DESIGN AND FUNCTION

The gas flow through the rotary gas meter measurement chamber makes the two “8”-shaped rotors to turn. The volume of gas closed between the measuring chamber walls and rotors is transported four times in one full cycle from the meter inlet to the outlet. The timing gears set the rotors at the angle of 90° one to the other. The gear train, and the incorporated gas tight and hermetic magnetic coupling, transfers the rotor rotation to the index unit, which is separated in that way from the pressure tight housing. The actual volume of gas is indicated on the mechanical counter. The measurement cartridge, as a separate unit, is fixed in the pressure resistant housing by means of elastomere gaskets. Thanks to this, the possible stresses, e.g. arising from improperly aligned piping, have no influence on measurement results of the CGR Rotary Gas Meter. Moreover, the measuring cartridge elements are made of materials with carefully selected values of thermal expansion  coefficients. This minimizes temperature stresses that could cause the rotor seizures. All above factors, together with the highest precision machining of parts allow to reduce small but necessary clearances between the moving rotors and the measurement chamber walls, what  reduces gas leakages to minimum and results in very high accuracy and wide measuring ranges of our CGR Rotary Gas Meters. The CGR Rotary Gas Meter consists of the following main assemblies:

All parts subject to servicing or maintenance, like mechanical counter, LF (HF) sockets, oil filler and drain plugs, oil level sight-glass, are located on the front side of the meter. Thanks to this, it is not necessary to access the back side of the CGR meter and then it could be located very close to a wall or other construction element what reduces the installation deep.