water plumbing in txt

7/30/2019 water plumbing in txt

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Course DescriptionThis course concentrates on the design & calculations of sanitary systems, usedin building applications. This course is prepared for practicing mechanical andcivil engineers, maintenance personnel, & for students undertaking a final yearproject. This course would be helpful for engineers who are involved in plumbingsystems, and want to get a better understanding of pipe sizing, venting systems, rain water systems & sewer pumps. The course provides an opportunity to review, refresh and enhance the attendants' sanitary knowledge, and to learn how to read and draw the mechanical plans & specifications required for order of engineer in Lebanon. It also provides an opportunity to interact, learn from the instructor and from each other, and to implement the troubleshooting techniques. Specialattention will be paid for sewage pumps types & selection applied in buildings and other applications.


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Mechanical Engineering short-courseThis course is prepared for mechanical and civil engineering students , at Beirut Arab University. This course concentrates on the design & calculations of Plumbing systems, used in building applications. Course duration is 12 hours 6 hoursfor cold & hot water distribution systems in building. 6 hours for sanitary systems in building. By Dr. Ali Hammoud Associate professor in fluid mechanics & hydraulic machines


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OBJECTIVES Before an engineer sets out to design the plumbing services of any project, it is necessary that he has well defined aims and objectives in order toinstall an efficient and economical plumbing systems. These can be defined as follows: 1- Supply of Water a- Provide Safe Drinking-Water Supply b- Provide an Adequate Supply of Water 2- Fixtures units a- Minimum Number of Fixtures b- Quality Sanitary Fixtures c- Water Trap Seals d- Fixture spacing


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Table of Contents part 1Symbol & legendDescription of Architecturedrawings of the project

Design of Risers Daily W. Requirement Load Values W.F.U. Pipe sizing Types ofmps Circulating Pump Pipe sizing Electrical W. heater Water storage heater Inntaneous or semi-inst. heaters

Cold water distribution system Calculation Hot water distribution system CalculationDr. Hammoud

Drawing of water distribution inside the flats Questions


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Symbols & legendsSS WS VS V SV RW RWS SOIL STACK WASTE STACK VENT STACK VENT STACK VENT RAIN WATER RAIN WATER STACK

CW SW PW HW HWR TS WTR DR F.F G A V FOS

COLD WATER SOFT COLD WATER POTABLE WATER DOMESTIC HOT WATER DOMESTIC HOT WATER RETURN TANK SUPPLY WATER DRAINAGE FIRE FIGHTING GAS COMPRESSED AIR VACUUM FUEL OIL SUPPLY


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CI GS BS PVC C-PVC PVC-U P.P P.P.R PE-X PE-X / AL / PE-X CU P.E H.D.P.E

CAST IRON PIPE GALVANIZED STEEL PIPE ( SEAMLESS & WELDED ) BLACK STEEL PIPE ( SEAMLESS ) POLYVINYLCHLORIDE PIPE CHLORINATED POLYVINYLCHLORIDE PIPE UNPLASTICIZEDPOLYVINYLCHLORIDE PIPE POLYPROPYLENE PIPE ( DRAINAGE ) POLYPROPYLENE RANDOM PIPE ( WATER ) CROSS-LINKED POLYETHYLENE PIPE PE-X , ALUMINUM , PE-X ( TRIPLE LAYER) PIPE COPPER PIPE POLYETHYLENE PIPE HIGH DENSITY POLYETHYLENE PIPE

AWC EWC B LAV S SH KS BT DF HB FT FV

ASIATIC WATER CLOSET EUROPEAN WATER CLOSET BIDET LAVATORY SINK SHOWER KITCHEN SINK BATHTUB DRINKING FOUNTAIN HOSE BIB FLASH TANK FLASH VALVE


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CO CCO FCO J.B RVC MH FHC WS WH

CLEANOUT CEILING CLEANOUT FLOOR CLEANOUT JUNCTION BOX ROOF VENT CAP MANHOLE FIREHOSE CABINET WATER SOFTNER WATER HEATER

FA TB IW UT UG UCL I.F.S B.F.S LL HL UP DN FM NTS

FROM ABOVE TO BELOW IN WALL UNDER TILE UNDER GROUND UNDER CEILING LEVEL IN FLOORSLAB BELOW FLOOR SLAB LOW LEVEL HIGH LEVEL UP DOWN FROM NOT TO SCALE


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PLUMBING FIXTURES


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Project descriptionThe project consist of two blocks A and B and a common Ground floor & 0ne Basement Block A consist of 18 floors and block B consist of 17 floors.. The design drawing of the two blocks are identical. Flat area is about 700 m2. Each flat consist of one master bedroom, three bedrooms, one living room, one dining room, onekitchen , maid room and six bathrooms. Floor to floor height is 3m Water supplyfrom city main is irregular and we have to rely on two well pumps for water domestic use which have a capacity of 5m3/hr each. However drinking water is supplied from city main water supply. The city water pressure is insufficient. (a) Work out daily water requirement, underground and overhead tank capacity (b) Assuming indirect water supply system .Calculate the size of the the main riser pipe from the underground reservoir up to overhead tank and the pump duty. (c) Assuming two downfeed risers from the overhead tank for each flat as indicated in the typical floor drawing. .Calculate the pipe diameters and branch lines for these risers. (d) Design the cold and hot water distribution system inside the flat. (e) size the pressure vessel of the top floors and the corresponding pump duty.


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Block A 18 floors

Block B 17 floors

Refer to your drawing & follow the lectureTypical floor


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Heater 1 Heater 2Riser 1 B6 B1 Riser 2 B2 B4 B5

B3

Riser 2 supply cold water to B1 + B2+ B3+ B4

Riser 1 supply cold water to B5 + B6+ Kitchen


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Cars

Ground floor


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Water storage tanks

Basement floor


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HOW TO READ AND DRAW THE WATER DISTRIBUTION SYSTEM INSIDE THE FLAT .


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EXAMPLE OF WATER DISTRIBUTION SYSTEM INSIDE BATHROOM GALV. STEEL PIPES


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DETAIL OF WATER DISTRIBUTION SYSTEM INSIDE BATHROOM P.P.R PIPES


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DETAIL OF WATER DISTRIBUTION SYSTEM INSIDE BATHROOM PEX OR PEX AL-PEX PIPES


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Solution of a ,b & c

Schematic water risers diagram for Madam Cury project


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Solution of (d) Two Electrical water heaters & two water risersElectrical W. Heater 2

Madam Cury project water distribution system E.W. for typical floor

Heater 1


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Solution of (d)

Madam Cury project water distribution system for typical floor Another version

with single large Single Water heater+ boiler


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Up to now !! Before starting the calculation of the plumbing project . Student should be able to read and understand all the Architecture drawings of the project entitled Madam Curry .


