertion vortex flow meters have a shedder bar located across the diameter of a short tube. The velocity, temperature
and pressure sensor are located within this tube just downstream of a built-in shedder bar. This entire assembly is called
the insertion sensing head. It fits through any entry port with a 1.875 inch minimum internal diameter.
The sensing head of an insertion vortex flow meter directly monitors the velocity at a point in the cross-sectional area of
a pipe, duct, or stack (referred to as “channels”). The velocity at a point in the pipe varies as a function of the Reynolds
number. The insertion vortex flow meter computes the Reynolds number and then computes the total flow rate in the
channel. The output signal of insertion meters is the total flow rate in the channel. The accuracy of the total flow rate
computation depends on adherence to the piping installation requirements given in Chapter 2. If adherence to those
guidelines cannot be met, contact the factory for specific installation advice.

Designs, materials, weights and performance ratings are approximate and subject to change without notice. Visit armstronginternational.com for up-to-date information. 13
How the Vortex Mass Flow Meter Operates
Multivariable Options
The AVF and AVI models are available with the following options: V1, volumetric flowmeter; V2, velocity and temperature
sensors; V3, velocity, temperature, and pressure sensors; E1 energy output options; E2, energy options with pressure;
V4, external pressure transmitter input.
Line Size / Process Connections / Materials
The AVF In-line model is built for line sizes ½ through 4 inch wafer or ½ through 8 inch flanged design using ANSI 150,
300, 600, PN16, 40, or 64 class flanges.
The AVI Insertion model can be used in line sizes 2 inch and greater and is built with a compression fitting or packing
gland design using 2 inch NPT, or 2 inch flanged connections (ANSI 150, 300, 600, PN16, 40, or 64 class flanges). The
packing gland design can be ordered with a permanent or removable retractor.
The AVF In-line model can be built with A105 carbon steel, 316L stainless steel, or Hastelloy C-276. The AVI Insertion
model can be built with 316L stainless steel or Hastelloy C-276.
Flow Meter Electronics
Armstrong Vortex Flow Meter electronics are available mounted directly to the flow body, or remotely mounted. The
electronics housing may be used indoors or outdoors, including wet environments. Available input power options are:
DC loop powered (2-wire), DC powered, or AC powered. Three analog output signals are available for your choice of
three of the five process variables: mass flow rate, volumetric flow rate, temperature, pressure or fluid density. A pulse
output signal for remote totalization and MODBUS or HART communications are also available.
Armstrong Vortex Flow Meters include a local 2 x 16 character LCD display housed within the enclosure. Local operation
and reconfiguration is accomplished using six push-buttons operated via finger touch. For hazardous locations, the six
buttons can be operated with the electronics enclosure sealed using a hand-held magnet, thereby not compromising the
integrity of the hazardous location certification.
The electronics include nonvolatile memory that stores all configuration information. The nonvolatile memory allows the
flow meter to function immediately upon power up, or after an interruption in power. All flow meters are calibrated and
configured for the customer’s flow application.

14 Designs, materials, weights and performance ratings are approximate and subject to change without notice. Visit armstronginternational.com for up-to-date information.
Chapter 2 – Installation Overview
The Armstrong Vortex Flow Meter installations are simple and straightforward. Both the Series AVF In-Line and Series
AVI Insertion type flow meter installations are covered in this chapter. After reviewing the installation requirements given
below, see page 16 for Series AVF installation instructions. See page 19 for Series AVI installation instructions. Wiring
instructions begin on page 32.
Warning!
Consult the flow meter nameplate for specific flow meter approvals before any hazardous location installation.
Flow Meter Installation Requirements
Before installing the flow meter, verify the installation site allows for these considerations:
1. Line pressure and temperature will not exceed the flow meter rating.
2. The location meets the required minimum number of pipe diameters upstream and downstream of the sensor head as
illustrated in Figure 2-1.
3. Safe and convenient access with adequate overhead clearance for maintenance purposes.
4. Verify that the cable entry into the instrument meets the specific standard required for hazardous area installa-tions.
The cable entry device shall be of a certified flameproof type, suitable for the conditions of use and correctly installed.
The degree of protection of at least IP66 to EN 60529 is only achieved if certified cable en-tries are used that are
suitable for the application and correctly installed. Unused apertures shall be closed with suitable blanking elements.
5. For remote installations, verify the supplied cable length is sufficient to connect the flow meter sensor to the re-mote
electronics.
Also, before installation check your flow system for anomalies such as:
• leaks
• valves or restrictions in the flow path that could create disturb-ances in the flow profile that might cause unexpected
flow rate indications

