romanian standard sr 1343 1eng version

8/13/2019 Romanian Standard SR 1343 1ENG VERSION

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J:\English _STAS 1343\Romanian Standard SR 1343-1ENGVERSION.doc

SR 1343-1

ROMANIAN STANDARD June 2006

WATER SUPPLIES

CALCULATION OF DRINKING WATER SUPPLY QUANTITIES IN

URBAN AND RURAL SITES

Approved by the General Manager of ASRO on June 2006

APPROVAL

Replace SR 1343-1:1995

EQUIVALENCEOn the date of approval of this standard, there is no other

international or European standard dealing the same subject


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TABLE OF CONTENT

1. Object and scope of application............ ............................................................................. 3

2. Normative references ............................................................................... ......................... 3

3. Terms and definitions........................................................................................................ 4

3.1. Water Supply System................................................... .................................................. .............4

3.2 Users...............................................................................................................................................4

4. Water requirements and Water demand................................................... ......................... 5

4.1. Water Demand Components ............................................... .................................................. .....64.3. Components required to compute the water demand ......................................... .....................8

4.4 Self water demands (purveyors needs) for the water supply system components...............14

5. Hourly and daily variation coefficients of water requirement......................................... 15

5.1 Daily variation coefficient (kzi) .................................................. ................................................15

5.2 Hourly variation coefficient (kor)...............................................................................................15

6. Water demand for fire-fighting ....................................................................................... 17

7. FLOWS RATES SIZING AND CHECKING FOR WATER SUPPLY SYSTEM

COMPONENTS.................................................................................................................. 22

7.1 ............................................. ..................................................... .................................................. ...227.2 ............................................. ..................................................... .................................................. ...23

7.3 ............................................. ..................................................... .................................................. ...23

7.4 ............................................. ..................................................... .................................................. ...23

7.5 ............................................. ..................................................... .................................................. ...23

7.6 ............................................. ..................................................... .................................................. ...24

8. Synchronizing the flow rates with the continuous development of localities................... 26


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1. Object and scope of application

The present standard elaborates the underlying principles that lie at the base ofcomputing the water demands that must be provided by the drinking water supplysystem of a locality, as well as the design flows necessary to ensure a continuousand stable operation of the water system.

In the meaning of this standard the water consumers that can replace drinking waterwith non-potable water (industrial) to satisfy several needs, can and arerecommended to do this, in order to save water resources and to minimise thedemands on water supply system.

2. Normative references

This standard contains, by dated or undated references, provisions from otherpublications.

These normative references are cited at the appropriate places in the text and thepublications are listed hereafter. For dated references subsequent references to orrevisions of any of these publications apply to this standard, only when incorporatedin it by amendment or revision. For undated references the latest edition of thepublication referred to applies (including amendments).

STAS 1343/2 1989 Calculation of water supply quantities for industrial sector

STAS 1478-1990Sanitary Installation. Water supply for civil and industrialbuildings. Basic Design Prescriptions

SR EN 805-2000 Water Supply. Provision concerning the components andsystems located outside buildings.

SR EN 1508:2000 Water Supply. Provisions regarding the water storagesystem and components

SR 10898:2005 Water Supply and Sewage. Fundamentals and vocabulary.


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3. Terms and definitions

For the purposes of this Romanian standard, the terms and definitions given in SREN 805-2000, SR EN 1508:2000, SR 10898:2005 apply as well as the following:

3.1. Water Supply System

A water supply system is a system of structures, installations, services and actionsused to produce and distribute water to all or almost to all the population of a locality.

In its entirety, the system ensures water abstraction from a natural source, treatmentto achieve the required quality requested by the consumer, in compliance with thestandards in force, conveyance, storage and to deliver water to consumers withappropriate quality, quantity and pressure.

3.2 Users

Private consumers (residential inhabitants, school pupils, hospital bed, civil servantsfrom administration, hotels tourists and other types) or specific productionestablishments for which drinking water is utilized (tone of bread, hl of bottled juice,and tone of diary products)

The general scheme of a water supply system is as shown in Figure 1.


