Page 1 :
Part I, , 1, , Plumbing Systems, , 1, , Lecture Notes, By Dr. Ali Hammoud, B.A.U-2005, , 1
Page 2 :
1, , 2, , Mechanical Engineering short-course, This course is prepared for 3 rd 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 14 hours, 7 hours for cold & hot water distribution systems in building., 7 hours for sanitary systems in building., By Dr. Ali Hammoud, Associate professor in fluid mechanics, & hydraulic machines, , 2
Page 3 :
1, , 3, , 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 to install 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, , 3
Page 4 :
1, 4, DRAINAGE AND SEWERAGE, SYSTEM, a- Safe Drainage System, All sanitary drainage systems should be connected to the, public sewer system (wherever available) at the nearest, possible point. In case the public sewer system is not available,, a safe and nonpolluting drainage system must be ensured. The, drainage system should be so designed as to guard against, fouling, deposit of solids and clogging., b- Vent Pipes, The drainage system should be designed to allow for adequate, circulation of air within the system, thereby preventing the, danger of siphonage or unsealing of trap seals under normal, working conditions. The system should have access to, atmospheric pressure and venting of foul gases by vent pipes., c- Exclusion of Foreign Substances from the System, d- Ground and Surface Water Protection, e- Prevention of Contamination, f- Prevention of Sewage Flooding, , 4
Page 5 :
Table of Contents part 1, Symbol & legend, Description of Architecture, drawings of the project, , • Design of Risers, • Daily W. Requirement, • Load Values W.F.U., , Cold water distribution system, “Calculation”, Calculation”, Hot water distribution system, “Calculation”, Calculation”, Dr. Hammoud, , Drawing of water distribution, inside the flats, Questions, 1, , • Pipe sizing, • Types of pumps, • Circulating Pump, • Pipe sizing, • Electrical W. heater, • Water storage heater, • Instantaneous or, semi-inst. heaters, 5, , 5
Page 6 :
Symbols & legends, SS, , SOIL STACK, , WS, , WASTE STACK, , VS, , VENT STACK, , V, , VENT, , SV, , STACK VENT, , RW, , RAIN WATER, , RWS, , RAIN WATER STACK, , CW, , COLD WATER, , SW, , SOFT COLD WATER, , PW, , POTABLE WATER, , HW, , DOMESTIC HOT WATER, , HWR, TS, WTR, , DOMESTIC HOT WATER RETURN, TANK SUPPLY, WATER, , DR, , DRAINAGE, , F.F, , FIRE FIGHTING, , G, , GAS, , A, , COMPRESSED AIR, , V, , VACUUM, , FOS, , 1, , FUEL OIL SUPPLY, , 6, , 6
Page 7 :
CI, , CAST IRON PIPE, , GS, , GALVANIZED STEEL PIPE ( SEAMLESS & WELDED ), , BS, , BLACK STEEL PIPE ( SEAMLESS ), , PVC, , POLYVINYLCHLORIDE PIPE, , C-PVC, , CHLORINATED POLYVINYLCHLORIDE PIPE, , PVC-U, , UNPLASTICIZED POLYVINYLCHLORIDE PIPE, , P.P, , POLYPROPYLENE PIPE ( DRAINAGE ), , P.P.R, , POLYPROPYLENE RANDOM PIPE ( WATER ), , PE-X, , CROSS-LINKED POLYETHYLENE PIPE, , PE-X / AL / PE-X, , PE-X , ALUMINUM , PE-X ( TRIPLE LAYER ) PIPE, , CU, , COPPER PIPE, , P.E, , POLYETHYLENE PIPE, , H.D.P.E, , AWC, EWC, B, LAV, S, SH, , HIGH DENSITY POLYETHYLENE PIPE, , ASIATIC WATER CLOSET, EUROPEAN WATER CLOSET, BIDET, LAVATORY, SINK, SHOWER, , KS, , KITCHEN SINK, , BT, , BATHTUB, , DF, , DRINKING FOUNTAIN, , HB, , HOSE BIB, , FT, , FLASH TANK, , FV, , FLASH VALVE, , 1, , 7, , 7
Page 9 :
1, , 9, , 9
Page 10 :
PLUMBING FIXTURES, , 1, , 10, , 10
Page 11 :
Project description, The project consist of two blocks A and Band a common Ground floor, 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, is about 700 m2., Each flat consist of one master bedroom, three bedrooms, one living, living room, one dining room,, one kitchen , maid room and six bathrooms., Floor to floor height is 3m, Water supply from 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., insufficient., (a) Work out daily water requirement, underground and overhead tank capacity, (b) Assuming indirect water supply system .Calculate the size of the, 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, flat as indicated in the, typical floor drawing. .Calculate the pipe diameters and branch, ch, lines, for these risers., bran, (d) Design the cold and hot water distribution system inside the flat., (e) size the pressure vessel of the top floors and the corresponding, corresponding pump duty., 1, , 11, , 11
