FMG - FMR Series - Rotary Meters

FMR Series - Rotary MetersThe FMG series of rotary gas meters are designed to meet the highest demands of reliable and accurate measurement of gas flow. The meters are MID approved and fully comply with EN12480 and OIML R137. The compact exchangeable aluminium cartridge allows local repair and on-site cleaning. The robust design of the casing and the cartridge make the meter less sensitive to installation stresses caused by the connecting piping. A significant amount of misalignment of the connecting piping/flanges can be tolerated by the meter without affecting the meter performance by jamming the impellers.

The aluminium casing of the FMR (body and front plate) is designed for working pressures up to 20 barg with a safety factor of 4. The square impellers and the improved position of the main bearings and shafts, make the meter less sensitive to overload and pressure shocks. The aluminum index and the protection of the LF pulsers with the associated magnets, make the meter less sensitive for manipulation by externally applied magnets or other external forces. Tampering of meters with strong neodymium magnets is one of the major concerns of utility companies, as this kind of manipulation is very difficult to detect or prove. In order to be prepared for the “smart grid”, the index can also be equipped with an intelligent encoder.

The unique proprietary oiling system, where the oil is distributed directly to the timing gears by means of a disc, eliminates oil loss at high rotor speeds and will lubricate the timing gears at very low loads. All plugs and oil sight glasses are in the front of the meter, allowing the meter to be installed in very compact installations.

Product DATASHEET - FMR Series Rotary Gas Meters


The FMG rotary gas meter is a displacement type gas meter. The actual measurement is performed by two figure 8-shaped impellers (rotors) rotating within a measurement chamber. During a full revolution of the rotors a fixed volume is displaced from the inlet to the outlet of the meter. The number of revolutions represents the amount of volume passed. The volume is displayed on a direct read counter type index. Several low and high frequency pulsers can be used for flow computing or control purposes.


The FMR series of rotary meters is suitable for custody transfer gas measurement of all non-corrosive gases such as natural gas, propane, butane, air, hydrogen, etc. Typical applications are:

> Gas distribution in low, medium or high pressure networks
> Industrial applications
> Master meters for test benches

Special constructions can be supplied for use under extreme conditions like higher temperatures and corrosive gases.

Main Features

- Flow range 0.2 – 1000 m3/h
- Diameters DN25 – DN200 (1” – 8”)
- Pressure rates PN 10 – 100, ANSI 150 – 600

- Compliant with EN12480:2002
- Compliant with EN12480:2015
- Compliant with OIML R137 1&2 (2014)
- Compliant with MID 2014/32/EU

- MID temperature range -40 to +70ºC
- Large rangeability > 1:160
- Cartridge design
- Robust construction

- Multi position
- Square impeller technique
- Compact installation

- Easy local repair
- On-site cleaning
- Tamper proof exchangeable index
- Seals according EN 549 (seals for gas appliances and gas equipment)

Technical Specification

Metrological approvals: Compliant with EN12480:2002
Compliant with EN12480:2015
Compliant with OIML R137 1&2 (2014)
Compliant with MID 2014/32/EU

ATEX approvals: Sensors compliant with Ex ia IIC T4... T6 Gb (-40ºC ≤ Ta +70ºC)
Encoder compliant with Ex ib IIB T3... T6 Gb (-25ºC ≤ Ta +55ºC)

Flow rates: 0.2 m3/h up to 1000 m3/h

Nominal diameters: From DN25 to DN200 mm (1” to 8”).

Mounting position: Horizontally or vertically

Body: Compliant to Pressure Equipment Directive 2014/68/EU

Temperature Range: ATEX: -25°C to +70°C
MID: -25°C to +70°C (lower temperatures on request)
PED: -20°C to +70°C (lower temperatures on request)


Body: Aluminium
Impellers: Aluminium
Cartridge: Aluminium

Timing gears: Carbon steel
Bearings: Carbon steel / stainless steel
Shafts: Stainless steel

Gears: Delrin
Index frame: Aluminium
Index cover: PolycarbonateECI

Typical metrological characteristics

Accuracy Qt to Qmax: ± 1% or better
Accuracy Qmin to QT: ± 2% or better
Repeatability: better than 0.1% 

FMG Gas Meters FMR series are NMIM certified by SIRIM and also certified by NMI International.

FMG Gas Meters are NMIM certified by SIRIM

NMI International