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Figure 1 - General layout of water supply system of a locality

LEGEND:

C catchment; structure and works that enable the abstraction of water in controlledregime;

SPi pumping stations, ensures the hydrodynamics conditions for water conveyancebetween the components of the system, whenever gravity flow conditions are notavailable;

ST Treatment plant ensures the correction of raw water quality to bring it up to therequired quality;

R storage construction; storage the water in order to:

! supply with water during system failures, upstream of reservoir;

! storage the fire-fighting flow;

! ensure the compensations between the R supply and R consumption.

A main pipe; ensures the water conveyance from catchment to reservoirs

RD distribution network; conveys water from the reservoir to every houseconnection with appropriate quality and quantity requested by users.

- - continuously measuring systems for water volumes, so that water balance within

the system is permanently controlled

4. Water requirements and Water demand

The water requirement represents the sum of water quantities delivered to eachuser/beneficiary through house connections.

The water demand is the water quantity which must be extracted from a source inorder to meet the water rational needs of the beneficiary/user.

" #C K K N N N N

p s g p ag ec Ri

$ % % & & &' . .

(1)

Where:

C water requirement;


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Ng water requirement for domestic use;

Np water requirement for public use;

Nag.ec. water requirement for commercial/industrial;

NRi water requirement for replenish fire suppression storage

Kp allowance required for covering real water losses within the water supplysystem up to the service connections;

Ks factor required for covering the water supply system needs (purveyors needs)such as: plant losses, reservoir washing and network distribution flushing;

4.1. Water Demand Components

Drinking water demand, partial or entirely includes:

a) domestic water demand: drinking, washing, bathing, cooking, laundry and dishwashing, house cleaning, flushing toilets, as well as for the animals aroundhouseholds.

b) water for public needs: all types of educational units, day nurseries, hospitals,policlinics, public baths, canteens, hotels, restaurants, shops, units where thesoft drinks are locally prepared, drinking water fountains;

c) drinking water for domestic use, within the industrial premises, if the potablewater is supplied by a centralize water supply system;

d) drinking water for other use purposes that cannot be independently supplied.Example of this category include: streets water spraying, streets and marketcleaning, lawn watering, sewage network flushing. For all these utilizations it isrecommended to use non-potable water from alternative untreated watersources (settled water from rivers, groundwater);

e) water demand for water supply system operation: preparation of coagulants,filter washing, main pipe and water distribution network flushing and reservoirswashing.

f) water demand necessary to cover unavoidable water losses within the

distribution system, due to failures and construction faults.

g) water demand for fire fighting when the distribution network is design toaccommodate the fire fighting water requirements.


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h)

4.2. Specific flows for water demand

In water use there is hourly, daily, weekly and yearly variations. In order to take intoaccount these variations the following specific flows shall be used:

! Average daily demand (Qzimed) is the average daily rate of flow of water in ayear that must be supplied by the water system, m3/day:

Qzimed ' '$ $

()

*+,

-%$$

n

1k

m

1i

s (i)qN(i)1000

1

365

YearlyVol. (2)

Maximum daily demand (Qzimax) is the largest daily rate of flow of water in a year thatmust be supplied by the water system to meet customer demands, m3/day:

Qzimax = ' '$

()

*+,

-%%

n

k

m

zis iKiqiN1

)()()(1000

1 (3)

Peak hour demand (Qorarmax) is the largest hourly rate of consumption during peakconsumption day (days), m3/h:

Qormax= ' '$ $

(

)

*+

,

-%%%%

n

k

orzi

m

i

s iKiKiqiN

1 1

)()()()(

24

1

1000

1 (4)

Where:

N(i)number of consumers ;

qs(i) specific flow: average day demand required for a user, l/ per capita/ day;

Kzi(i)dayly variation coefficient; expressed as the ratio of largest daily rate deviationvalue of flow to average daily rate of flow, dimensionless;

Kzi(i)= )(

)(max

iQ

iQ

zimed

zi

(5)

Korar(i), hourly variation coefficient, expressed as the ratio of peak hour demanddeviation value of the consumption to average hour flow, during peak consumptiondays, dimensionless;


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Kor(i) =)(

)(max

iQ

iQ

ormed

or (6)

Qormed(i) = 24maxzi

Q

(7)

In the equations (2), (3) and (4), the significations of indexes are:

k refers to the water requirement category (public and domestic requirement);

i refers to the type of consumer and the specific flow related to the type of consumer.

