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Gas recovery technology for replacing gas meters

When replacing a gas meter for a customer whose meter is installed in an underground location or a high-rise condominium, Tokyo Gas must access the indoor gas appliance in the presence of the customer, and replace the air inside the new gas meter with city gas before the meter can be used. To further improve convenience and safety for our customers, we have developed a “gas adsorption and recovery system method” that enables replacement of gas meters by adsorption and recovery of the gas from the outside of the building.


The replacement of gas meters is a legal requirement under the Measurement Act, and gas meters are accordingly replaced on a regular basis. New meters contain air that needs to be replaced with city gas after installation of the meter and before usage of city gas. The process of replacing the air in the new gas meter with city gas requires access to a customer’s gas appliance. To improve customer satisfaction, a method is required that supports meter replacement work from the outside of the building.

Development overview

We developed a method that recovers air inside a gas meter from the outside of the building using a gas adsorption and recovery container that is filled with activated carbon, and replaces the air with city gas. The container can collect up to ten times of its volume in air and city gas due to the gas adsorption effect of the activated carbon.
By first reducing pressure in the adsorption and recovery container and bringing the device on-site (e.g., to an underground location or high-rise condominium), city gas released during the gas meter replacement work can be safely adsorbed and recovered on-site. This allows us to safely conduct gas meter replacements even when customers are absent.
Town gas absorption and recovery container Pump used to refresh thecontainer
after recovering absorbed gas
Image of meter replacement work in a basement Image of meter replacement work in a high-rise condominium


  1. Facilitates easy adsorption and recovery of city gas on-site using only valve operation (no power source required).
  2. Able to repeatedly refresh (through vacuum drawing) the adsorption container after usage.
  3. Able to replace gas meters in underground locations or high-rise condominiums without diffusing the gas into the atmosphere, even when customers are absent.


Going forward, the need for technology that facilitates on-site recovery of gas is projected to further expand in tandem with an increase in the number of underground shopping malls in urban areas and construction of new high-rise condominium projects. As this will result in an increase in the frequency of gas adsorption and recovery work, we aim to continue our development of technologies such as improvement about the workability of our adsorption and recovery container.

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