Rotary Meters Series FMR

General Description.

The FMG rotary gas meter is a displacement type gas meter. The actual measurement is performedby two 8-shaped impellers in combination with a measurement chamber. During a full revolution ofthe impellers a fixed volume is displaced from the inlet to the outlet of the meter. The number ofrevolutions represents the amount of volume passed. The volume is displayed on a direct readcounter type index. Several low and high frequency pulsers can be used for flow computing orcontrol purposes.The FMG series of rotary gas meters are designed to meet the highest demands of reliable andaccurate measurement of gas flow. The meters fully comply with the EN12480 and OIML R137directives. The compact exchangeable aluminum cartridge allows local repair and on-site cleaning.The robust design of the casing and the cartridge makes the meter less sensitive to installationstresses caused by the connecting piping. A significant amount of misalignment of the connectingpiping/flanges can be tolerated by the meter without affecting the meter performance or locking theimpellers.

The aluminum casing (body and cover) is designed for working pressures up to 21 bar (300 psi)with a safety factor of 5. The square impellers and the improved position of the main bearings andshafts, makes the meter less sensitive to overload and pressure shocks.

The aluminum index and the protection of the LF pulsers with the associated magnets, makes themeter insensitive to manipulation by externally applied magnets or other external forces.Tampering of meters with strong neodymium magnets is one of the major concerns of utilitycompanies, as this kind of manipulation is very difficult to detect/prove. In order to be prepared forthe “smart grid”, the index can be equipped with an intelligent encoder.

The unique proprietary oiling system, where the oil is distributed directly to the timing gears bymeans of a disc, eliminates oil loss at high impeller speed and will lubricate the timing gears at verylow loads. All plugs and oil sight glasses are in the front of the meter, allowing the meter to beinstalled in very compact installations.

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Cartridge Design

All FMR meters consist of an aluminum cartridge inserted in ameter body. The cartridge can be removed and inserted withthe body remaining installed This allows local repairs such asreplacement of the main bearings and on-site cleaning to becarried out without removing the meter body. Particularowners of older networks, suffering from dirt and/orcondensate, will benefit from the ability to remove thecartridge. FMG has a cartridge exchange program to replaceolder cartridge by newly calibrated ones.

Highlights

Cartridge DesignRobust Construction

Low Sensitivity to Installation StressMulti Position

Square Impeller TechniqueCompact Installation

Easy Local RepairOn-Site Cleaning

Integrated Thermo wellsTamper Proof IndexClass 1 or Class 1.5

1:160 Range500mT Magnetic Field Resistant

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Square Impeller Technique

The use of square impellers not only makes the meter veryrobust and short, but also improves the accuracy andrangeability. The unregistered leakage causing an error atminimum capacity, thus limiting the rangeability, issignificantly smaller for square impellers (shorter outline)compared to the traditional long impellers.

Robust Construction

In the new cartridge design, the impellers, timing gearsand bearings are fixed and positioned by a synchroplate.Since this synchroplate is machined in one operation, thetolerances can be controlled and maintained at a very highlevel. As a consequence, the clearance between theimpellers and the meter body is equally divided and assuch maximized, making the meters less sensitive to dirtand debris.

The short impeller and high strength shaft connecting thetiming gear to the impeller overcomes flexing or bendingof the impellers, hence the meters are less sensitive toflow and pressure shocks. Severe intermittent on/offapplications are typically handled without damage.Temporarily overloading the meter up to 50% of themaximum capacity will not cause any degradation of themetrological quality.

Low maintenance / Easy repair

The use of a cartridge (pre-calibrated) and the accessibilityof the front and rear bearings (without the need forremoving the timing gears), makes the FMG series ofrotary meter unique in terms of repair. Every repair shopcan repair or re-condition the meters without special skillsand tools. When regulation permits, a new, calibratedcartridge can be installed.

Tamper Proof

All plugs, sensors and oil sight glasses can be sealed (wire)and as such the meter is not sensitive to tampering. If, forexample, the oil compartment is accessible, themetrological performance can be changed (increasing ordecreasing mechanical friction) by changing oil properties.

Special shielding of the LF pulsers protects the meter indexprotected from externally applied magnetic fields up to 500mT.

The double wall index can not be opened or intrudedwithout visual damages. An additional glass shieldmounted under the polycarbonate window will break incase excessive forces are applied. The index can be fixedto the meter body by sealed (customer seal) bolts.

In addition to the mechanical precautions, the index canbe equipped with an intelligent encoder, recording timestamping of all attempts of unauthorized access ormanipulation, such as magnetic interference, reverseflows, etc.

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mMultifunctional Aluminum Index

The extremely strong double walled, aluminum, index is designedto withstand any external interference. To protect against largeforces applied to the index window, an additional glass window ismounted beneath the polycarbonate window. This glass windowwill break in case excessive force is applied to the index.

Four slots in the outer extrusion can be used for various add-onssuch as multiple connectors, additional outgoing shafts, markingplates with bar codes for example, etc. The use of slots makesthe index multifunctional and as such “prepared for the future”.

