FMT-Lx Turbine Gas Meter Flow Meter Group


FMT-Lx Turbine Gas Meter is a robust meter, designed to perform at the highest level of accuracy. The meters comply with all international standards and are approved for custody transfer. The actual flow sensor, an exchangeable cartridge, has a built-in multi-stage flow conditioner enabling the meter to be installed without any straight in- and outlet sections. All were tested and proved according to the perturbation test as per international standards.

The cartridge can be pre-calibrated, under both low and high-pressure conditions, then exchanged on-site. The cartridge is supported in O-rings and isolated from the body, hence unaffected by any influences of the housing. The short-length cartridge enables the use of larger-sized cartridges than the size of the meter body.

The approved maximum capacities of these kinds of meters are extremely high and similar to the capacities of ultrasonic meters. To reduce transportation costs, optimize corrosion protection, and improve safety in handling, the FMT-Lx series of turbine meters up to 6’’ (DN150) are also available with low-weight aluminum meter bodies.

FMT-Lx Turbine Gas Meter Principle

The operation of the FMT series of turbine meters is based on the measurement of the velocity of the gas. The flowing gas is accelerated and conditioned by the integrated multi-stage flow conditioner. The multi-stage flow conditioner prepares the gas flow profile by removing undesirable swirl and asymmetry before the gas flows over the freely rotating turbine wheel.

The dynamic forces of the flowing gas cause the rotor to rotate. The turbine wheel is mounted on the main shaft, with high-precision, low-friction ball bearings. The turbine wheel has helical blades that have a known angle relative to the gas flow. The gas flow drives the turbine wheel at an angular velocity, which is proportional to the gas velocity. Using a gearing mechanism, the rotating turbine wheel drives the mechanical counter.


  • Body (Standard): Low-weight aluminum/steel Bearings: Stainless steel
  • Body (Optional): Low-temperature steel Shafts: Stainless steel
  • Cartridge: Aluminum Gears: POM
  • Straightening vane: Aluminum Index frame: Aluminum
  • Turbine wheel: Aluminum Index frame: Polycarbonate ECI
  • Bearing block: Stainless steel/aluminum standard FMT-Lx turbine meter is suitable for custody transfer gas measurement of all non-corrosive gases such as natural gas, propane, butane, air, nitrogen, hydrogen, etc. for low and high operating pressures.
  • Special constructions can be supplied for use under extreme conditions like high temperatures or corrosive gases.  The FMT-Lx can be modified to perform as a master meter or transfer master meter.


  • Flow range 3- 40.000 m3 /h
  • Diameters DN50 – DN600 (2” – 24”)
  • Pressure rates PN 10 – 100, ANSI 150 – 600
  • Compliant with EN12261:2002
  • Compliant with EN12261:A1-2006
  • Compliant with OIML R137 1&2 (2014)
  • Compliant with MID 2014/32/EU
  • MID temperature range -25 to +70ºC
  • Length 3x DN
  • Removable meter cartridge
  • No straight inlet/outlet sections required
  • Oil flushing and lubrication system
  • Multipurpose exchangeable index
  • Tamper-proof IP67 sealed index
  • Special meters on request
  • Seals according to EN 549 (seals for gas appliances and gas equipment)


The FMT-Lx fulfills all the requirements of the European and International directives. In particular those of the OIML, ISO, and EN. With the special integrated flow straightener, the FMT-Lx eliminates the effect of severe perturbations on gas measurement. Straight inlet and outlet piping can be 0 X DN. This permits the design of very compact installations without losing accuracy.

Heavy duty bearings

Since gas pressure causes the main force on the bearings the FMT-Lx series incorporates bearings dedicated to the working pressure. FMT-Lx turbine meters that have a low working pressure are equipped with lighter bearings then the meters which are used at higher working pressures. This way the best measuring ranges and lifetimes can be guaranteed

FMT-Lx Turbine Gas Meter Specification:

Metrological approvals: Compliant with EN12261:2002
Compliant with EN12261: A1-2006
Compliant with OIML R137 1&2 (2014)
Compliant with MID 2014/32/EU
ATEX approvals: Sensors were compliant with Ex ia IIC T4… T6 Gb (-40ºC ≤ Ta +70ºC)
Encoder is compliant with Ex ib IIB T3… T6 Gb (-25ºC ≤ Ta +55ºC)
Flow rates:  3 m3/h up to 40.000 m3/h
Nominal diameters:  From DN50 to DN600 mm (2” to 24”).
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)

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