The diaphragm gas meter, also known as the membrane gas meter, is a volumetric flowmeter that uses the periodic expansion and contraction of a flexible diaphragm (membrane) to separate and push gas, and measures the cumulative volume of gas by counting the number of cycles.

1. High reliability origin: The bladder is the only dynamic sealing component. Its flexible deformation replaces the rigid friction seal of the piston, resulting in minimal wear and an extremely long service life (up to hundreds of thousands of cycles). This is the core reason for its reliable operation for over 10 years.
2. Key to wide range ratio: The bladder is highly sensitive to extremely small pressure changes (a few pascals) and can respond to very low flow rates (such as a candle flame). At the same time, its deformation stroke is large enough to handle high flow rates. This gives it an ultra-wide range ratio of 160:1.
3. Source of pressure loss: Overcoming the material elasticity and inertia of the bladder during deformation is the main part of the internal pressure loss of the instrument.
4. Decisive factor for accuracy: The long-term stability of the effective deformation volume of the bladder directly determines the measurement accuracy. Material aging, plastic deformation, and contamination adhesion can all change the volume, requiring regular verification.
5. Absolute installation requirement: The bladder will sag under the influence of gravity. It must be installed strictly horizontally to ensure symmetrical force on both bladders and equal deformation volumes. Inclined installation will lead to significant errors.

1. Household gas metering: connected to stoves, gas water heaters, and wall-hung boilers. Common specifications are G1.6, G2.5, and G4.
2. Commercial gas metering: small restaurants, canteens, bakeries. Common specifications are G6, G10, and G16.
3. Distributed energy metering: total meters for gas-heated buildings in residential areas, gas metering for small gas boilers.

The diaphragm gas meter (membrane gas meter) is one of the ultimate examples of "simple, reliable and ingenious" engineering design. It perfectly combines the characteristics of flexible materials with precise linkage mechanisms, and uses a seemingly "low-tech" diaphragm to solve the worldwide problem of civil gas metering with an ultra-wide range, extremely low flow rate and long-term maintenance-free.