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Chap.2

Cold & Hot water distribution systems


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Calculation Of W.D. Systems Design Of W.D. Systems

Daily Water requirement Load Values Pressure requirement

Pipe sizing

selection Pump Max Zornada (2002)

Slide 25


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Distribution systems

No pumps

Direct supply system: conveys water directly from water mains to the point of usage without any transit water storage tanks Direct supply system (without storagetank)


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Direct supply system (with storage tank)


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Distribution systemsIndirect supply system: conveys water from water mains to the point of usage through a transit water storage tank

Indirect supply system (with sump and pump)


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Indirect supply system (with pneumatic vessel)


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Comparison of direct and indirect water supply systems Direct supply Indirect supply

- Less pipe work, smaller or - More pipe work, large water no water tank storagetank - No storage to satisfy peak - Water storage to meet peak demand period demand - Risk of contamination and - Less risk of adverse effects pressure fluctuation of mains by water mains - Not feasible for high-rise - Can be used in high-rise buildings due to main pressure buildings


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Water Distribution Systems Up to 10 floors Bldg

Indirect water supply to flats

Direct water supply to flats


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Distribution Systems Buildings above 20 floors

Pressure vessel

Pressure Reducer

Break -Pressure reservoires

Break- pressure ( Branch water supply )

Direct supply ( Booster ) or frequency inverter

Indirect water supply to flats

Direct water supply to flats


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Multi-pipes system is always preferable

Muli-pipes system

Underground Tank

Each flat has its own inlet flow pipe


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Water storage in buildings

Domestic & Potable Irrigation

Fire fighting


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Domestic water storage in buildings

Underground tanks

Roof tanks


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Storage of waterWater is stored in buildings due to the irregular supply supply of city water .Normally water is stored in basement with pump transferring water to roof tanks .Roof tanks could one single tank for the whole building or separate tanks for each flat. As shown in the following pages ,water tanks are provided normally with float valve, drain valve, discharge valve , overflow and vent pipe.


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Underground water storage Pumps Tanks Connections


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Roof TanksRoof tanks should be elevated enough above roof level to have enough pressure for the upper apartment , otherwise booster pump is needed.

Material of roof tanks 1-Concrete tanks. 2-Galvanized tanks. 3- PPr tanks. ( most popular these days) 4- Fiberglass storage Tanks


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Concrete Roof tanks


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Galvanized Roof tanks

Ref [4]


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P.P.R. Roof tanks


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Riser diagram


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Riser diagram of the present project


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Water tanks requirements

(for a gravity supply)


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A water storage cistern shall be fitted with:

Ball valve Gate valve at the inlet (a gravity supply only) An automatic controlswitch and without any stop valve in the case of a pumped supply. Gate valve atoutlet pipe . drain-off pipe properly plugged or with control valve (adequate means to prevent any unauthorized operation) Overflow pipe

Gate valve

Ball valve

Mechanical float switch


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Fittings used in plumbing


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QUESTIONS ????


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Chap. 3

Design recommendations & Calculations


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Fixture-Unit ComputationsComputing fixture units is a fundamental element of sizing piping systems for water distribution and drainage. Values assigned to specific types of fixtures arecrucial in the sizing of a plumbing system. There are two types of ratings forfixture units: a) The first deals with potable / domestic water units; b) and the second type has to do with the needs for drainage fixture systems. Both typesof ratings are needed when designing a plumbing system.


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Ref [8] providing you with sample tables of fixture-unit ratings. The tables arebased on actual code regulations, but always refer to your local code for exactstandards in your region. As you look over the tables that will follow, pay attention to all details. It is not unusual for code requirements to have exceptions. When an exception is present, the tables in code books are marked to indicatea reference to the exclusion, exception, or alternative options. You must be aware of these notes if you wish to work within the code requirements. Computing fixture units is not a complicated procedure and all you really need to know is how to read and understand the tables that will give you ratings for fixture units. Using fixture units to size plumbing systems is a standard procedure for manyengineers. The task is not particularly difficult.


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Drainage Fixture Units Pipes used to convey sanitary drainage are sized based ondrainage fixture units. It is necessary to know how many fixture units are assigned to various types of plumbing fixture units. This information can be obtained, in most cases, from local code books. Not all plumbing codes assign the same fixture-unit ratings to fixtures, so make sure that you are working with the assigned ratings for your region. Let me give you some sample tables to review WaterDistribution Fixture units Water distribution pipes are also sized by using assigned fixture-unit ratings. These ratings are different from drainage fixture units, but the concept is similar. As with drainage fixtures, water supply pipes can be sized by using tables that establish approved fixture-unit ratings. Most local codes provide tables of fixture-unit ratings.


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Daily Water Requirement1-Daily water requirement & Tanks capacities. ( two methods are used to determine the daily water requirement ,the first is base on the number of occupants , the second is based on the load value). 2- Load value (W.f.u.)


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Average Daily Water Requirement for StorageTable W-1Type of Establishment Gallons (per day per person) 15 25 35 15 35-50 50 100 Ref[2]

Schools (toilets & lavatories only) Schools (with above plus cafeteria) Schools(with above plus cafeteria plus showers) Day workers at schools and offices Residences Hotels (with connecting baths) Hotels (with private baths, 2 persons perroom)


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TYPE OF ESTABLISHMENT Schools (toilets & lavatories only) Schools( with above plus cafeteria) Schools (with above plus cafeteria plus showers) Day workers at schools and offices Day camps Trailer parks or tourist camp with built-in bath) builtTrailer parks or tourist camp with central bathhouse) Work or construction camp Public picnic parks toilet wastes only) Public picnic parks( bathhouse, showers , & flush toilet) Swimming pools and beaches Country clubs Luxury residencesand estates Rooming houses Boarding houses Hotels with connecting baths) Hotelswith private baths,2 persons per room) Boarding schools Factories gallons/person/shift, exclusive of industrial wastes) Nursing homes General hospitals Public institutions other than hospitals) Restaurants (toilet & kitchen wastes per unitof serving capacity) capacity)

GALLONS (per day per person) 15 25 35 15 25 50 35 50 5 10 10 25 per locker 150 40 50 50 100 100 25 75 150 100 25


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Daily Water Requirement for Storage ( Based on the number of occupants)Example calculation of daily domestic water requirement Suppose we have 24 floors & each floor consists of 4 flats, 2 of them having 3 bedrooms 2 of them having2 bedrooms. +1 Mad each flat. As a rule of thumb we take 2 persons/bed room. Total number/floor = 232+222+4 = 24 Persons/floor. Total number of occupants= 24 24 (labors+ concierges etc) = 581 Persons. From table W-1 the daily water requirement is between 35-50 gal/ day (Residential Building), The daily water requirementfor the whole building is: => 50581 = 29000 gallons /day 110 m3/day


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Capacity of Underground & Roof Tanks:Based on Plumbing code , the daily water requirement is divided between the roof& underground tanks as follows: 1 day's water requirement on the roof & 2 days on the ground floor ( standard ). As mentioned before the total amount of water needed for the 24 floors building is 110 m3 ,this equivalent to 110 tones additional weight on the roof. On the other hand 2 x 110 = 220 m3 must be stored in thebasement floor, this may affect the number of cars in the basement. As a general rules ( one day water storage on the roof & basement may be satisfactory ,if water flow from well pump is guarantied ).

