GB 50015-2019Standard for design of building water supply and drainage (English PDF)

Announcement No. 171 of 2019 of the Ministry of Housing and Urban-Rural Development

The Standard for design of building water supply and drainage is hereby approved as a national standard, numbered GB 50015-2019, and takes effect on 1 March 2020.

Articles 3.1.2, 3.1.3, 3.1.4, 3.3.4, 3.3.6, 3.3.7, 3.3.8, 3.3.9, 3.3.10, 3.3.13, 3.3.16, 3.3.20, 3.3.21, 3.6.3, 3.10.10, 3.10.13, 3.10.15, 3.10.22, 3.10.25, 3.13.11, 4.3.10, 4.3.11, 4.4.2, 4.4.3, 4.4.12, 4.4.17, 4.10.13, 6.3.9, 6.5.6 and 6.5.20 are mandatory provisions and must be strictly enforced.

The former Code for design of building water supply and drainage, GB 50015-2003, is repealed at the same time.

This standard is published on the portal of the Ministry of Housing and Urban-Rural Development (www.mohurd.gov.cn) and is published and distributed by China Planning Press, organised by the Standard and Quota Research Institute of the Ministry.

Foreword

This standard has been revised by the drafting group of the Standard for design of building water supply and drainage in accordance with the requirements of the Notice on issuing the 2012 plan for the formulation and revision of engineering construction standards and codes (Jianbiao [2012] No. 5) of the Ministry of Housing and Urban-Rural Development, following extensive investigation and research, a careful summary of practical experience, reference to the relevant international and advanced foreign standards, and wide consultation.

The main technical contents of this standard are: general provisions; terms and symbols; water supply; domestic drainage; rainwater; and hot water and drinking water supply.

The main technical contents revised in this standard are: the average daily domestic water consumption quotas for residential and public buildings have been supplemented; the classification of dormitories and the maximum daily hourly variation coefficient have been adjusted; the method of calculating the diameter of the outdoor water supply main of a sub-district has been adjusted; provisions have been added for calculating the design peak flow of the water supply mains of mixed-use buildings, or of different functional parts of the same building; the disinfection of swimming pools and aquatic recreation pools with bottled liquid chlorine has been deleted; the provisions on vacuum drainage have been deleted; safety provisions have been added for the ozone disinfection of swimming pools and aquatic recreation pools; provisions have been added on the grating covers of pool inlets, bottom return outlets and drains and on the water velocity through the gratings; the discharge capacity of floor drains has been supplemented; the maximum design discharge capacity of domestic drainage stacks has been adjusted; the load of drainage pipes discharging separately without ventilation has been amended; the conditions for fitting air admittance valves to drainage stacks of public buildings that are not extended above the roof have been added; the minimum width and depth of roof gutters have been supplemented; for roof rainwater, the maximum design discharge of the rainwater outlet and the pipe design calculation have been specified separately for single-outlet systems, gravity multi-outlet systems and full-bore pressure multi-outlet systems; the requirements of the sponge city concept for the rainwater design of building sub-districts have been added; the calculation of the rainfall duration for sub-district rainwater pipes has been amended to follow the current national standard GB 50014; the requirements for rainwater storage tanks in sub-districts have been supplemented; and provisions have been added for disinfection and sterilisation facilities in centralised hot water supply systems.

2 Terms and symbols

2.1.1 drinking water — domestic water whose quality complies with the national hygienic standard for drinking water, used for daily drinking, washing and similar domestic purposes.

2.1.2 non-drinking water — water other than drinking water, used for flushing water closets, washing vehicles, watering roads, irrigating green areas, making up the circulating water of air conditioning systems, and for landscape water bodies.

2.1.3 secondary water supply — the method of supplying water to users, or for own use, through storage and pressurising facilities and a pipe system, where the pressure or the quantity of drinking water required by civil and industrial buildings exceeds the capacity of the municipal public water supply network or of a self-built supply network.

2.1.4 hourly variation coefficient — the ratio of the maximum hourly water consumption to the average hourly water consumption.

2.1.5 maximum hourly water consumption — the hourly water consumption during the period of greatest consumption on the day of maximum consumption.

2.1.6 average hourly water consumption — the average hourly water consumption during the water-using period of the day of maximum consumption.

2.1.7 backflow pollution — the contamination of a domestic water supply system caused by back-pressure backflow or by siphonage backflow.

2.1.8 back-pressure back flow — the backflow that occurs when a change of pressure downstream of the water supply system makes the pressure at the point of use higher than the pressure at the point of supply.

2.1.9 siphonage back flow — the backflow caused by negative pressure in the water supply pipe, which draws in water or liquid mixtures from sanitary appliances or receiving vessels.