Direct Water Supply Connection

There are two methods of supplying tap water. One is to store water temporarily in a receiving tank; the other is to use a direct connection between the water conduits and water taps that bypasses the receiving tank.

In order to eliminate sanitary problems with small receiving tanks that are insufficiently well managed and to improve its water supply services, the Waterworks Bureau has expanded the scope of direct water supply connections. These connections are available in the following two types.

Direct water supply system without receiving tank

This method is applicable to buildings up to three stories tall, if the following conditions are met.

• Meter diameter of 75 mm or less
• Water supplied to a height of 8 m or less
• Building where this method is shown to be feasible by hydraulic calculations

For applications received after December 1, 2005, a direct water supply system without receiving tank can be installed on roofs of buildings up to three stories tall, if the following conditions are met.

• Water supply equipment that contributes to improvement of the city environment is installed on roofs of buildings up to three stories tall; and hydrologic calculations show that this method would be feasible for such buildings.

For applications received after October 1, 2007, a direct water supply system without receiving tank can be installed in buildings up to four or five stories tall in some special cases where the distributed water pressure is high in some areas.

Booster-Pump Water Supply System without Receiving Tank

This method may be used if the following conditions are met.

• Meter diameter of 75 mm or less.
• Buildings that can be supplied with water by using direct water supply booster equipment with a water pressure of 0.75 MPa (7.6 kgf/cm2) or less.
• No sections for which the intended use is unclear at time of application.

The system can be used in buildings up to about 15 stories high, but as the maximum momentary water supply volume and the scale and configuration of piping differ for individual buildings, the practicality of use must be confirmed by hydraulic calculations.
*Cost of pumping equipment for the direct water supply system without receiving tank, as well as its maintenance and inspection costs, are all borne by the customer.

[Page Expanding Direct Water Supply Facilities under Before Water Reaches the Tap Water Supply under Guide to Waterworks on the Osaka City Waterworks Bureau Website ends here.]