N.B. Potable ( drinking+ cooking) water tank capacity is calculated based on 10-12 L / person / day


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Water storage for fire fightingFor buildings & in particular high rise buildings, it is reliable that, water for fire fighting is provided by gravity storage wherever possible. Using elevation as the means for developing proper water pressure in water mains risers & FHCs, not dependent on pumps that could fail or be shut down as a result of an electrical outage. Storage can be provided through one or more large storage reservoirs or by multiple smaller reservoirs throughout the community that are linked together .A reasonable rule of thumb is that water storage for fire fighting should be sufficient to provide at least one hour of water .For example, in a typicalresidential building with an ordinary hazards, the storage for fire flow of 100GPM for 30-60 min may be appropriate.


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Hose reel installation should be designed so that no part of the floor is more than 6 m from the nozzle when the hose is fully extended. The water supply must be able to provide a discharge of not less than 33 gpm through the nozzle and also designed to allow not less than three hose reels to be used simultaneously atthe total flow of 100 gpm for one hour duration. The minimum required water pressure at the nozzle is 2 bar where the maximum allowable pressure is 6.9 bar. Adequate system pressures is about 4.5 bars .Booster pump is used for top roof flats. The rubber hose reel length is 32 m & could be 1 or diameter (British standard), or 1.1/2(US standard), and the jet should have a horizontal distance of 8 m anda height of about 5 m.

For commercial building: Riser main pipe diameter D= 2.1/2 Branch pipe diameter=1.1/2 Rubber hose reel diameter = 1 .


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Siamese connection

Located next to fire escape


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Water storage for irrigation (Building area)Irrigation systems could be by hose or automatically using pump , electrical valves ,timers & sprinklers. As a rule of thumb ,the water consumption for irrigation is estimated as follows: The green area x 0.02 m /day For example : Suppose we have a 500 m2 green area to be irrigated. Calculate the water storage & the pumping rate per hour. 500 x 0.02 = 10 m3. & the pumping rate is 10 m3/h.


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Pipe sizingDetermine the number of FUs From Table W-1 Determine the probable flow rate gpm From Chart-1 or Table W-2 Determine the Pipe size Pipe flow Chart-2 N.B. Pipe material should be known in order to use the corresponding pipe flow chart.


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Determine the probable flow rate L/S at the inlet of each flat Based on French Standard norm NFP41 -201


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French Standard For Probable Water DemandStandard norm NFP41 -201

Cold Water Closet Lavatory Bathtub Shower Kitchen Sink Bidet 0.1 0.1 0.35 0.25 0.2 0.1

Hot (l/s) --0.1 0.35 0.25 0.2 0.1

Q = K . qii =1Q = Q1 + Q2 + Q3 + Q4

n

K=

1 x 1

0.2 K 1

K = Coefficient of simultaneous x = Number of units K = 1 ( case of Sport center)In our calculation , The American Standard will be applied National plumbing codeof USA


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Probable Water Demand F.U.s ( Cold + Hot )Table W-2Ref [2]Fixture Type Water closet - Flush tank Water closet - Flush valve Bidet Bath tubLavatory Lavatory Shower Shower Urinal - Flush tank Kitchen sink Restaurant sink Mop sink Drinking fountain Dish washer, washing mach. Use (Private) (Public) (Private) (Private) (Private) (Public) (Private) (Public) (Public) ----(Private)

Standard Plumbing Code of USA .F.Us 3 10 2 2 1 2 2 3 5 2 4 3 1/2 2 The value for separate hot and cold water demands should be taken as of the total value


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Table W-2 Ref [2]

Sizing the indoor cold Water pipe

The value for separate hot and cold water demands should be taken as of the


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SIMULTANEOUS DEMAND Probability of Use: (a) The probability that all the taps ina commercial building or a section of the piping system will be in use at the same moment is quite remote. If pipe sizes are calculated assuming remote that all taps are open simultaneously, the pipe diameters arrived at will be prohibitively large, economically unviable and unnecessary. (b) A 100% simultaneous draw-off may, however, occur if the water supply hours are severely restricted in the building. It also occurs in buildings, such as factory wash-rooms, hostel toilets, showers in sports facilities, places of worship and the like, In these , cases, all fixtures are likely to be open at the same time during entry, exit and recess. The pipe sizes must be determined for 100% demand.


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(c) In buildings with normal usage, the probability of simultaneous flow is based on statistical methods derived from the total number of draw-off points , average times between draw-offs on each occasion and the time interval between occasion of use . There is complex formula to get the probable water demand, howevera simple chart & table are used to determine the probable water demand which arepresented below in chart 1 & table W-3. Remark Chart 1 & Table W-3 cover both flash tank and Flash valve data.


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Ref [2]

For the whole bldg.

Water Hammer Arrestor

Chart -1

For each flat

Flush valve


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Table W-3

Ref [2]

Fixture Units equivalent to water flow in gpm


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Volume Flow Rate (Cold+Hot) at The Inlet of Flat.Pipe size at inlet of the flat is determined based on FUs. For example suppose itis require to determine the inlet flow rate (gpm) of an apartment having the following fixtures: 3 W.C( flash tank) + 2 bidet + 3 lavatory + 1 shower + 2 bathtube + 1 sink + 1 Dish washer. From table W-1 we get : (33 F.U + 22 F.U + 31 F.U +21 F.U +22 F.U + 12 F.U+ 12 F.U) 26 F.U From Graph-1 or table-2 we select the prole water demand for each identical flat : is 20 gpm ( 1.24 L/s).


