Mechanism of water supply

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

As a result of a survey of the new method of direct pressure booster water supply (hereinafter referred to as "directly connected multi-step pressure booster water supply"), Water Works Bureau will accept applications for water supply equipment construction using this method from May 2011, and will expand the direct pressure booster water supply to high-rise buildings.
Directly connected pressure booster water supply, which is supplied directly from the water pipe to the faucet with a booster pump, is expected to provide safer and more delicious water, promote energy conservation, and reduce construction costs and maintenance of management fee. With the introduction of "directly connected multi-stage pressure booster water supply," the height limit, which was previously up to the middle and high floors, has been eliminated, enabling direct connection water supply to higher-rise buildings.

1. Supply of safer and more delicious water

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   Water is supplied directly to the faucet without going through the 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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   Construction costs related to the water supply equipment can be reduced compared to the water receiving tank type water supply, and the water receiving tank space is unnecessary, so the space can be used effectively.

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3. Reduction of management fee

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   Since there is no water receiving tank, maintenance of water receiving tank management fee is not required.

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4. Reduction of electricity costs and promotion of energy conservation

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   By effectively utilizing the water pressure of the water 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, thereby reducing power costs and promoting energy conservation.

• Construction costs for installing the booster pump and connection work to the management fee and distribution pipes will be borne by the installer.
• In order to maintain the proper function of the booster water supply equipment, it is necessary to have a regular inspection once a year by a manufacturer with specialized skills.

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

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

The upper limit of direct pressure type water supply was limited to the 4th floor, but from May 2011, the water supply capacity of the branching distribution pipe was set to a level that can supply water at 0.25Mpa.

0.25Mpa if the branching water distribution pipe corresponds to an area with a water supply pressure of 0.25Mpa or more, and if not, the water supply pressure (less than 0.25Mpa) responded by Water Works Bureau.

If you wish to receive direct pressure water supply of 3 stories or more, you will need to submit a water supply pressure survey request form to the Water Works Bureau Water Supply Center in advance to determine whether the planned water supply branch is an area with a water supply pressure of 0.25Mpa or more.

Tap water is once placed in a water tank, and this water is supplied directly with a pump, or sent to an elevated water tank installed on the rooftop to supply water.
In addition, the receiving tank system has a stock function that secures water in the event of a disaster such as a water outage due to an accident at a water supply facility or an earthquake.
In addition, the water receiving tank is to be maintained by the installer or manager at least once a year, such as inspection and cleaning.
※Please consult with Health and Welfare Center Environmental Sanitation Section in each ward about maintenance and management of the receiving tank, such as inspection and cleaning.
-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 work reception center: 045-489-3085