4.3. Components required to compute the water demand

4.3.1 Specific flow rate for domestic demand (qg)

The values for specific flow for domestic demand (qg) can be adopted according toTable 1. Other values can be adopted whenever the figures are justified by means ofspecific designated studies.

Table 1

AreaNo.

Areas or localities classified depending onsanitary-engineering installation endowment

qg(i)l/percapita/ day

Kzi(i)

1Areas where water is supplied with stand pipes

placed on streets without sewage systemN1)

50 1.50/2.00

2Areas where water is supplied with stand pipesplaced in yards without sewage system

5060 1.40/1.80

3Areas with residences having plumbing facility wherethe hot domestic water is locally prepared

100120 1.30/1.40

4Areas with block of flats having sanitary-engineeringinstallation where the hot domestic water is suppliedby a Central Heating Systems

150180 1.20/1.35

Note 1:

The values of qg(i)can increased depending on:

! Size area or inhabited centre, population density (p/ha) and type of dwellings;


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4.3.2. Specific flows rate for public needs (qp)

The water requirement for public consumers are computed analytically by the

addition of all water quantities necessary for each userTable 2

Flows l/unit/day

No. Consumption category Unit

Range of values

1 Airport Traveler 7 15Client 5 20

2 BarEmployee 40 60

3 Offices Employee 30 60

Consumer 15

304 Caf-bar Employee 30 455 Camping Person 110 1906 Rest houses Person 200 4007 Guest house Person 80 110

Employee 25 508 Commercial centre Parking place 5 7.5

User 250 3009 Clubs

Employee 40 60Toilets 1500 2000

10 Commercial centre (mall, storage)Employee 30 45

11 Dormitories building Person 75

100Client 150 25012 Hotel Employee 25 50

13 Hotel (resort) Person 150 250Convicted 300 600

14 PrisonEmployee 20 40Consumer 5 10

15 Small shopEmployee 30 45

with kitchen Seat 300 60016 Motel

without kitchen Seat 200 500

17 Pension Person 200

300Consumer 15 30

18 Swimming poolEmployee 30 45

19 Restaurant Table 7 1520 Cafeteria Consumer 5 10


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Employee 30 4521 Refectory Served meal 20 4022 Boarding school with canteen Pupil 200 400

with showers, gyms,

snack Pupil 50

80only with snack bar Pupil 40 6023 Schoolwithout gym and snackbar

Pupil 20 30

Vehicle 25 5024 Auto service

Employee 35 60

25 Laundry(clothes) Machine 2000 2500

Bed 400 60026 Hospital

Employee 20 4027 Daily Camp (without meal) Person 40 60

28 Theatre Seat 5 1029 Terrace Seat 50 7530 Camp land Person 75 10031 Tourist areas Visitor 15 30

Note 1:

These orientation values must be adapted considering:

! Location area of consumption category;

! Status of area: urban, rural, resort, shoreline or mountains;

! The quality category of supplied services;

! Consumers traditional behavior in the location area


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4.3.2.1 Equation to compute water quantities:

a) Average daily flow

Qzimed= '$

%$m

i

pini qNYearlyVol

1

)(1000

1

365

. (8)

Where:

Qzimed- average daily flow, m3/day

Nninumber of units of a certain public category;

qpispecific flow, l/unit, day

b) Daily variation coefficients are determined for each unit depending on theactivitys deviations against average; they can be adopted similar to theinhabitation area where the public user is located (see Table 1). The maximumdaily flow for public users shall be calculated similar to equation (3).

c) Hourly variation coefficient is determined for each water user based on theoperating program, in the days in which the largest daily consumption isattained.