Options available are: multiple LF pulsers, multiple connectors,encoders, magnet field protection and a reverse flow lock(preventing meters from registering backwards in case oftampering). The index can be rotated over 3500 for flowdirections left–right and bottom-top. Optionally, the index can beequipped with a double counter allowing the change of flowdirection on-site. Various techniques of sealing the meter and theindex are available.

Options Index / Instrument Drive

The index or instrument drive can be equipped with severaloptions making the meter prepared for the future:

Magnetic Field Protection (up to 500 mTesla); The LF pulsersand its driving magnet can be shielded to overcome tamperingwith an externally applied magnetic field. Magnetic fields up to500 mT will not have an effect on the pulse counting.

Reverse Flow Lock; In order to avoid tampering by reverseflow, the index or instrument drive can be equipped with aReverse Flow Lock.

Intelligent Index/Encoder: The index can be equipped with anintelligent encoder. The encoder sends out the total volume withan interval of 400 msec. The encoder uses a standard NAMURserial data format, and can be modified to special applications onrequest. The encoder is powered by one AA cell batteryguaranteed for 12 years of operation. On request two AA cellscan be installed for a guaranteed life time of 20 years. Theencoder is equipped with a special Hall sensor to detect andregister interferences from external magnets. Severalprogrammable inputs/outputs are available for advanced – antifraud – functions.

Instrument Drive / Side Reading

The instrument drive can be used to mount auxiliary equipmentlike chart recorders or mechanically driven volume correctors.The rotation of the outgoing shaft is equal to one m3 or CF or(sub) multiple thereof. A single or double counter can be addedto the instrument drive. The instrument drive can be rotated over900, hence allowing both horizontal and vertical installation.The instrument drive can be equipped with low frequency pulsers,an encoder as well as a reverse flow lock preventing meters fromregistering backwards in case of tampering. On request the indexcan be supplied as side reading (without instrument drive)allowing the meter to be installed in an extremely high or lowposition. The rotating direction of the output shaft can bechanged on site

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Superior Metrological Performance

Starting with the G40, all meters are approved according toboth EN12480 and OIML R137/1 for rangeabilities up to 1:160and as such can, on request, be designated as Class 1.5meters. In situations where the installation- or gas conditionsare severe, the risk of rejection is elevated when recalibrationis done against in-service tolerances. The designation of class1.5 (instead of 1.0) , while still maintaining the class 1.0accuracy limits, could be of interest since the in-servicetolerances of a class 1.5 meter are significantly larger than theclass 1.0 tolerances.

Designed For Logistical Optimization

FMG rotary meters have exchangeable cartridges and as suchcan be maintained and repaired locally. In order to calibratethe cartridge or meter locally in accordance with the applicablemetrological laws and directives, the meters are prepared fortesting with a high frequency optical sensor. By using the HFsignal, the test time becomes significantly shorter and theuncertainty of the calibration is improved. Due to this highfrequency feature, a test at the lowest flow rate can beperformed within the maximum allowable test time (EN12480). Since the reference disc acting on the sensor is directlyconnected to the main shaft of the impeller, the repeatability ofthe resulting high frequency pulses is extremely good, hencethe high frequency signal becomes very suitable for timemeasurement (the most accurate and fastest way to calibratemeters).

FMG rotary meters do not have sight glasses, connections orplugs in the rear and as such have a short installation depth.Actually, with the exception of the G160 and G400, theinstallation depth is comparable with the depth of the adjacentflanges and as such the meter will always fit in the installation.Due to the extremely rigid construction additional flexibleconnections to compensate for installation stress are notneeded.

FMG rotary meters do have multiple sight glasses and oil plugs on the front and as such themeter becomes suitable for all installation positions. Whether the direction is left-right, right-leftor top-down, the meter is suitable and accurate.

The very large rangeabilities, more than 1:160, can also be used to limit the number of differentmeter types. It is possible to consider having only one type per flange size on stock. For instancea 2” G65 (range 1:160) can easily been used as an G40 (range 1:100). The same applies for the3” G160 and G100.

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Installation

Installation of FMG rotary meters can be horizontal or vertical. Since the meter is designed for multiposition, consideration need only be given to the arrow on the front cover showing the flow direction.After the meter is installed, the index can be rotated to the correct position. The index can be rotatedover 3500. FMG rotary meters can be metrological sealed by various systems from total flexibility tohighly tamper proof.

Low Frequency Pulsers

FMG rotary meters can be equipped with several low frequency pulsers (single or double reed switch,tamper detection, etc.) and connectors (Binder male and female). On request, multiple connectorsare available (for utility and user). The Low frequency pulsers and its associated magnets can beprotected against externally applied Magnetic Fields up to 500mT.

Maintenance

FMG rotary gas meters have a rotating disc for distributing the oil directly to the timing gears. Themechanism is designed to prevent oil loss at high loads or from pressure variations and maintainssufficient oiling at low flows. Since the oil system operates between 40% and 120% of the maximumflow, sizing of the installation is no longer critical. The oil supplied with the meter is suitable for 10years of operation under normal conditions.