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Volume Flow Rate (Cold+Hot) for the whole building. If four risers pipe are usedto supply water for the whole building The probable flow rate is determined asfollows: Assuming 24 floors each floor has 4 identical apartments As calculatedbefore the probable water demand for each apartment is 26 F.US , therefore 24 x 26 x 4 = 2496 F.US let say 2500 FUs. Inter Graph-1 with a value of 2500 FU and readthe corresponding probable water demand for whole building which is 380 gpm . Since we have four risers the total gpm is divided by 4 , that will be 95 gpm. Each riser will be sized based on this value i.e. 95 gpm. D=2.1/2 Without question the plumbing fixture in this blg.will not operate simultaneously , the diversity factor is included in Chart -1


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Sizing a Water supply systemThe most important design objective in sizing the water supply system is the satisfactory supply of potable water to all fixtures, at all times, and a proper pressure and flow rate for normal fixture operation. This may be achieved only ifadequate sizing of pipes are provided. The Main objectives in designing a watersupply system are: a) To achieve economical size of piping and eliminate over design. b) To avoid corrosion-erosion effects and potential pipe failure or leakage conditions owing to corrosive characteristic of the water. c) To eliminate water hammering damage and objectionable whistling noise effects in piping due to excess design velocities of flow .


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Sizing an upfeed water Pipe system. (Based on the city main water pressure).The local water department generally keeps records of the pressures in the mainsat different hours of the day and night. It is essential to know the water pressures before sizing the water piping for a building.


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Procedure to size an upfeed water distribution system 1- Decide what is the desirable minimum pressure that should be maintained at the highest fixture in the supply system. 2- Determine the elevation of the highest fixture or group of fixtures above the water (street) main. Multiply this difference in elevation by forty-three hundredths (0.43). The result is the loss in static pressure in psi (pounds per square inch) . 3- Subtract the sum of loss in static pressure (A ) andthe pressure to be maintained at the highest fixture (B), pressure loss in meter( D) from the average minimum daily vice pressure (E) . The result will be the available pressure to overcome friction loss in the supply pipes.


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4- Determine the total effective length ( TEL) of the pipe from the water streetmain to the highest fixture. If close estimates are desired, compute with the aid of Table () the equivalent length of pipe for all fittings in the line from the water (street) main to the highest fixture and add the sum to the developed length. 5- The pressure available for friction in pounds per square inch dividedby the effective lengths of pipe from the water (street main to the highest fixture, times one hundred (100), will be the average permissible friction loss perone hundred foot length of pipe. 6- Knowing the permissible friction loss per one hundred (100 feet of pipe and the total demand, the diameter of the building supply pipe may be obtained from pipe flow Charts .


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The following Items are first determined: Pressure lost due to height A operating fixture flow pressure B Pressure lost by friction in piping C Pressure lost byflow through meter D Street main pressure E In a design, items A, B, and E areknown. A is found in Table (8). Street main pressure, E, is a characteristic ofthe local water supply. Item B, is the pressure lost due to height, can be foundby multiplying the height in feet by 0.433 The value of item D is estimated. (For residences and small commercial buildings, it rarely exceeds 2 in fig ( )).


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Pressure loss in water meters


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ExampleAn upfeed system has following data . Calculation the unit friction loss per 100ft and size the pipe. Street main pressure (minimum) 50 Psi Height, topmost fixture above main 30 ft Total Fixture units in the system is 85 FUs. Topmost fixture type is a water closet with flush valve The pipe length (DL) 100 ft TEL = DL +50% (roughly estimation) TEL = actual length of the piping to the highest and most remote fixture (DL) + Pipe equivalent length of fittings (roughly is estimated as 50% of the DL).


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Solution : From the minimum street main pressure, subtract the sum of the fixture pressure, the static head, and the pressure lost in the meter. We get: A-fixture pressure (Table) 15 Psi B-static head 30 x 0.433 13 Psi D-pressure drop in Flow meter (estimated, 8 psi) 8 psi Total 36 Psi E Street pressure, (given) 50 PsiAvailable pressure = E- (A + B + D) = 50-36 = 14 Psi TEL = DL + 50% (roughly estimation) =100 ft +50 ft =150 ft. The unit friction loss per 100 ft becomes: 14Psi x 100/150 TEL = 9.33 psi/100 ft. For 85 Fus the corresponding flow rate is 64gpm. Now enter the pipe flow chart for rough iron pipe with 9.33 Psi/100 ft & 64 gpm. The intersection gives 2 inches. The corresponding flow velocity is 8 ft/s less than 10 ft/s (Okay).


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Sizing water Pipe systems for tall building(The city main water pressure is unsatisfactory)

Using water pumps


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Pipe sizingPipe flow charts are available which shows the relation between the water flow in gpm or L/s , pressure drop in Psi or ft / 100 ft , pipe diameter in mm or inches and the corresponding flow velocity in m/s or ft/s. The acceptable pressure drop per 100 ft is around 2-5 Psi/100ft ,that, in order to avoid excessive pressure loss and the need for higher pressure to maintain the flow rate. Low velocitypipe less than 0.5 m/s can cause precipitation of sand and others in the pipe .Pipe flow charts are available for different pipes material such as copper water tube, galvanized iron, & plastic pipes.


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Sizing based on Velocity limitationIn accordance with good engineering practice, it is recommended that maximum velocity in water supply piping to be limited to no more than 8 ft/sec (2.4m/sec),this is a deemed essential in order to avoid such objectionable effects as the production of whistling line sound noise, the occurrence of cavitation, and associated excessive noise in fittings and valves. It is recommended that maximum velocity be limited no more than 4ft/sec (1.2m/sec) in branch piping from mains, headers, and risers outlets at which supply is controlled by means of quick-closing devices such as an automatic flush valve, solenoid valve, or pneumatic valve,or quick closing valve or faucet of self closing, push-pull, or other similar type. This limitation is deemed necessary in order to avoid development of excessive and damaging shock pressures in piping equipment when flow is suddenly shut off. But any other kind of pipe branch supply to water closet (tank type) and non-quick closing valves is limited to 4 ft/sec(1.2 m/sec). Ref [2]


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Recommendation for minimizing cost of pumping Velocity limitation is generally advisable and recommended in the sizing of inlet and outlet piping for water supply pumps . Friction losses in such piping affect the cost of pumping and shouldbe reduced to a reasonable minimum .the general recommendation in this instanceis to limit velocity in both inlet and outlet piping for water supply pumps to no more than 4ft/sec (1.2 m/sec), this may also be applied for constant-pressurebooster-pump water supply system