For the entire area or the locality the hourly variation coefficient is set as a weightedaverage of each category which is to be used.

KK T

Tormed

ori F i

F i

$

%''

(9)

Where

Korihourly variation coefficient for a certain consumption category;

TFidaily operating time assigned to each consumption category;

The peak hour coefficient shall be similar calculated by using (4)

d) When analyzing the future development of the water supply system one musttake into consideration the decrease of specific public consumption (~ 10% in20 years) whilst the endowment and the reliability of installations will beincreased.


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4.3.3 Water requirements of uses which do not require drinking water

Ensuring of water requirement by replacing (substitution) of drinking water must bedone independent of the water requirement intended for human consumption, by

using:

! Settled water from DWTP;

! Water from the accumulation lakes, located in the close proximity oflocalities;

! Non potable water from the groundwater sources located in theinhabited area.

The assurance of this water requirement shall be done through separate networks.

Under special circumstances (established by the designer and water operator andwith local authoritys approval) the water from the distribution network intended forhuman consumption may be used.

4.3.3.1Water requirement for lawn watering (qsv) shall be analytically calculated by

considering a specific norm of 5.25.1 .$svspq l/m2/d; the differentiation shall be done

depending on:

! Locality climate(area);

! Altitude, geographical area, endowment level, lawn designation

4.3.3.2. Water requirement for streets spraying and cleaning markets, maintenanceof the urban areas of general interest is computed analytically based on a specific

norm of (1. 5 5) l/p !d:

! When adopting the value of the specific norm one must take into considerationthe occupied ratio and land using of maintained areas, as well as thepopulation density and both demographical and the ecological parameters

! For commercial establishments and markets a specific norm of (1 - 1.5) l/m/dmay be adopted.


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4.3.3.3 Water requirement for sewage network maintenance (qc) is analyticallycomputed, depending on:

! the scheme and the sewage system;

! number of cleaning manholes and the length of the sections where the self-cleaning velocity cannot be achieved;

! sewage network status.

The water requirement shall be adopted by the designer, together with the networkoperator. The water must be ensured from independent sources of water supplysystem intended for human consumption.

4.3.3.4Process water requirement for industry (qi) shall be analytically computed incompliance with the process norms and working capacity of each unit. The waterrequirement supplied by the drinking water network in order to meet thehygienic/sanitary needs of the staff shall be calculated similar to water requirementfor public use.

This is computed according to Tables 1 and 2 from STAS 1478 90.

4.4 Self water demands (purveyors needs) for the water supply

system components

Demands shall be analytically computed, based on the following:

a) Treatment process and DWTP components; allowable process losses withinDWTP should not exceed 6 % of the produced water quantity; cases in whichthe recirculation of the supernatant from the settling tanks and filters washingis ensured, then the losses can be reduced up to 3%; the increment forgroundwater shall be assessed from case to case;

b) Water requirement for periodical cleaning of the distribution network shall be

done according to the operative plan for cleaning the network sections; thisdepends on pipe material, water quality and the ability of materials to formbiofilm; the water quantities used shall not exceed (12) of the distributedwater volume;

c) Water requirement for cleaning and washing the water reservoirs of the


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system; once or twice a year, each compartment of the reservoir will beemptied, washed and properly disinfected; water quantities necessary toperform the washing operation should not exceed 0.4 % ... 0.5 % of the watervolume annually consumed.

4.4.1 The technically allowable water losses in the distribution network areconsidered a water requirement and shall be treated as such. For the new distributionnetworks (< 5 years) it is projected that the losses shall not be higher than 15 % ofthe distributed water volume (Kp=1. 15); these may be a result of constructionimperfections, daily pressure variations, defected materials.

For the existing distribution networks being under modernization/extension process,the losses can be up to 35 % (Kp=1,.35). In case of losses percentage higher than 35% which is abnormal considered, adequate measures shall be readily available

5. Hourly and daily variation coefficients of water

requirement

5.1 Daily variation coefficient (kzi)

The daily variation coefficient (kzi) shall be established for each type of consumer. Inthe Table 1 are shown the orientation values for the daily variation coefficient uponareas and localities, depending on the endowment level with sanitary-engineering

installation.

