Rotary Gas Flow Meter (pulsation free)

Turbine meters have a limited range and must preferably be calibrated close to the operating conditions (high pressure natural gas). This limitation and the higher costs due to the calibration, make the larger rotary meters more popular as replacement for the turbine meter.To overcome the drawback of conventional rotary meters (pulsations and resonance), pulsation free rotary meters have been developed. These pulsation free rotary meters, using two phase shifted pairs of impellers, fully eliminate the pulsations by countering the characteristic sine wave and its resultant resonance. As a result the pulsation free rotary meters series DUAL are extremely quiet and accurate.

Another advantage is the use of relatively short impellers. Shorter
impellers will not deform easily and as such provide reliable long
term performance. The weak point of pulsation free meters can
be the connection of the two impeller pairs as this mechanical
coupling is very sensitive to load differences between the two sets
of impellers. The FMG DUAL meter uses a significantly stronger
spline and spline shaft to connect the two pairs of impellers.