Page 12 :
Block A 18 floors, , Block B 17 floors, , Refer to your drawing & follow the lecture, 1, , Typical floor 12, , 12
Page 14 :
Cars, , 1, , Ground floor, , 14, , 14
Page 15 :
Water, storage tanks, , 1, , Basement floor 15, , 15
Page 16 :
HOW TO READ AND DRAW THE, WATER DISTRIBUTION SYSTEM, INSIDE THE FLAT ., , 1, , 16, , 16
Page 17 :
Example of some pipe, accessories needed for water, distribution system, 1, , 17, , 17
Page 18 :
EXAMPLE OF WATER DISTRIBUTION SYSTEM INSIDE, BATHROOM – GALV. STEEL PIPES, , 1, , 18, , 18
Page 19 :
1, , 19, , 19
Page 20 :
DETAIL OF WATER DISTRIBUTION SYSTEM INSIDE, BATHROOM – P.P.R PIPES, , 1, , 20, , 20
Page 21 :
DETAIL OF WATER DISTRIBUTION SYSTEM INSIDE, BATHROOM – PEX OR PEX –AL-PEX PIPES, , 1, , 21, , 21
Page 22 :
Solution of a ,b & c, , Schematic water risers diagram for Madam Cury project, , 1, , 22, , 22
Page 23 :
Madam Cury project – water distribution system, E.W., for typical floor, , Heater, 1, , Solution of (d) Two Electrical water, heaters & two water risers, Electrical, W., Heater 2, , 1, , 23, , 23
Page 24 :
Madam Cury project – water distribution system, for typical floor, Another version, , Solution of (d), , with single large, Single Water, heater+ boiler, , 1, , 24, , 24
Page 25 :
1, , 25, , 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 “., , 25
Page 26 :
Chap.2, , 1, , 26, , Cold & Hot water, distribution systems, , 26
Page 27 :
Calculation Of, W.D. Systems, Design Of W.D., Systems, , Daily Water requirement, Load Values, Pressure requirement, , Pipe sizing, , 1© Max, Zornada (2002), Pump, selection, , 27, Slide 27, , 27
Page 28 :
Water Distribution Systems Up to 10 floors Bldg, , Indirect, , Direct, , 1, , 28, , 28
Page 29 :
Distribution Systems, Buildings above 20 floors, , Pressure vessel, , Pressure Reducer, , Break- pressure ( Branch water supply ), , Break -Pressure reservoires, , Direct supply ( Booster ), or frequency inverter, , Direct, , Indirect, 1, , 29, , 29
Page 30 :
1, , 30, , Multi-pipes system is always preferable, , Muli-pipes system, , Underground Tank, , Each flat has its own inlet flow pipe, , 30
Page 31 :
1, , 31, , Water storage in buildings, , Domestic, & Potable, , Fire fighting, , Irrigation, , 31
Page 32 :
1, , 32, , Domestic water storage in buildings, , Underground tanks, , Roof tanks, , 32
Page 33 :
1, , 33, , Storage of water, Water 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., , 33
Page 34 :
1, , 34, , Underground water storage Pumps –, Tanks Connections, , 34
Page 35 :
1, , 35, , Roof Tanks, Roof 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., tanks, , 35
Page 36 :
1, , 36, , Concrete Roof tanks, , 36
Page 37 :
1, , 37, , Galvanized Roof tanks, , Ref [4], , 37
Page 38 :
1, , 38, , P.P.R. Roof tanks, , 38
Page 39 :
Riser diagram, , 1, , 39, , 39
Page 40 :
1, Riser diagram of the, present project40, , 40
Page 41 :
Chap. 3, , 1, , 41, , Design recommendations, &, Calculations, , 41
Page 42 :
1, , 42, , Fixture-Unit Computations, Computing fixture units is a fundamental element, of sizing piping systems for water distribution, and drainage. Values assigned to specific types, of fixtures are crucial in the sizing of a, plumbing system. There are two types of ratings, for fixture units:, a) The first deals with drainage fixture units;, b) and the second type has to do with the needs, for potable / domestic water systems. Both, types of ratings are needed when designing a, plumbing system., , 42
Page 43 :
