COX Exact Dual Rotor User Manual
TRB-UM-00478-EN-01 (September 2018)
User Manual
Turbine Flow Meters
Exact Dual Rotor
CONTENTS
Scope of This Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Unpacking and Inspection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Safety Considerations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Terminology and Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Traditional Operating Principle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Dual Rotor Advantages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Performance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Placement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Filtration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Notes on the Swirl Eect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Valves and Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Bearing Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Visual Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Recommended Spare and Replacement Parts . . . . . . . . . . . . . . . . . . . 11
Troubleshooting . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . 12
Mechanical Issues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Electrical Issues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Flow Range Specications .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . .. . 13
Sizing and Range. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Dual Frequency Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
AN End Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
NPT End Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Flange End Connection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Hose Barb End Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Part Numbering Construction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Turbine Flow Meters, Exact Dual Rotor
September 2018TRB-UM-00478-EN-01Page ii
Scope of This Manual
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SCOPE OF THIS MANUAL
This manual is intended as an installation and operation guide for the Cox Exact Dual Rotor
turbine flow meter. Please consult the factory or our website for any questions or concerns
regarding any of the equipment or installation. The electronic version of this manual is
available on our website at www.badgermeter.com.
IMPORTANT
Read this manual carefully before attempting operation. Keep the manual in an
accessible location for future reference.
Unpacking and Inspection
Upon opening the shipping container, visually inspect the product and applicable
accessories for any physical damage such as scratches, loose or broken parts, or any other
sign of damage that might have occurred during shipment.
OTE:N If damage is found, request an inspection by the carrier’s agent within 48 hours of
delivery and file a claim with the carrier. A claim for equipment damage in transit
is the sole responsibility of the purchaser.
Inspect all packing material carefully to prevent the loss of meter parts or auxiliary
components, which may have been packed with the shipment. Refer to the packing list/
invoice for a detailed list of items included in the shipment.
SAFETY CONSIDERATIONS
Terminology and Symbols
Indicates a hazardous situation, which, if not avoided, is estimated to be
capable of causing death or serious personal injury.
WARNING
Indicates a hazardous situation, which, if not avoided, could result in
severe personal injury or death.
Indicates a hazardous situation, which, if not avoided, is estimated to be
capable of causing minor or moderate personal injury or damage
to property.
Description
September 2018TRB-UM-00478-EN-01Page 4
DESCRIPTION
The Exact Dual Rotor turbine flow meter uses a unique rotor design that reduces swirl
effects. These flow meters are designed and manufactured to the highest quality standards
to provide the best possible performance for flow measurement requirements.
Traditional Operating Principle
A turbine flow meter, in its base form, measures fluid velocity. As a fluid passes through the
meter, the velocity of the fluid presses rotational energy on the internal rotor assembly. The
rotor blades generate pulses proportional to flow as they pass through a radio frequency
field created by a pickup. Each pulse is transmitted to the meter electronics, where it
amplifies the pulse output and provides a volumetric flow rate.
Dual Rotor Advantages
The dual rotor design eliminates many of the problems associated with traditional single
rotor designs. The hydraulic coupling of the two rotors reduces the fall-off of the output
frequency at low flow rates, extending the usable range, or turndown ratio. Additionally,
swirl at the meter inlet, which causes a significant inaccuracy in a single rotor meter, is
largely canceled by summing the counter-rotating rotor signals.
Performance
The performance of any turbine flow meter is affected by three forces, which can cause the
output signal to become non-linear: bearing friction, viscous drag, and magnetic drag (from
magnetic type pickups). Bearing friction is minimized by using exceptionally high quality
ball bearings. Viscous drag, which is a function of the metered fluid, cannot be eliminated.
Magnetic drag is eliminated by the use of modulated carrier (RF) pickup coils.
Bearing friction and viscous drag are accounted for by calibrating the flow meter on a
primary standard positive displacement liquid flow meter calibrator.
MATERIALS
Body 316 stainless steel
Shafts 316 stainless steel
Rotors 17-4 PH stainless steel
Bearing Ceramic ball, with hybrid corrosion resistant raceways
Nuts ASTM A286
Spacers 303 stainless steel
Supports 303 stainless steel
Transitions 302 stainless steel
Construction
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CONSTRUCTION
10
3
1
12
11
13
13
12
4
7
6
9
5
7
4
2
8
Figure 1: Cox Exact Meter sectional view
Item Description Item Description
1 Shaft 8 Lock Nut
2 Upstream Support 9 Spacer
3 Downstream Support 10 Housing
4 Transition 11 Hub
5 Upstream Rotor 12 End Connections
6 Downstream Rotor 13 Embedded Pickup Coil
7 Bearings
Table 1: Cox Exact Meter sectional view data
The Cox Exact design uses a tie-bolt concept, where the rotors are suspended in the
housing on a common stem. The stem is threaded into the downstream support, except
for the 1/4 in. (84) and 3/8 in. (86) sizes where it is captured on both ends with a nut. Stem
nuts are held in place with high temperature locking compound. The Cox Exact turbine
flow meter does not contain snap rings or retaining rings that can be dislodged by shock
or vibration.
Cox Exact flow meters use an embedded, radio frequency pickup coil that is not field-
replaceable. The low profile design of these meters requires a specialized potted pickup
that must be returned to Badger Meter, if it requires service or replacement. This type of
embedded pickup is vibration resistant and allows for a compact, overall meter size.
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