1.0.1 This specification is formulated to ensure the quality, amount and pressure of fine drinking water supplied by pipe system, and to make the system hygienic and safe, technology-advanced, economic and rational.
1.0.2 This specification is applicable to the design, construction, acceptance, operation and management of pipe system for fine drinking water in residential building, public building, etc.
1.0.3 Pipings and pipe fittings, equipment and auxiliary materials adopted for pipe system for fine drinking water shall meet the requirements of current relevant national standards, and the hygienic performance shall meet the requirements of the current national standard "Standard for Safety Evaluation of Equipment and Protective Materials in Drinking Water System" (GB/T 17219).
1.0.4 The design, construction, acceptance, operation and management of pipe system for fine drinking water shall not only meet the requirements of this specification, but also comply with those stipulated in the current relevant national standards.
2 Terms and Symbols
2.1 Terms
2.1.1 Pipe system for fine drinking water
The water supply system supplying fine drinking water for people after the raw water is subject to advanced water treatment and meets the standard.
2.1.2 Raw water
Domestic drinking water without advanced water treatment or any water with quality similar to that of domestic drinking water.
2.1.3 Product water
The fine drinking water (supplied for the user) which is processed with raw water through centralized treatment such as advanced water treatment and disinfection.
2.1.4 Instantaneous peak flow rate
The average flow rate of the specified time interval within the most intensive water consumption period.
2.1.5 Tab use probability
The ratio of the discharge time within the time interval from the first water discharge to the start of the second water discharge in two adjacent water uses during the peak water consumption period.
2.1.6 Circulating flow
The circulating water flow in the circulation system, of which, the value is determined according to the operation system and circulating time of the system.
2.1.7 Advanced water treatment
The further treatment process of raw water, which is capable of removing organic pollutants (including the substances that may lead to carcinogenesis, teratogenesis and mutagenesis, disinfection by-products), heavy metal, bacteria, virus, other pathogenic microorganism and pathogen protozoan.
2.1.8 Kinetic degradation fluxion process
The high-purity copper and zinc alloy filter material, which may, through electrochemical oxidation-reduction reaction after being exposed to water, effectively reduce or remove the chlorine and heavy metal in water and restrain the growing and reproduction of microorganisms in water.
2.1.9 Silt density index (SDI)
The value expressing the concentration and filtration characteristics of suspended solids and colloidal matters in inflow water.
2.2 Symbols
2.2.1 Flow rate
Qb - the design flow rate of water pump;
Qd - the maximum daily fine drinking water amount of the system;
Qj - the water yield of water purification equipment;
qd - the maximum daily fine drinking water quota;
q0 - the rated flow rate of tab;
qs - the instantaneous peak flow rate;
qx - the circulating flow.
2.2.2 Water pressure and head loss
∑h - the total head loss of pipeline from the most unfavorable tab to water purifying box (tank);
h0 - the minimum working pressure;
Hb - the rated lift of water pump.
2.2.3 Geometrical characteristics
V - the total volume of water supply and return system in closed circulation loop;
Vj - the effective volume of water purifying box (tank);
Vy - the volume of raw water regulating box (tank);
Z - the geometric height difference between the most unfavorable tab and the lowest water level of water purifying box (tank).
2.2.4 Calculation coefficient
k - the intermediate variable;
ki - the empirical coefficient of volume;
m - the tab use number during instantaneous peak water consumption;
N - the number of people served by system;
n - the number of tabs;
ne - the converted number of tabs;
p - the tab use probability;
pe - the new computational probability;
Pn - the simultaneous water consumption probability with the number of tabs not larger than m;
T1 - the circulating time;
T2 - the maximum daily design accumulated working time of water purification equipment;
α - the empirical coefficient.