1, , 43, , Ref [8] providing you with sample tables of fixture-unit, ratings. The tables are based on actual code regulations, but, always refer to your local code for exact standards 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 indicate a, 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 many engineers. The task is not particularly, difficult., , 43
Page 44 :
Drainage Fixture Units, , 1, , 44, , Pipes used to convey sanitary drainage are sized based on, drainage 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, Water Distribution 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., , 44
Page 45 :
1, , 45, , Daily Water Requirement, 1-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.), , 45
Page 46 :
1, , 46, , Average Daily Water Requirement for Storage, Table WW-1, Type of Establishment, , Ref [2], Gallons, (per day per person), , Schools (toilets & lavatories only), , 15, , Schools (with above plus cafeteria), , 25, , Schools (with above plus cafeteria plus, showers), Day workers at schools and offices, , 35, , Residences, , 15, 3535-50, , Hotels (with connecting baths), , 50, , Hotels (with private baths, 2 persons per, room), , 100, , 46
Page 47 :
1, , Daily Water Requirement for Storage, ( Based on the number of occupants), , 47, , 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 having 2 bedrooms., +1 Mad each flat., As a rule of thumb we take 2 persons/bed room., Total number/floor = 2×3×2+2×2×2+4 = 24 Persons/floor., Total number of occupants= 24× 24 + 5 (labors+ concierges, etc…) = 581 Persons., From table W-1 the daily water requirement is between 35-50, gal/ day (Residential Building),, The daily water requirement for the whole building is:, => 50×581 = 29000 gallons /day ≈ 110 m3/day, , 47
Page 48 :
1, , 48, , 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 day’s 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 the basement 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, calculated based on, 1010-12 L / person / day, , 48
Page 49 :
1, , Water storage for fire fighting, z, , 49, , For 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 .For example, in a typical residential, building with an ordinary hazards, the storage for fire, flow of 100 GPM for 30-60 min may be appropriate., , 49
Page 50 :
1, 50, 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 at the 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 ¾” diameter, (British standard), or 1.1/2”(US standard), and the jet should have, a horizontal distance of 8 m and a 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” ., , 50
Page 51 :
1, , 51, , 51
Page 52 :
1, , 52, , Siamese connection, , Located next to fire escape, , 52
Page 53 :
1, , 53, , Water storage for irrigation, zIrrigation, , systems could be by hose or automatically, using pump , electrical valves ,timers & sprinklers., zAs 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., , 53
Page 54 :
1, , 54, , Pipe sizing, Determine the number of FU’s, 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., , 54
Page 55 :
1, , 55, , Probable Water Demand F.U.’s ( Cold + Hot ), Table W-2, Ref [2], , Standard Plumbing Code of USA, ., Fixture Type, , Use, , F.Us, , Water closet - Flush tank, , (Private), , 3, , Water closet - Flush valve, , (Public), Public), , 10, , Bidet, , (Private), , 2, , Bath tub, , (Private), , 2, , Lavatory, Lavatory, , (Private), , 1, , (Public), Public), , 2, , Shower, Shower, , (Private), , 2, , (Public), Public), , 3, , Urinal - Flush tank, , (Public), Public), , 5, , Kitchen sink, , --, , 2, , Restaurant sink, , --, , 4, , Mop sink, , --, , 3, , Drinking fountain, , --, , 1/2, , Dish washer, washing mach., , (Private), , The value for separate, hot and cold water, demands should be, taken as ¾ of the total, value, , 2, , 55
Page 56 :
Table W-2, Ref [2], , 1, , 56, , Sizing the, indoor cold, Water pipe, , The value for separate, hot and cold water, demands should be, taken as ¾ of the, t t l l, , 56