Generally, the daily variation coefficient tends to decrease with locality (area) sizeand with the increasing of the endowment levels.

5.2 Hourly variation coefficient (kor)

The hourly variation coefficient (kor) is to be established for each type of waterdemand. Unless there are no other figures given by specific studies the ones fromTable 3 may be adopted.


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Table 3

Note 1: When the water distribution is not incessant done (abnormal situation) butbased on an own supply schedule, the korcoefficient may be increased upon justifiedcalculation. But the intermittent water supply should be assumed as temporary.

Note 2: For intermediate values of number of inhabitants the korcoefficient shall becomputed by interpolation, whilst the number of inhabitants decreases, the value ofthe hourly coefficient variation increases (the maximum value is 5.0).

Note 3: The coefficient shall be determinate depending on the number of inhabitantsN(i) of each network pressure zone, the maximum flows resulted being properlysummed.

Note 4: For large water networks, which serve more than 100.000 inhabitants it isrecommended to use an hourly variation coefficient that is proportional with thenumber of users projected, downstream of computed section.

Note 5: In the Annex 2 of the present standard are pre-annexed, based onmeasuring after [1] the hourly consumption variations in a working day (t>18C) forvillages, small, medium and large cities. It can be observed that the variation of thehourly coefficient range from 2.88 for villages to 1.368 for large cities. In the sameannex is given an empiric equation, designed on statistical basis, in order to establishthe maximum daily flow (implicit the global daily variation coefficient), depending onthe number of inhabitants.

No. of inhabitants of the locality/pressure zone considered

Kor

000.10/ 2.003.0015.000 1.302.0025000 1.301.5050000 1.251.40100000 1.201.30

000.2000 1.151.25


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6. Water demand for fire-fighting

Whenever a supply system is designed, one must provide proper facilities in order toensure the water quantities required for fires suppression.

The fire suppression may be performed by using interior fire hydrants, installed insidebuildings and exterior fire hydrants installed on the water distribution networks.

For special buildings (theatres or libraries) or industrial premises, special devicessystems for fire fighting must be designed, in strictly compliance with the technicalregulations in force.

The water quality for interior hydrants should be the same as the distributed water.

Generally, exterior hydrants use the water from distribution water networks.

In special cases, for suppression an external fire, may be used water of other quality,supplied by independent facilities (own water cistern/cars, water storage, separatenetworks). This situation implies the existence of a water network designated in thisscope.

The number of theoretical simultaneous fires shall be adopted depending on localitysize, as described in the Table 4.

The flow for fire fighting by means of interior hydrants Q ii(number of jets and the type

of buildings equipped with interior hydrants) as well as the flow for special devices(Qis) shall be adopted in compliance with STAS 1478-90.

Table 4

Hydrant flow(l/s)No. of

inhabitants

N=N(i)

No. ofsimultaneous

fires(14) floored

buildings

Buildingsexceeding 4

floors

000.5/

1 5 10

500110000 1 10 15

1000125000 2 10 15

2500150000 2 20 25


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50001100000 2 25 35

100001200000 2 30 40

200001300000 3 40 55

300001400000 3 - 70

400001500000 3 - 80

500001600000 3 - 85

600001700000 3 - 90

700001800000 3 - 95

8000011000000 3 - 100

Note 1: The figures given in the Table 4 are applicable to separate districts as well,separated from the inhabited centre by a non built-up area. In this case 1N(i)represents the number of inhabitants of each district.

Note 2: The flow for external fire, Qieand the number of simultaneous fires, n forinhabited centers having more than 1000000 of inhabitants shall be determinedbased on special studies.

Note 3: Positioning of simultaneous fires in the perimeter under consideration in

order to size the distribution network shall be done so that a fire theoretically shallbe allocated to an area inhabited by maximum 10000 inhabitants.