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SIMPLIFIED STEP BY STEP PROCEDURE FOR SIZING PIPING ( Based on Velocity limitation) Ref [2] The procedure consists of the following steps: 1-Obtain the following information: (a) Design bases for sizing (b) Materials for system (c) Characteristics of the water supply (d) Location and size of water supply source (e) Developed length of system (straight length + equivalent length of fittings) (f) Pressure data relative to source of supply (g) Elevation (h) Minimum pressure required at highest water outlet 2-Provide a schematic elevation of the complete water supply system. Show all piping connection in proper sequence and all fixturesupplies. Identify all fixture and risers by means of appropriate letters numbers or combinations .Specially identify all piping conveying water at a temperature above 150F(66 C), ,and all branch piping to such water outlets as automatic flush valves, solenoid valves, quick-closing valves. Provide on the schematic elevation all the necessary information obtained as per step1


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3-Mark on the schematic elevation for each section of the complete system, the hot- and cold water loads conveyed thereby in terms of water supply fixture unitsin accordance with table (wsfu gpm). 4-mark on the schematic elevation adjacentto all fixture unit notations, the demand in gallons/min or liter/sec, corresponding to the various fixture unit loads in accordance with table (wsfu-gpm). 5-Mark on the schematic elevation for appropriate sections of the system, the demandin gallons /min or liter/sec for outlets at which demand is deemed continuous,such as outlets for watering gardens irrigating lawn ,air-conditioning apparatusrefrigeration machines, and other using continuously water. Add the continuousdemand to the demand for intermittently used fixtures and show the total demandat those sections where both types of demand occur 6-size all individual fixturesupply pipes to water outlets in accordance with the minimum sizes permitted byregulations. Minimum supply pipe size is given in table (1). 7-Size all parts of the water supply system in accordance with velocity limitation recognized as good engineering practice, with velocity limitation for proper basis of design, 2.4 m /sec for all piping, except 1.2 m /sec for branches to quick closing valves.


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1.35 m/s

V=2 m/s

D


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How to use the pipe flow-chart

The use of the pipe flow chart is best presented by an example : A fairly roughsteel pipe is used to deliver 20 gpm of water at ordinary temperature with a maximum allowed pressure drop of 5Psi/100 ft .What is the recommended pipe size that can be used ? Solution : Enter the Figure along the abscissa with the value of5 Psi/100 ft , move upward to the ordinate where QV is 20 gpm .From the intersection ; read the values of ( D )and the corresponding flow velocity ( V ) . Nowit is clear that the intersection lies between 1.1/4 and 1 diameter . If the 1 inpipe is used , the pressure drop will be 15 Psi/100 ft which is greater than thegiven value . This s is unacceptable. If the 1.1/4 pipe is used , the pressure drop will be 4 Psi/100 ft which is less than the maximum allowed pressure drop .Iwould recommend D=1.1/4 with a flow velocity less than 3 m/s. The flow velocityis about 1.35 m/s .


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Size of Principal Branches and Risers- The required size of branches and risers may be obtained in the same manner asthe building supply by obtaining the demand load on each branch or riser and using the permissible friction loss described before. - Fixture branches to the building supply, if they are sized for them same permissible friction loss per onehundred (100 feet) of pipe as the branches and risers to the highest level in the building, may lead to inadequate water supply to the upper floor of a building ( case of upfeed water supply) . This may be controlled by: (1) Selecting thesizes of pipe for the different branches so that the total friction loss in eachlower branch is approximately equal to the total loss in the riser, including both friction loss and loss in static Pressure;


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(2) throttling each such branch by means of a valve until the preceding balanceis obtained; (3) increasing the size of the building supply and risers above theminimum required to meet the maximum permissible friction loss. Refer to Upfeed& down feed system . - The size of branches and mains serving flush tanks shallbe consistent with sizing procedures for flush tank water closets.


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Avoid oversizing & undersizingOversizing

High cost extra but unnecessary

Delay in getting at outlets low flow velocity Increase heat loss from distributing piping

Undersizing

Slow or even no water during peak demand

Variation in pressure at outlet (obvious in mixer for shower) High noise level due to high flow velocity is expected.


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Sizing the riser diagramD6 ?Hot water

1.25 "

D1 ?

4 Pressure relief valve

Inlet water flow ?D2 ?

Electrical water heater Cold water 1" 1"

D3 ? D4 ?

D?

3/4 of the total fixture units are used for cold water

H.W.

D5 ?


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Equal friction loss

Open system


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Sizing the various pipes of the net work

3/4 of the total fixture units are used for cold water Bathtub WC Bidet LavatoryShower Sink

?" ?"

?" ?"

?" ?"

?" ?"

?" ?"

Determine the pipe sizes of the present drawing

H.W.


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Minimum size of fixture supply pipeThe diameters of fixture supply pipes should not be less than sizes in table below . The fixture supply pipe should terminate not more than 30 inch (0.762 m), from the point of connection to the fixture.Fixture Bathtub Drinking fountain Dishwashing machine Lavatory single head-Shower flushing rim-Shower flush tank-Urinal in flush valve1-Urinal flush valve-Watercloset flush tank-Water closet Minimum size of pipe " "3/8 " "3/8 " " " " "1 "


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Ref [2]


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General remarks on the installation of water pipes1- Every apartment should have a valve on the main cold water pipe feeding thisapartment. Every bathroom should have two valves one for cold and the second forhot water pipe. 2- Each plumbing Fixture should have and angle valve for maintenance reason. 3- Exposing pipes are installed approximately 3 cm from wall withhangers and supports. 4- Antirust paint is recommended for all expose steel pipes. 5- Pipe under tiles or in walls are PPR if however steel pipes are used , thepipe are wrapped with jute and asphalt . 6- Pipes crossing walls should be through pipe sleevesA rule of thumb is that not more than two fixture should be served by a single branch


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Pressure Requirements1- Pressure required during flow for different fixtures. 2- Pressure required atthe inlet of the flat. 3- The hydrostatic pressure available at each shutoff valve. 4- Pressure reducer valve PRV


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Pressure Required During Flow for Different Fixtures

N.P.Code USA

Ref [8]


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Pressure Required At The Inlet Of each FlatAs it well known the Hydrostatic pressure @ shut-off valve is given by :The maximum pressure at the inlet of the flat is Limited to 30 m which is about2.9 bar , that , avoid excessive pressures

Where is the specific weight kN/m3 & h is the pressure head in m

P = h

If the pressure is more than 2.9 Bar :You may need break-pressure tank or pressure reducing valve. The available pressure at the inlet of the flat, has to overcome the pressure loss due to pipe friction and fittings of the longest branch and have a surplus pressure to operatesthe most critical fixture ( for example Dish washer or shower). Pressure Drop, P= x hL + Surplus pressure ( hL is the head loss due to pipe friction ) Allowingadditional pressure drop around 25-30% for fittings on straight pipe or calculate the effective length for minor losses as described in Fluid Mechanics Lecturenotes. It is always recommended to use the K value for the calculation of the pressure drop.