Page 57 :
1, SIMULTANEOUS, DEMAND, , 57, , Probability of Use:, (a) The probability that all the taps in a commercial building or, a section of the piping system will be in use at the same, moment is quite remote., remote If pipe sizes are calculated assuming, 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., , 57
Page 58 :
1, , 58, , (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, however a simple chart & table are used to, determine the probable water demand which are presented, below in chart 1 & table W-3., Remark Chart 1 & Table W-3 cover both flash tank and Flash, valve data., , 58
Page 59 :
Ref [2], , For the, whole bldg., , 1, , 59, , Water Hammer Arrestor, , Chart -1, , For each flat, , Flush valve, , 59
Page 60 :
Table W-3, , Ref [2], , 1, Fixture Units equivalent, to water flow in gpm, , 60, , 60
Page 61 :
1, , 61, , Volume Flow Rate (Cold+Hot) at The Inlet of Flat., Pipe size at inlet of the flat is determined based on, FU’s. For example suppose it is 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 bath tube + 1 sink + 1 Dish washer., From table W-1 we get :, (3×3 F.U + 2×2 F.U + 3×1 F.U + 2×1 F.U +2×2 F.U +, 1×2 F.U+ 1×2 F.U) ≅ 26 F.U, From Graph-1 or table-2 we select the probable water, demand for each identical flat : is 20 gpm ( 1.24, L/s)., , 61
Page 62 :
1, , 62, , Volume Flow Rate (Cold+Hot) for the whole building., If two risers pipe are used to supply water for the whole, building The probable flow rate is determined as, , follows:, , Assuming 24 floors each floor has 4 identical apartments, As calculated before the probable water demand for each, apartment is 26 F.U’S , therefore 24 x 26 x 4 = 2496, F.U’S let say 2500 FU’s., Inter Graph-1 with a value of 2500 FU and read the, corresponding probable water demand for whole building, which is ≅ 3000 gpm . Since we have four risers the, total gpm is divided by 4 , that will be 750 gpm., Each riser will be sized based on this value i.e. 750 gpm., Without question the plumbing fixture in this blg.will not operate, simultaneously , the diversity factor is included in Chart -1, , 62
Page 63 :
1, , Sizing a Water supply system, , 63, , The 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 if adequate sizing of pipes are provided., The sizes established must be large enough to prevent occurrence of, negative pressure in any part of the system during periods of peak demand, in order to avoid the hazard of water supply , contamination due to back, flow and back flow and back siphonage from potential sources of pollution., Main objectives in designing a water supply 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 ., , 63
Page 64 :
1, , Pipe sizing, , 64, , Pipe 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 velocity pipe 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., , 64
Page 65 :
1, , Sizing based on Velocity limitation, , 65, , In 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], , 65
Page 66 :
1, , 66, , 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, should be reduced to a reasonable minimum .the general, recommendation in this instance is 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-pressure booster-pump water supply system, , 66
Page 67 :
SIMPLIFIED STEP BY STEP PROCEDURE, FOR SIZING PIPING (67Based, 1, 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 fixture supplies. 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, , 67
Page 68 :
1, , 68, , 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 units in accordance with table (wsfu –gpm)., 4-mark on the schematic elevation adjacent to 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 demand in gallons /min or liter/sec for outlets at which demand is, deemed continuous, such as outlets for watering gardens irrigating lawn, ,air-conditioning apparatus refrigeration machines, and other using, continuously water. Add the continuous demand to the demand for, intermittently used fixtures and show the total demand at those sections, where both types of demand occur, 6-size all individual fixture supply pipes to water outlets in accordance with, the minimum sizes permitted by regulations. 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 ., , 68