Cleaning / Repairing

After removing the front cover of the meter, the entire cartridge can removed for cleaning. Duringthis cleaning process, the meter body can remain in line. For cleaning purposes the seals of the frontcover have to be removed. The construction of the FMG rotary gas meters allows local repair orreplacement of all the main bearings without special tools. In case the main bearings are replaced,the critical timing of the impellers is secured. It is recommended that replacement of the mainbearings (mounted in the synchroplate) be done by a skilled technician in a clean environment. Therear bearings can be replaced with the meter body in situ. In case a meter is locked by dirt, thecartridge can be removed for cleaning.

Applications

- Gas distribution in low / medium / high pressure networks- Industrial applications- Master meters for test benches

Integrated Double Thermowells

FMG rotary meters can be equipped(optional) with two integrated thermo wells.Having two thermowells, the verification ofElectronic Volume Conversion Devices (whenbuilt into the meter) can be done on site andon line without interruption of the operation.

By comparing the reading of EVCDtemperature sensor with a calibratedtemperature sensor or one of known accuracyplaced in the second thermowell, the EVCDcan be verified.

Since the thermowells are isolated with O-rings and make minimal contact with themeter body, the temperature measurementin the well is almost identical to the actualconditions of the gas flow stream. As a result,the uncertainty element of the correctedvolume is very small.

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136,54650150> 260G400

136,54650100241G400

842,5400100241G250

52,51,6250100241G160

52,51,625080241G160

52,51,625080/100171G160

3,21,6116080171G100

210,6510050171G65

1,30,650,46550171G40

0,80,44050171G25

0,52550171G16

Qmin (m3/h)

50100160

Measuring Range (MID)

Qmax (m3/h)Size (mm)Length(mm)Type

Typical error curve

-1

-0,5

0

0,5

1

0 10 20 30 40 50 60 70 80 90 100

% Qmax

Error

(%

)

Measuring Ranges

Approvals

The FMG rotary meters are approved /accredited according:

- 2004/22/EC (MID)- 97/23/EC (PED)- 94/9/EG (ATEX)- 2004/108/EG (EMC)

Metrology

The accuracy is in accordance with MID (EN12480, OIML R137-1/2):

Atmospheric Air: 0,2 Qmax – 1,0 Qmax : +/- 1%Qmin – 0,2 Qmax : +/- 2%

Repeatability: 0,2 Qmax – Qmax : +/- 0,10%Range: Up to 1 : 160 (larger ranges on request)Accuracy Class: 1 or 1,5The pressure loss: in accordance with the EN12480 and OIML R137-1

All metrological approvals are performed by the Dutch NMi. On request, a copy of the official NMidocuments can be provided.

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Steel (optional Stainless)Plugs

Poly Carbonate, UVstabilized / GlassIndex glass

Aluminum anodizedIndex

POMGears

Stainless steelBearings

Steel / Stainless steelShafts

Aluminum, hard coatedSynchro plate

Aluminum, hard coatedImpellers

Aluminum, hard coatedMeter bodyMaterials

Multiple AA cells on request

Life time 12 years with one AA cell

Gray Code EncoderIntelligent Index

Multiple connectors on request

Binder male or femaleConnectors

Normally Closed Switch

Double Reed SwitchElectrical Outputs

Reproducibility < 0,15%

Rangeability 1:160

+/-3% for Qmin - Qt

+/-1,5% for Qt-QmaxAccuracy Class 1,5

Reproducibility < 0,1%

Rangeability up to 1:160

+/-2% for Qmin - Qt

+/-1% for Qt-QmaxAccuracy Class 1,0

1/4" NPT / 6 mmTemperature Tapping Tm

1/4" NPTPressure Tapping P

1/4" NPTPressure Tapping Pm (Pr)

e II 2 G / Ex ia IIC T4…T6ATEX Approval

EN12480, OIML R137-1/2Applicable Standards

MID by NmiMetrological Approvals

PEDSafety Approvals

Natural gas, Town gas, Inert gasesMedia

21 barg (up to 30 bar on request)Max. Operating Pressure

-25 to +55 C (-40 to +70 C)Ambient Temperature

-25 to +55 C (-40 to +70 C)Gas Temperature

500 mT for IndexMagnetic Field Resistance

1,0 / 1,5Accuracy Class

IP54, IP67 on requestProtection Class Index

M2 / E1Environment Class

Technical Data

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Flow Meter Group, Meniststraat 5c, 7091 ZZ Dinxperlo, The Netherlands

Your Contact

Subject to changes without prior notice All rights reserved FMR EN002 rev10

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595

481

411

473

397

346

346

346

346

A1(mm)

300

243

208

265

227

196

196

196

196

C(mm)

3772185186528824150G400

3201604036528824138G250

2851263346528824132G160

3431303966520217118,5G160

305923206520217114G100

273722686520217112G65

273722686520217112G40

273722686520217112G25

273722686520217112G16

C1(mm)

B(mm)

A(mm)

F(mm)

H(mm)

L(mm)

Weight(kg)

c1

A1

Dimensions