Nota 4: In case of networks with pressure zones, one must analyze the variant inwhich every zone operates independently in case of fire; the largest flows resultedfrom the analysis will be adopted. The number of fires shall be determined for theentire locality. Attention should by paid to Note 1 and Note 3.

Note 5: For localities under 5000 inhabitants the provisions GP106-04 Annex IVshould be applied, approved by MTCT 15/02/2005 and published on 21/04/2006 inthe Official Gazette Part I No.338 bis.

Unless there are not available special studies, the flow of exterior hydrants (Q ie) maybe adopted by using the figures shown in Table 4.

The theoretical time of hydrants operation shall be determined according to STAS1478-90. Theoretical operating time assigned to exterior hydrants is Te = 3h

When the distribution network supplies business enterprises located in the residential


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area, the number of simultaneous fires should be considered as shown in Table 5 ofSTAS1343-1/2006. In case of industry the provisions described both in STAS1342/2-89 and 1478-90 should be applied, unless other figures are justified. The fireflow for premises must be adopted depending on the industry danger, in compliance

with STAS 1342/2-89 and STAS 1478-90 or based on precise data provided by theprocess specialist.

Table 5

Number ofinhabitants ofa locality (N)

Area of theplants, S,

(ha)

No. ofsimultaneous

fires (n)

Procedure for consideringsimultaneous fires

< 10000


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Note: If in between the commercial establishment and locality there is always a greenland of 300m, than those (locality and industry) should be separately analyzed.

The flows required for interior and exterior hydrants are provided by the designated

volume stored in the reservoir, thus:

a) (Vi) water demand for effective fire suppression;

Vi=' ' ' %&%&%

n n n

siseieiiij TQTQTQn1 1 1

6,36,36.0

(10)

Where:

Vistored capacity, in m3;

n no. of simultaneous fires for which the suppression is made from outside by usingexterior hydrants;

njno. of simultaneous jets that are compulsory for the building under consideration;

Qiiflow supplied by the interior hydrants, in l/s, design criteria are described inSTAS 1478-90.

Titheoretical operating time assigned to interior hydrants, minutes, design criteriaare described in STAS 1478-90.

Qie- flow supplied by the exterior hydrants, l/s;

Te- theoretical operating time assigned to exterior hydrants, hours; Te=3h

Qisflow for fire suppression by using special devices whose operating time isTs[hours], should be established in accordance with STAS 1470-90, l/s.

b). the water demand for user consumption during the fire suppression is:

Vcons= eormaxTQa

[m3] (11)

Where: Vconsis the water volume used by the consumer, m3;

a=0.7 for p bar7.00 ; a=1 for high pressure networks;

Qormaxrepresents the hour peak flow for the area or locality where fire is suppressed.

The total fire suppression storage water protected is:


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VRI= Vi+ Vcons (12),

The replenish fire suppression storage after it is depleted shall be calculated with theequation:

QRI=

24xT

V

ri

RI

, m3/day

Triis the time required for replenish the fire suppression storage and should beconsidered as shown in Table 6 of STAS1343-1/2006.

Table 6

Localities and Industrial Areas interconnected with localities Tri [h]

Localities 24

A+B 24

Qie>25l/s 24C having:

Qie / 25l/s 36

Qie>25l/s 36

Industrial areas with buildings classifieddepending on fire hazard

D and Ehaving:

Qie / 25l/s 48

NOTE 1: When Qie"10l/s and the flows are insufficient at source, thetime for

replenish fire suppression storage Trican be increased up but no more than 72h.

NOTE 2: When the flow from sources cannot satisfy the suppression storagereplenishment in the maximum duration Trias stipulated din Table 6, the extension ofthese durations are accepted but only if the volume of fire suppression storage V riisincreased with the amount that cannot be ensured in the standardized time.

NOTE 3: The water suppression storage shall be kept in one or more compartmentsso that the entire volume for fire suppression shall be permanently available.