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Example of high riser Building24 floors

Ref [4]


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The hydrostatic pressure available at each shut-off valve.


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R 1E CT FL TV V LE RIC OA AL E BL CK O -B UPPE D M ICW TE TA K R O EST A R N 2 * 10000 litres ( P.ET K AN S) 3" 4" F.F.P

R 2BL C B OK2 1/2" FR MD .P-B O .W

R 3EL TR FLO V V EC IC AT AL E

R 4BL CK O -B U RDO E PPE M STICW T T NK A ER A 2 * 10000 litres ( P.ET N A KS) 3"4" F.F.P

4" C.W .P 3" C.W .P

4" C .P .W 3" C .P .W

U PPERRO F O

RO F O1 1/4" C.W .P 3" C.W .P 3" C.W .P 1" C.W .P 3" C.W .P 3" C.W .P 4" C.W .P 1" C.W.P 3" C.W .P 1 1/4" C.W .P 3" C .P .W

F.F.P

F.F.P

24T . FL O H OR1" C.W .P 1" C.W .P 3" C.W .P 1" C.W .P 3" C.W .P 1" C.W .P 3" C .P .W

Riser diagram ( pressure reducers)

3" C.W .P

23RD FLO R . O

1" C.W .P 3" C.W .P 1" C.W .P 3" C.W .P 1" C.W .P 3" C.W .P 1" C.W .P 3" C .P .W

22N . FLO R D O1" C.W .P 3" C.W .P 1" C.W .P 3" C.W .P 1" C.W .P 3" C.W .P 1" C.W .P

21ST. FL O OR1" C.W .P 3" C.W .P 1" C.W .P 2 1/2" C.W .P 1" C.W .P 2 1/2" C .P .W 1" C.W .P 3" C .P .W

20T . FL O H OR1" C.W .P 3" C.W .P 3/4" C .P .W 2 1/2" C.W .P 3/4" C .P .W 2 1/2" C .P .W 3/4"C.W .P 3" C .P .W

19T . FL O H OR1" C.W .P 3" C.W .P 3/4" C .P .W 2 1/2" C.W .P 3/4" C .P .W 3/4" C.W .P

D.W.P.L

2 1/2" C .P .W

3" C .P .W

18T . FL O H OR


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1" C.W .P 3/4" C .P .W 2 1/2" P.R .V 3" P.R.V 2 1/2" P.R .V 3/4" C .P .W 3/4" C.W .P 3" P.R .V

17T . FL O H OR1" C.W .P 3" C.W .P 1" C.W .P 2 1/2" C.W .P 1" C.W .P 2 1/2" C .P .W 1" C.W .P 3" C .P .W

16T . FL O H OR1" C.W .P 2 1/2" C.W .P 1" C.W .P 2 1/2" C.W .P 1" C.W .P 2 1/2" C .P .W 1" C.W.P 2 1/2" C .P .W

15T . FL O H OR1" C.W .P 2 1/2" C.W .P 1" C.W .P 2" C.W .P 1" C.W .P 2" C.W .P GLO VA (T P. ) BE LVE Y 1" C.W .P 2 1/2" C .P .W

14T . FL O H OR2 1/2" 1" C.W .P 2 1/2" C .P .W

1" C.W .P 2 1/2" C.W .P

1" C.W .P 2" C.W .P

1" C.W .P 2" C.W .P

13T . FL O H OR1" C.W .P 2 1/2" C.W .P 3/4" C .P .W 2" C.W .P 3/4" C.W .P 2" C.W .P 3/4" C.W .P2 1/2" C .P .W

12T . FL O H OR1" C.W .P 2" C.W .P GLO VA (T P. ) BE LVE Y 3/4" C .P .W 2" C.W .P 3/4" C.W .P 2" C.W .P 3/4" C.W .P 2" C .P .W G EV E( T P. ) LOB ALV Y

11T . FL O H OR3/4" C .P .W 2" P.R .V 3/4" C.W .P 3/4" C.W .P 2" P.R .V 2" P.R .V

1" C.W .P

2" P.R.V

10T . FL O H OR1" C.W .P 2" C.W .P 1" C.W .P 2" C.W .P GL EVA E( T P. ) OB LV Y 1" C.W .P 2" C.W .P 1" C.W .P

D.W.P.L

2" C .P .W

9T FLO R H. O1" C.W .P 1 1/2" C.W .P GLO VA (T P. ) BE LVE Y 1" C.W .P 2" C .P .W

1" C.W .P 2" C.W .P

1" C.W .P 1 1/2" C.W .P

8T FLO R H. O1" C.W .P 2" C .P .W

1" C.W .P 2" C.W .P

1" C.W .P 1 1/2" C.W .P


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1" C.W .P 1 1/2" C.W .P

7T FLO R H. O1" C.W .P 1 1/2" C.W .P 1" C.W .P 1 1/2" C.W .P 1" C.W .P 1 1/2" C.W .P 1" C.W .P 1 1/2" C .P .W

6T FLO R H. O1" C.W .P 1 1/2" C.W .P 3/4" C .P .W 1 1/4" C.W .P 3/4" C.W .P 1 1/4" C.W .P 3/4" C.W .P 1 1/2" C .P .W

5T FLO R H. O1" C.W .P 3/4" C .P .W 3/4" C.W .P 3/4" C.W .P

1 1/2" C.W .P

1 1/4" C.W .P

1 1/4" C.W .P

1 1/2" C .P .W

4T FLO R H. O1" C.W .P 3/4" C .P .W 1 1/4" P.R .V 1 1/2" P.R.V 1 1/4" P.R .V 3/4" C.W .P 3/4"

C.W .P 1 1/2" P.R .V

3RD FLO R . O1" C.W .P 1" C.W .P 1" C.W .P 1" C.W .P

1 1/4" C .P .W

1" C.W .P

1" C.W .P

1 1/4" C .P .W

2N . FLO R D O1" C.W .P 1" C.W .P 1" C.W .P 1" C.W .P

1 1/4" C.W .P

D.W.P.L

1 1/4" C .P .W

1ST. FLO R O3/4" C .P .W 2 1/2" D EST W TE PU PIN L E OM IC A R M G IN 1" G.S.P 1" G N LSERICEPIPE E ERA V 1" 3/4" C .P .W

