The FMG series of rotary gas metersare designed to meet the highest demands of reliable and accurate measurementof gas flow. The meters are MID approved and fully comply with EN12480 and OIMLR137. The compact exchangeable aluminium cartridge allows local repair andon-site cleaning. The robust design of the casing and the cartridge make themeter less sensitive to installation stresses caused by the connecting piping.A significant amount of misalignment of the connecting piping/flanges can betolerated by the meter without affecting the meter performance by jamming theimpellers.

The aluminium casing of the FMR (body and front plate) is designed for workingpressures up to 20 barg with a safety factor of 4. The square impellers and theimproved position of the main bearings and shafts, make the meter lesssensitive to overload and pressure shocks. The aluminum index and theprotection of the LF pulsers with the associated magnets, make the meter lesssensitive for manipulation by externally applied magnets or other externalforces. Tampering of meters with strong neodymium magnets is one of the majorconcerns of utility companies, as this kind of manipulation is very difficultto detect or prove. In order to be prepared for the “smart grid”, the index canalso be equipped with an intelligent encoder.

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

Principle

The FMG rotary gas meter is adisplacement type gas meter. The actual measurement is performed by two figure8-shaped impellers (rotors) rotating within a measurement chamber. During afull revolution of the rotors a fixed volume is displaced from the inlet to theoutlet of the meter. The number of revolutions represents the amount of volumepassed. The volume is displayed on a direct read counter type index. Severallow and high frequency pulsers can be used for flow computing or controlpurposes.  

Applications

The FMR series of rotary meters issuitable for custody transfer gas measurement of all non-corrosive gases suchas 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 useunder extreme conditions like higher temperatures and corrosive gases.