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7. FLOWS RATES SIZING AND CHECKING FOR WATER

SUPPLY SYSTEM COMPONENTS

Figure 2 Flows rate sizing and checking for water supply system components

7.1All units encompassed from catchment to Water Treatment Plant are to be sizedby using the following formula:

RIspzispIC QKKQKKQ %%&%%$ max (14)

Where:

Kp water demand augment coefficient required for losses within the water supplysystem components;

Ks dependent coefficient required for covering the water supply system needsuch as: water farm operating, reservoir washing, network distribution flushing etc.;


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Qzimax is the total day peak amount, m3/day, in order to entirely fulfill the waterdemand;

QRI flow required to replenish fire suppression storage.

7.2 All water treatment plant components should be sized at Q ICas describedabove.

7.3All the components located between water treatment plant and reservoir (mainpipes systems) shall be sized for the following flow:

sK

ICQ

ICQ $'

Where the fire flow exceeds 20l/s the connection reliability between reservoirs anddistribution should be checked.

7.4 The reservoirs should have sufficient capacity for:

! Fire suppression storage protected storage;

! Peak balancing storage (hour balancing volume and if possible, day balancingduring the week);

! Emergency storage protected, required for supplying demand in event ofpipeline or equipment breakdowns or maintenance shutdown.

The minimum volume of the reservoirs should be at least 50% of averageconsumption and must be provided by the operators who exploit centralized watersupply systems, according to laws in force.

When the topography is suitable, the reservoirs must to ensure the pressure in thedistribution network.

7.5 All the units located downstream to reservoir should be calculated using the

equation:

ii

n

jporpIIC QnKQKQ '&%$1

max (16)

Where:


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njQii- number of jets and the flow of the interior hydrants (Q ii) assigned to thesimultaneous fires which are suppressed from exterior (n);

Kpcoefficient defined at item 4.4. The coefficient includes the water for periodical

flushing of distribution network (12) and for reservoirs (0.4%...0.5%)acc. 4.4 b,c

For this flow value all users considered (including interior hydrants) can use thewater in standardized quantity and according to designed scheme (directly to thenetwork pressure or by intermediary means)

In case of a network having several pressure zones the flow njQiishall be computedfor each zone with the adequate hourly variations coefficients (Ko) and njQii flow,depending on the endowment levels of buildings with interior fire hydrants.

7.6 The checking of water distribution network should be made in two differentcircumstances, namely:

! when using water for suppress the fire by using the interior hydrants for onefire and, exterior hydrants for the other (n-1) fires;

! in case of suppress the fire from outside using only the exterior hydrants forthe all n simultaneous fires.

7.6.1 Regardless the standardized position of the exterior hydrants, when the nsimultaneous fires occur the minimum pressure of the network must be:

! minimum 0.7 bars for low pressure networks (pressure zone)

QII(V)= aKpQormax= 3.6n KpQie, m

3

/h, where QII(V)is the checking flow

! the pressure of hydrants free use in case of high pressure networks for theflow

QII(V)= KpQomax+ 3.6 n KpQie, m3/h, where QII(V)is the checking flow

In order to assure a proper operating of the indoor hydrants a checking should bemade for any inner fire, if the pressure required is available in any circumstances,including the case when the other theoretically simultaneous fires are suppressedfrom exterior.

QII(V)=a KpQomax+ 3.6 Kp(nijQii))max+ 3.6 (n-1) KpQiem3/h,

(nijQii)maxis the major inner fire that could occur in the zone or locality underconsideration.

7.6.2 For the important networks (looped networks having more than 50000inhabitants) the operating reliability must be checked in case of failures occurred on


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the main trunks. During the failure duration one must check:

! Operating parameters of the networks in case of fire, with to goal of checking

the Qiiconveyance capacity and to ensure the pressure in the zones under

considerations.

! The assurance of normal pressure for network operating, while the damaged

sections is out of service and blocked for the remainder users.

! Eliminate the risk concerning the lack of water required to supply vital

consumers.

7.6.3 Depending on local circumstances, the designer, together with the operator

may justify other required checking (to verify if the buffer tank is filled and the

network is supplied only by the buffer tank, controlled supply between the networks

of two adjacent pressure zones, operation with a only one supply source)

7.6.4For very developed networks (localities with more than 300000 inhabitants) it is

recommended to verify the network, for the sizing hypothesis considered and to

determine the real - time of water flow (water age) in the network, linked to water

quality.