G . FL O RD O R3/4" G .S.P 3/4" G.S.P

3/4" G .S.P 1 1/4" W LW TE PIPE EL A R

3/4" G.S.P

3/4" G .S.P

3/4" G.S.P


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F.H .C PO B W TE IN OM PIPE TA LE A R C ING BL K L W D E ICW ERT N OC -B O ER OMST AT A K 8 * 4000 litres (P.ET NK A S) &4 *3000litres (P.ET K AN S) 3" 3" D.W.P.L D M STICW T PUM O E A ER PINGSTA TIOND .P-B .W 20m @95 mE C 3/HR AH

Indirect pum system ping

Ref [4]


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1" C .P .W 11/2" C .P .W FLO TV LV A A E

1" C .P .W 11/4" C .P .W

M H O M2 EC .R OU PPERD M O ESTICW TERTA K A N 3*10000litres ( P.ETA K N S)

1" C .P .W

1" C .P .W 11/2" C .P .W

11/4" C .P .W

FLO TV LV A A E p.r D pipe rain 1" C .P .W

19TH FLO R . O

1" C .P .W 11/4" C .P .W 3"

p.r

11/4" C .P .W 3"

3"

18TH FLO R . O1" C .P .W 11/2" C .P .W

1" C .P .W

1" C .P .W 11/2" C .P .W 3" C .P .W

1" C .P .W

11/2" C .P .W

11/2" C .P .W

17TH FLO R . O11/4" C .P .W

11/4" C .P .W

11/4" C .P .W

11/4" C .P .W

16TH FLO R . O11/4" C .P .W 11/4" C .P .W 11/4" C .P .W 11/4" C .P .W

15TH FLO R . O


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R1ELECTRICFLO TV L E A AV BLO -B CK U PPERD M O ESTICW T TA K A ER N 2* 7500litres( P.ET N S) AK 3"

R2BLO B CK2 "FRO D .P-B M .W

R3ELECTRICFLO TV LV A A E

R4BLO -B CK U PPERD M O ESTICW T TA K A ER N 2* 7500litres ( P.ET N S) AK

M .RO M1 ECH O4"C.W .P 4"C.W .P

3"

4" F.F.P

BO STERU IT(TY R1 - R4) O N P PU PS- 9m R@15mH D M 3/H EA O ESTA DBYW PRE R TA K200L N N ITH SSU E N

U PPERRO F O3"C.W .P

3"C.W .P

RO OF11/2" C.W .P 1 1/4" C.W .P 1 1/2" C .P .W 1 1/4" C .P .W 3"C.W .P 1 1/2" C .P .W1 1/4" C .P .W 1 1/2"C.W .P 1 1/4"C.W .P

Riser diagram (Break pressure tanks II)

BO STERU IT(TY R2 - R O N P 3) PU PS- 6.8m R@15mH D M 3/H EA O ESTA DBYW PRES RETA K200L N N ITH SU N

24TH FLO R . O

11/4" C.W .P 2"C.W .P 2"C.W .P

1 1/4" C .P .W

1 1/4" C.W .P2"C.W .P

1 1/4"C.W .P 2" C.W .P

23RD FLO R . O

11/4" C .P .W 2"C.W .P 11/4" C .P .W 2"C.W .P 1 1/4" C.W .P 2" 2"C.W .P 2"C.W .P1 1/4" C.W .P

22N . FLO R D O11/4" C .P .W 2"C.W .P 11/4" C .P .W 1 1/2"C.W .P 1 1/4" C.W .P 1 1/2"C.W .P 1 1/4" C.W .P

2"C.W .P

21ST. FLO R O


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11/4" C .P .W 2"C.W .P 11/4" C .P .W 1 1/2"C.W .P 1 1/4" C.W .P 1 1/2"C.W .P 1 1/4" C.W .P 2"C.W .P

20TH FLO R . O11/4" C .P .W 11/2" C.W .P 11/4" C .P .W 11/4" C .P .W 1 1/4" C.W .P 1 1/4" C.W.P 1 1/4" C.W .P 1 1/2" C.W .P

ELEC TRICFLOA VA E T LV

M .RO M2 ECH O

Delay float -valve

19TH FLO R . O1 1/4" C.W .P 1 1/4" C.W .P

11/4" C .P .W 11/4" C .P .W

U PPERDO ESTICW TERTA M A NK 4 * 10000 litres ( P.ETA K N S)

3"

D pipe rain

3" 3"

18TH FLO R . O1 1/4" C.W .P 1 1/2" C.W .P

11/4" C .P .W

11/4" C .P .W 1 1/2" C.W .P 3"C.W .P

1 1/4" C.W .P

1 1/2"C.W .P

1 1/2"C.W .P

17TH FLO R . O1 1/4" C.W .P

1 1/4"C.W .P

11/4" C.W .P

11/4" C.W .P

16TH FLO R . O11/4" C.W .P 1 1/4"C.W .P 11/4" C.W .P 1 1/4" C.W .P

15TH FLO R . O11/4" C.W .P 1 1/4"C.W .P 2"C.W .P 11/4" C.W .P 2" C.W .P G BE V LV ( T P. ) LOA E Y 1 1/4" C.W .P 2 "C.W .P

2" C.W .P

14TH FLO R . O2 1/2" 1 1/4" C.W .P 2 "C.W .P


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11/4" C.W .P 2" C.W .P

1 1/4"C.W .P 2"C.W .P

11/4" C.W .P 2" C.W .P

13TH FLO R . O11/4" C.W .P 2" C.W .P 1 1/4"C.W .P 1 1/2"C.W .P G BE V LV ( T P. ) LO A E Y 11/4" C.W .P 1 1/2"C.W .P 1 1/4" C.W .P 2 "C.W .P

12TH FLO R . O11/4" C.W .P 11/4" C.W .P 1 1/4" C.W .P 1 1/2" C.W .P G BEV LV ( TY ) LO A E P.