Page 69 :
1, , 1.35 m/s, , 69, , V=2 m/s, , D, , 69
Page 70 :
1, How to use the pipe flow-chart, , 70, , The use of the pipe flow chart is best presented by an, example : A fairly rough steel 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, of 5 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 ) ., Now it is clear that the intersection lies between 1.1/4” and, 1” diameter . If the 1 in pipe is used , the pressure drop will, be 15 Psi/100 ft which is greater than the given 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 .I would recommend D=1.1/4” with a flow, velocity less than 3 m/s. The flow velocity is about 1.35 m/s, ., , 70
Page 71 :
1, , Size of Principal Branches and Risers, , 71, , - The required size of branches and risers may be obtained in, the same manner as the 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 one hundred (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 the sizes of pipe for the different branches so, that the total friction loss in each lower branch is, approximately equal to the total loss in the riser, including, both friction loss and loss in static, Pressure;, , 71
Page 72 :
1, , 72, , (2) throttling each such branch by means of a valve until the, preceding balance is obtained;, (3) increasing the size of the building supply and risers above, the minimum required to meet the maximum permissible, friction loss., Refer to Upfeed & down feed system ., - The size of branches and mains serving flush tanks shall, be consistent with sizing procedures for flush tank water, closets. (Courtesy of The Uniform Plumbing Code)., , 72
Page 73 :
1, , 73, , Sizing the riser diagram, D6 ?, , D1 ?, , Inlet water flow ?, , 4 Pressure relief valve, , Hot water, , 1.25 ", , D2 ?, , Electrical water heater, Cold water, , 1", , D3 ?, , 1", , 3/4 of the total fixture units are used for cold water, , H.W., , D4 ?, , D?, , D5 ?, , 73
Page 74 :
Equal friction loss, , 1, 74, , Open system, , 74
Page 75 :
1, , Sizing the various pipes of the net work, , 75, , 3/4 of the total fixture units are used for cold water, Bathtub, , WC, , ?", ?", , Bidet, , Lavatory, , Shower, , Sink, , ?", ?", , ?", , ?", , ?", , ?", , ?", , ?", , Determine the pipe sizes of the present drawing, , H.W., , 75
Page 76 :
1, Minimum size of fixture, supply pipe 76, , The 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, , Minimum size of pipe, , Bathtub, , "½, , Drinking fountain, , "8/3, , Dishwashing machine, , "½, , Lavatory, , "8/3, , single head-Shower, , "½, , flushing rim-Shower, , "¾, , flush tank-Urinal, , "½, , in flush valve1-Urinal, , "¾, , flush valve-Water closet, , "1, , flush tank-Water closet, , "½, , 76
Page 77 :
1, , 77, , Ref [2], , 77
Page 78 :
1, , 78, , General remarks on the installation of water pipes, 1- Every apartment should have a valve on the main cold water, pipe feeding this apartment. Every bathroom should have two, valves one for cold and the second for hot water pipe., 2- Each plumbing Fixture should have and angle valve for, maintenance reason., 3- Exposing pipes are installed approximately 3 cm from wall, with hangers 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 , the pipe are wrapped with jute and asphalt ., 6- Pipes crossing walls should be through pipe sleeves, A rule of thumb is that not more than two fixture should be served by a single ½” branch, , 78
Page 79 :
1, , 79, , Pressure Requirements, 1- Pressure required during flow for different, fixtures., 2- Pressure required at the inlet of the flat., 3- The hydrostatic pressure available at each shutoff valve., 4- Pressure reducer valve PRV, , 79