Designs, materials, weights and performance ratings are approximate and subject to change without notice. Visit armstronginternational.com for up-to-date information. 15
Installation Overview – continued
Unobstructed Flow Requirements
Select an installation site that will minimize possible distortion in the flow profile. Valves, elbows, control valves and
other piping compo-nents may cause flow disturbances. Check your specific piping con-dition against the examples
shown below. In order to achieve accurate and repeatable performance install the flow meter using the recom-mended
number of straight run pipe diameters upstream and down-stream of the sensor. Note: For liquid applications in vertical
pipes, avoid installing with flow in the downward direction because the pipe may not be full at all points. Choose to
install the meter with flow in the upward direc-tion if possible.
Minimum Required
Upstream Diameters
Minimum Required
Downstream Diameters
No Flow Conditioner With Flow Conditioner No Flow
Conditioner
With Flow
Conditioner
Example A A C C B B
1 10 D N/A N/A N/A 5 D 5 D
2 15 D 10 D 5 D 5 D 5 D 5 D
3 30 D 10 D 5 D 5 D 10 D 5 D
4 10 D 10 D 5 D 5 D 5 D 5 D
5 20 D 10 D 5 D 5 D 5 D 5 D
6 0 D 10 D 5 D 5 D 10 D 5 D
D = Internal diameter of channel. N/A = Not applicable
Figure 2-1. Recommended Pipe Length Requirements for Installation, Series AVF/AVI

16 Designs, materials, weights and performance ratings are approximate and subject to change without notice. Visit armstronginternational.com for up-to-date information.
Installation Overview – continued
Recommended Meter Locations
Liquid Horizontal
Liquid Vertical
Gas or Steam Horizontal
Gas or Steam Vertical

Designs, materials, weights and performance ratings are approximate and subject to change without notice. Visit armstronginternational.com for up-to-date information. 17
Installation Overview – continued
AVF In-Line Flow Meter Installation
Install the AVF In-Line Flow Meter between two conventional pipe flanges as shown in Figures 2-3 and 2-4.
The meter inside diameter is equal to the same size nominal pipe ID in schedule 80. For example, a 2” meter has an
ID of 1.939” (2” schedule 80). Do not install the meter in a pipe with an inside diameter smaller than the inside
diameter of the meter. For schedule 160 and higher pipe, a special meter is required. Consult the factory before
purchasing the meter.
AVF Meters require customer-supplied gaskets. When selecting gasket material make sure that it is compatible with the
process fluid and pressure rat-ings of the specific installation. Verify that the inside diameter of the gasket is larger than
the inside diameter of the flow meter and adja-cent piping. If the gasket material extends into the flow stream, it will
disturb the flow and cause inaccurate measurements.
Flange Bolt Specifications
Stud bolt lengths may be calculated using the following equation:
L = Meter face to face length + 2 (mounting flange thickness + flange raised face) + 2 (gasket thickness) + 4 (mounting
nut thickness)
Refer to the mounting flange specification to select the correct stud bolt diameter.
The required bolt load for sealing the gasket joint is affected by several application-dependent factors; therefore the
required torque for each application may be different. Refer to the ASME Pressure Vessel Code guidelines for bolt
tightening standards.
Figure 2-2. Flange Bolt Torquing Sequence

