Water Supply Mechanism

Since April 2005, Water Works Bureau has expanded the number of booster pumps installed in water supply pipes to 75 mm in diameter to deliver safe and delicious water to customers in condominiums and office buildings. As a result, most apartments and office buildings in the city can provide direct water supply from the water pipe to the customer's faucet without going through the water receiving tank.

As a result of investigating a new method of direct pressure booster type water supply system (hereinafter referred to as "directly connected multi-stage booster water supply"), Water Works Bureau has been accepting applications for water supply equipment construction using this method from May 2011 to expand direct water supply to high-rise buildings.
The direct pressure booster type water supply, which supplies water directly from the water pipe to the faucet with a booster pump, can be expected to provide safer and more delicious water, promote energy conservation, and reduce construction costs and maintenance management fee compared to the receiving tank type water supply. With the introduction of the direct connection multi-stage booster water supply, the height limit that had been up to the middle and high-rise buildings is now possible.

1. Supply of safer and more delicious water

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   Water is supplied directly to the faucet without going through the water receiving tank, so safer and more delicious water can be supplied.

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2. Reduction of construction costs and space saving

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   The construction cost related to the water supply equipment can be reduced compared to the receiving tank type water supply, and the water receiving tank space is no longer required, so effective use of the space can be achieved.

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3. Reduction of management fee

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   Since there is no water receiving tank, there is no need for management fee.

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4. Reduction of electricity costs and promotion of energy conservation

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   Effective use of the water pressure in the distribution pipe, it is possible to supply water with less power than the pressurized water supply pump used in the receiving tank type water supply, which can reduce power costs and save energy.

• Construction costs for installing the booster pump and connecting to the maintenance management fee and water pipes will be borne by the installer.
• In order to maintain the function of the booster water supply equipment properly, regular inspections are required once a year by a manufacturer with specialized technology.

Japan Water Works Association (JWWA B130) standard products or products equal to or higher than that of the standard products

Japan Water Works Association (JWWA B134) standard products or products equal to or higher than that of the standard products

The upper limit of the direct connection direct pressure water supply was up to the 4th floor, but from May 2011, it was set to a level where water can be supplied with a water supply water pressure of 0.25 Mpa of the branching water pipe.

If the branching water pipe corresponds to an area with a water supply pressure of 0.25 Mpa or more, the water pressure (less than 0.25 Mpa), the water pressure answered by Water Works Bureau (less than 0.25 Mpa).

If you wish to have a direct connection direct pressure water supply of 3 stories or more, submit a water pressure survey request form to the Water Works Bureau Water Supply Construction Reception Center in advance, and whether the planned water supply branch will correspond to an area with a water supply pressure of 0.25 Mpa or more. Investigation is required.

Once tap water is put into an aquarium, this water is supplied directly by a pump, or sent to an elevated water tank installed on the roof, etc., and supplied.
In addition, the water receiving tank method has a stock function to secure water in the event of a disaster such as a water outage or an earthquake due to an accident in a water supply facility.
In addition, the receiving tank is to have the installer or manager perform maintenance such as inspection, cleaning at least once a year.
※Please consult with each ward Health and Welfare Center Environmental Sanitation Section for maintenance such as inspection and cleaning of the receiving tank.
-For customers using the receiving tank-Recommendation of switching to direct water supply (PDF: 1,714KB)

For details on the water supply method, please contact the following contact information.
Water supply construction reception center: 045-489-3085