7.6.5 It is recommended to place fire hydrants on the main pipes (trunk) of the

distribution network, based on an agreement concluded between the designer,

operator, with the approval of the specialized institutions, regional commandment for

emergency situations and local public authorities. In addition, this will allow the

possibility of supply the moto-pumps of fire brigade directly from the reservoir within

the water supply system.


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8. Synchronizing the flow rates with the continuous

development of localities

The design of components must take into account, as structural and technologicalprocess point of view the possibility of system development, by using the sameconfiguration (catchment extension, DWTP upgrading, to double up the main pipe orby including intermediary pumping stations). Synergy

The water supply systems must to adapt to all modifications and developments thatmay arise in the supplied area or locality, by taking into account:

! Social and urban development prognosis for a time horizon of 25 years;

! Increasing of comfort level in dwellings and to public users (centralizedinstallations for hot domestic water and heating ), endowment for cooking andcleaning, sport facilities endowed with showers, swimming pools, etc);

! The development of the city by increasing the number of users(inhabitants orpublic users);

! Water losses reduction within the distribution network under rehabilitation, upto values of maximum 2022%;

! At global level, the specific average requirement tends to decrease (or toremain constant) because of technological progress and increasing of life

quality; social environment begun to appreciate the great importance ofdrinking water and its saving.


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ANNEX 1

(For information only)

The variation of specific consumption according to IWA data(International WaterAssociation), centralized at the IWA congresses Paris2000, Berlin 2001, Melbourne2003

Country Austria BelgiumGreat

BritainGermany France Luxembourg Holland Spain Sweden

Specifc

consumption

[dm3/capita,day]

131-271 108-166 132-267 146-196 1501) 171-259 159-195 150-200 175-.350

NOTE: These values encompass: domestic consumption, public and economicenterprises, supplied with drinking water

2 In the standard SR EN 805 Annex A is specified:

When there is not available better information, the total water requirement mayrange from 150 to 250l/capita/day

3 In Romania, according to ARA Report (Romanian Water Association)-2000, page44, is specified: for the urban area the domestic consumption is 256,1l/capita/day,the public consumption is 75l/capita/day

In 2004 and 2005 has been reported by several important cities (Timisoara, TarguMurs) mean consumption for domestic purpose such as 115120l/capita/day.


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ANNEX 2

(For information only)

1. Hourly consumption in a working day (exterior temperature 18C)

HourVillage

%Small town

%Medium town

%Big town

%0-1 1,0 2,0 1,5 2,61-2 0,5 1,5 1,5 2,42-3 0,5 1,0 1,5 2,2

3-4 0,5 0,5 1,5 2,1

4-5 0,5 0,5 2,0 2,25-6 6,5 1,5 3,0 4,26-7 12,0 2,5 4,5 5,37-8 8,5 3,0 5,5 5,78-9 3,5 3,5 6,0 5,69-10 3,0 4,0 5,5 5,4

10-11 3,0 5,0 6,0 5,311-12 4,5 7,0 6,0 5,312-13 10,0 9,5 5,5 5,213-14 9,0 10,0 5,5 5,114-15 1,5 8,5 5,5 4,915-16 1,5 5,0 6,0 4,5

16-17 2,0 3,5 5,5 4,217-18 2,0 3,0 6,0 4,718-19 3,0 5,0 5,5 5,019-20 5,5 8,0 5,0 5,020-21 9,0 6,0 4,0 4,221-22 8,5 4,0 3,0 3,3

22-23 3,0 3,0 2,0 2,923-24 1,0 2,5 2,0 2,7Total 100% 100% 100% 100%

According to [1], the equation used to compute the quantities of daily maximumconsumption (Q

zimax) is:

Qzimax0,37986E1,01939[m3/d] (2.1)

Where;

Qzimaxis the maximum daily flow, [m3/d]


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romanian standard sr 1343 1eng version

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