18 Designs, materials, weights and performance ratings are approximate and subject to change without notice. Visit armstronginternational.com for up-to-date information.
Installation Overview – continued
Wafer-Style Flow Meter Installation
Install the wafer-style meter between two conventional pipe flanges of the same nominal size as the flow meter. If the
process fluid is a liquid, make sure the meter is located where the pipe is always full. This may require locating the meter
at a low point in the piping system. Note: Vortex flow meters are not suitable for two-phase flows (i.e., liquid and gas
mixtures).
For horizontal pipelines having a process temperature above 300° F, mount the meter at a 45 or 90-degree angle to avoid
overheating the electronics enclosure. To adjust the viewing angle of the enclosure or display/keypad, see page 30 and
31.
Figure 2-3. Wafer-Style Flow Meter Installation
Caution!
When using toxic or corrosive gases, purge the line with inert gas for a minimum of four hours at full gas
flow before in-stalling the flow meter.
When installing the meter make sure the section marked with a flow ar-row is positioned upstream of the outlet, with the
arrow head pointing in the direction of flow. (The mark is on the wafer adjacent to the enclosure mounting neck.) This
ensures that the sensor head is positioned down-stream of the vortex shedder bar and is correctly aligned to the flow. In-
stalling the meter opposite this direction will result in completely inaccu-rate flow measurement. To install the meter:
1. Turn off the flow of process gas, liquid or steam. Verify that the line is not pressurized. Confirm that the installation site
meets the required minimum upstream and downstream pipe diameters.
2. Insert the studs for the bottom side of the meter body between the pipe flanges. Place the wafer-style meter body
between the flanges with the end stamped with a flow arrow on the upstream side, with the arrow head pointing in the
direction of flow. Center the meter body inside the diameter with respect to the inside diameter of the adjoining piping.
3. Position the gasket material between the mating surfaces. Make sure both gaskets are smooth and even with no
gasket material extending into the flow profile. Obstructions in the pipeline will disturb the flow and cause inaccurate
measurements.
4. Place the remaining studs between the pipe flanges. Tighten the nuts in the sequence shown in Figure 2-2. Check for
leaks after tightening the flange bolts.
Enclosure and display/keypad
are adjustable to suit most
viewing angles
Incorrect gasket position
– Do not allow any gasket
material to extend into the
flow profile
Shedder bar (bluff
body) is positioned
upstream of sensor

Designs, materials, weights and performance ratings are approximate and subject to change without notice. Visit armstronginternational.com for up-to-date information. 19
Installation Overview – continued
Flange-Style Flow Meter Installation
Install the flange-style meter between two conventional pipe flanges of the same nominal size as the flow meter. If the
process fluid is a liquid, make sure the meter is located where the pipe is always full. This may require locating the meter
at a low point in the piping sys-tem. Note: Vortex flow meters are not suitable for two-phase flows (i.e., liquid and gas
mixtures). For horizontal pipelines having a pro-cess temperature above 300° F, mount the meter at a 45 or 90-degree
angle to avoid overheating the electronics enclosure. To adjust the viewing angle of the enclosure or display/keypad, see
page 30 and 31.
Figure 2-4. Flange-Style Flow Meter Installation
Caution!
When using toxic or corrosive gases, purge the line with inert gas for a minimum of four hours at full gas
flow before installing the flow meter.
When installing the meter make sure the flange marked with a flow arrow is positioned upstream of the outlet flange,
with the arrow head pointing in the direction of flow. (The mark is on the flange adjacent to the enclo-sure mounting
neck.) This ensures that the sensor head is positioned downstream of the vortex shedder bar and is correctly aligned to
the flow. Installing the meter opposite this direction will result in completely inaccurate flow measurement. To install the
meter:
1. Turn off the flow of process gas, liquid or steam. Verify that the line is not pressurized. Confirm that the installation
site meets the required minimum upstream and downstream pipe diameters.
2. Seat the meter level and square on the mating connections with the flange stamped with a flow arrow on the upstream
side, with the arrow head pointing in the direction of flow. Position a gasket in place for each side. Make sure both
gaskets are smooth and even with no gasket material extending into the flow profile. Obstructions in the pipeline will
disturb the flow and cause inaccurate measurements.
3. Install bolts in both process connections. Tighten the nuts in the sequence shown in Figure 2-2. Check for leaks after
tightening the flange bolts.
Enclosure and display/keypad
are adjustable to suit most
viewing angles
Incorrect gasket position
– Do not allow any gasket
material to extend into the
flow profile
Shedder bar (bluff
body) is positioned
upstream of sensor

20 Designs, materials, weights and performance ratings are approximate and subject to change without notice. Visit armstronginternational.com for up-to-date information.
Installation Overview – continued
AVI Insertion Flow Meter Installation
Prepare the pipeline for installation using either a cold tap or hot tap method described on the following pages. Refer
to a standard code for all pipe tapping operations. The following tapping instructions are general in nature and intended
for guideline purposes only. Before in-stalling the meter, review the mounting position and isolation value requirements
given below.
Mounting Position
Allow clearance between the electronics enclosure top and any other obstruction when the meter is fully retracted.
Isolation Valve Selection
An isolation valve is available as an option with AVI meters. If you supply the isolation valve, it must meet the following
requirements:
1. A minimum valve bore diameter of 1.875 inches is required, and the valve’s
body size should be two inches. Normally, gate valves are used.
2. Verify that the valve’s body and flange rating are within the flow meter’s
maximum operating pressure and temperature.
3. Choose an isolation valve with at least two inches existing between the flange
face and the gate portion of the valve. This ensures that the flow meter’s sensor
head will not interfere with the operation of the isolation valve.