11/4" C.W .P 11/2" C.W .P G BE V LV ( T P. ) LO A E Y 11/4" C.W .P

1 1/4"C.W .P 1 1/4"C.W .P

M .RO M3 ECH O

D -Float V elay alve

11TH FLO R . O1 1/4" C.W .P

U PPERD M ICW TERT K O EST A AN 3 * 10000 litres ( P.ETA KS) N

3" 3" 3"

10TH FLO R . O1 1/4" C.W .P

11/4" C.W .P

11/4" C.W .P

11/4" C.W .P

1 1/2" C.W .P

1 1/2"C.W .P

11/2" C.W .P

D.W.P.L

1 1/2" C.W .P

9TH FLO R . O1 1/4"C.W .P 11/4" C.W .P 11/4" C.W .P 1 1/4" C.W .P

8TH FLO R . O1 1/4" C.W .P 1 1/4"C.W .P 1 1/4" C.W .P 1 1/4"C.W .P

7TH FLO R . O1 1/4" C.W .P 2"C.W .P 1 1/4"C.W .P 1 1/4" C.W .P 1 1/4"C.W .P 2"C.W .P

2"C.W .P

2"C.W .P


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6TH FLO R . O1 1/4" C.W .P 2" C.W .P 1 1/4"C.W .P 2"C.W .P 1 1/4" C.W .P 2"C.W .P 1 1/4"C.W .P 2"C.W .P


2"C.W .P

11/2" C .P .W

1 1/2"C.W .P

2"C.W .P


2" C.W .P

11/2" C .P .W

1 1/2"C.W .P

2"C.W .P

3RD FLO R . O1 1/4" C.W .P 1 1/4"C.W .P 1 1/4" C.W .P 1 1/4"C.W .P

2" C.W .P

11/4" C .P .W

1 1/4"C.W .P

2"C.W .P

2N . FLO R D O1 1/4" C.W .P 1 1/4"C.W .P 1 1/4" C.W .P 1 1/4"C.W .P

D.W.P.L

2" C.W .P

2"C.W .P

1ST. FLO R O3/4" C .P .W 2" C.W .P 11/4" C.W .P 2 1/2" D M O ESTICW TERPU PIN LIN A M G E 11/2" G ERA SERV PIPE EN L ICE 11/2" C.W .P 1"C.W .P

1 1/2" C.W .P

G D FLO R R. O1 1/4" G .S.P

1 1/4"G .S.P

1 1/4"G .S.P

1 1/4" G .S.P


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1 1/4"G .S.P 1 1/4" W W TERPIPE ELL A PO BLEW TERFRO M INCIT TA A M A Y

1 1/4" G .S.P

BLO -BLO ERD M CK W O ESTICW TE TA K A R N

3"

3"

DM O ESTICW TERPU PIN ST T ND .P-B A M G A IO .W 20 m R@95 mE C 3/H AH D P-pum p

Indirect pum systemCase study(II) ping

Ref [4]


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PRV


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Pressure Reducer Valve PRV


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The head loss due to pipe friction & fittingsReview your lecture notes .Ref [5] Chap.9-10 Or refer to [10]


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Now !! After completing the above chapters you should be able to : 1- Calculatethe daily water requirement for the given project & the capacity of the overhead& underground tanks. 2- Recognize the drawing of water distribution system inside the flat. 3- Selecting the type of the riser diagram i.e. Direct or indirectwater supply. Sizing the riser diagram. Sizing the pipes inside the bathrooms etc.. 4- Justified if the hydrostatic pressure at the inlet of the flat is enoughto overcome losses + the surplus pressure to operates the most critical fixture. 5- Do we need a booster pump for top roof? 6-Do we need a break -pressure tankor pressure reducing valve ?

Now move on to the next part Pump selection


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Design of pumping supply system to a buildingIn engineering practice, the process of pipe sizing and component selection is an iterative one , requiring the design engineer to first assume initial values :( the velocity , pressure and allowable pressure loss ) and recalculate if necessary using new values if the initial assumption was proved wrong . The pipe sizing is estimated easily using the pipe flow charts followed by a simple calculation to determine the pumps power. Usually, the equal friction loss method is thesimplest method used which gives acceptable results.


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The following procedure is used when estimating the pipe size and pumps duty ( based on equal friction loss rate )1) Prepare the drawing of the piping /pumping system, measure the length of thepipe connecting the underground tank to the overhead ( delivery ) tank and countall fittings along the way . 2) Find the required volume flow rate for each flat. Then, add them up to obtain the total flow rate at the peak demand The probable water demand for each flat is determined based on the number of occupants orbased on the total fixture units. ( It is not always easy to know the number ofoccupants in the early stage , so the second method using the T.F.Us becomes more reliable ) . 3) Since the equal friction loss method is used , choose a valueof friction loss rate for the main riser pipe based on the following limits : a) The recommended friction loss rate is between length or (2 -5 Psi per 100 ft ). b ) The velocity in the main should not exceed 1.2-1.8 m / s ( say 1.5 m/s ) in small systems , or 2.4- 3 m / s in larger systems . The velocity in occupied areas should not exceed 2.4 m/s, so as to prevent noise.


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Design of pumping supply system to a building ( cont)4) Select a pipe size from the pipe flowcharts based on the above limits . We could also prepare tables which present the pipe diameters , friction factor and flow rate . The tables are regarded as more accurate but the pipe flowcharts aremore convenient. 5) Continuing along the circuit chosen , select the succeedingpipe sizes . This should be done according to the following guides: Determine byinspection which branch will be the longest, or have the greatest equivalent length . Calculate the pressure drop in the longest circuit.


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Design of pumping supply system to a building ( cont)6 Calculate : a) The total effective length E.L which is: The actual pipe length+ Equivalent length (due to fittings and valves etc.). b) The total head loss or pressure drop hL is : The head loss per unit of length is about (5 ft w./100 ft ) multiplied by the effective length .

L eff . = L + L e

hL = h1 L eff .


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Design of pumping supply system to a building ( cont)7) The approximated pump s power is then calculated as follows : The head delivered by the pump or the total head of the pump: which is equal to the static head+ the total head loss ( case of open tanks ).

hA = hs t + hL

The theoretical power requirement (Water power) is P = x hAx QV . (Where is the specific weight of water, hA is the pump head in m and QV is the operating discharge m3/s ). The operating discharge is taken from the intersection of the pump characteristic curve with the pipe system curve.


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Safety MarginTo avoid any miscalculation during pump selection, it is recommended to apply asafety margin of around 5% for the estimated flow rate & 10 % for the estimatedhead. For example : Estimated Flow rate Q The recommended flow Q= 30L/s

= 30 L/s & & head will +5% , & H

Head 25 m be : =25m +10%


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Design of pumping supply system to a building ( cont)8 The shaft power of the pump can be determined by dividing water power by thepump efficiency. h Q

Pump Power =

The motor power of the pump can be determined by dividing water power by the overall pump efficiency.

A

V

hA QV Pump Motor Power = 0


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Hall, F., 1994. Building Services and Equipment, 3rd ed., Vol. 1 ,2 ,3 & 4 Moss,K. J., 1996. Heating and Water Mechanical & electrical equipment for buildings by Stein/Reynolds, Ninth edition, John Wiley, 2000. Practical Plumbing Engineering, Cyril M.Harris, ASPE,1998. Upland engineering, Mechanical consulting office,Dr. Ali Hammoud.

Services Design in Buildings.


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QUESTIONS ????


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