Page 80 :
1, , 80, , Pressure Required During Flow for, Different Fixtures, , N.P.Code USA, , Ref [8], , 80
Page 81 :
1, , 81, , Pressure Required At The Inlet Of each Flat, As it well known the Hydrostatic pressure @ shut-off valve is given by :, , P = γ×h, , Where γ is the specific weight kN/m3 & h is the pressure head in m, , The maximum pressure at the inlet of the flat is Limited to, to 30 m which is, about 2.9 bar , that , avoid excessive pressures, , If the pressure is more than 2.9 Bar :, You may need breakbreak-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 operates the most critical fixture ( for example Dish washer or shower)., Pressure Drop, P= γ x hL + Surplus pressure ( hL is the head loss due to pipe, friction ), Allowing additional pressure drop around 2525-30% for fittings on straight pipe, or calculate the effective length for minor losses as described in Fluid Mechanics, Lecture notes. It is always recommended to use the K value for the calculation of, the pressure drop., , 81
Page 82 :
Example of high riser, Building, , 1, , 82, , 24, floors, , Ref [4], , 82
Page 83 :
1, 83, The hydrostatic pressure available, at each shut-off valve., , 83
Page 84 :
R1, , 1, , R2, ELECTRICFLOATVALVE, , R3, , 3", , 84, , R4, ELECTRICFLOATVALVE, , BLOCKB, , BLOCK-B, UPPERDOMESTICWATERTANK, 2 *10000 litres ( P.ETANKS), , BLOCK-B, UPPERDOMESTICWATERTANK, 2 * 10000 litres( P.ETANKS), 3", , 21/2" FROMD.W.P-B, , 4" F.F.P, , 4"F.F.P, 4" C.W.P, , UPPERROOF, , 4" C.W.P, 3" C.W.P, , 3"C.W.P, , ROOF, 3" C.W.P, 1"C.W.P, , 1 1/4"C.W.P, 3"C.W.P, , 4" C.W.P, , 3" C.W.P, , 3"C.W.P, 1" C.W.P, , 1 1/4" C.W.P, 3"C.W.P, F.F.P, , F.F.P, , 3" C.W.P, , 24TH. FLOOR, 1" C.W.P, , Riser diagram, ( pressure reducers), , 1" C.W.P, , 1" C.W.P, , 1" C.W.P, , 3"C.W.P, , 3"C.W.P, , 3" C.W.P, , 3" C.W.P, , 23RD. FLOOR, 1" C.W.P, , 1" C.W.P, , 1" C.W.P, , 3"C.W.P, , 3" C.W.P, , 1" C.W.P, , 3" C.W.P, , 3"C.W.P, , 22ND. FLOOR, 1" C.W.P, , 1" C.W.P, , 1" C.W.P, , 3" C.W.P, , 3"C.W.P, , 1" C.W.P, , 3" C.W.P, , 21ST. FLOOR, 1" C.W.P, , 1" 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.W.P, , 3"C.W.P, , 20TH. FLOOR, 1" C.W.P, , 3/4" C.W.P, , 3/4" C.W.P, , 2 1/2" C.W.P, , 3"C.W.P, , 3/4" C.W.P, , 2 1/2" C.W.P, , 3"C.W.P, , 19TH. FLOOR, 3/4" C.W.P, , 3"C.W.P, , 3/4" C.W.P, , 2 1/2" C.W.P, , 3/4" C.W.P, D.W.P.L, , 1" C.W.P, , 2 1/2" C.W.P, , 3"C.W.P, , 18TH. FLOOR, 1" C.W.P, , 3/4" C.W.P, , 3/4" C.W.P, , 3/4" C.W.P, 3" P.R.V, , 2 1/2" P.R.V, 3" P.R.V, , 2 1/2" P.R.V, , 17TH. FLOOR, 1" C.W.P, 3"C.W.P, , 1" C.W.P, , 1" C.W.P, , 2 1/2" C.W.P, , 2 1/2" C.W.P, , 1" C.W.P, , 1" C.W.P, , 1" C.W.P, , 2 1/2" C.W.P, , 2 1/2" C.W.P, , 2 1/2" C.W.P, , 1" C.W.P, , 1" C.W.P, , 1" C.W.P, 3"C.W.P, , 16TH. FLOOR, 1" C.W.P, 2 1/2" C.W.P, , 15TH. FLOOR, 1" C.W.P, 2 1/2" C.W.P, , 2" C.W.P, , 1" C.W.P, , 2" C.W.P, , 2 1/2" C.W.P, , GLOBEVALVE( TYP. ), , 1" C.W.P, , 1" C.W.P, 2 1/2" C.W.P, , 14TH. FLOOR, , 1" C.W.P, , 2" C.W.P, , 1" C.W.P, , 2 1/2", , 2" C.W.P, , 2 1/2" C.W.P, , 13TH. FLOOR, 1" C.W.P, , 3/4" C.W.P, , 3/4" C.W.P, , 2 1/2" C.W.P, , 3/4" C.W.P, , 2" C.W.P, , 2" C.W.P, , 2 1/2" C.W.P, , 12TH. FLOOR, 1" C.W.P, , 3/4" C.W.P, , 3/4" C.W.P, , 2"C.W.P, , 3/4" C.W.P, 2"C.W.P, , 2" C.W.P, , 2" C.W.P, , GLOBE VALVE(TYP. ), GLOBEVALVE( TYP. ), , 1" C.W.P, , 11TH. FLOOR, 3/4" C.W.P, , 3/4" C.W.P, , 3/4" C.W.P, 2" P.R.V, , 2" P.R.V, 2" P.R.V, , 2"P.R.V, , 10TH. FLOOR, , 2"C.W.P, , 1" C.W.P, , 1" C.W.P, , 1" C.W.P, , D.W.P.L, , 1" C.W.P, , 2" C.W.P, , 2" C.W.P, , 2"C.W.P, , GLOBE VALVE(TYP. ), , 1" C.W.P, , 9TH. FLOOR, , 1" C.W.P, , 2"C.W.P, , 1" C.W.P, , 1" C.W.P, , 1 1/2" C.W.P, , 1 1/2" C.W.P, , 2"C.W.P, , GLOBEVALVE( TYP. ), , 1" C.W.P, 2"C.W.P, , 1" C.W.P, , 1" C.W.P, , 1 1/2" C.W.P, , 1 1/2" C.W.P, , 8TH. FLOOR, 1" C.W.P, 2"C.W.P, , 7TH. FLOOR, 1" C.W.P, , 1" C.W.P, , 1" C.W.P, , 1" C.W.P, , 1 1/2" C.W.P, , 1 1/2" C.W.P, , 1 1/2" C.W.P, , 1 1/2" C.W.P, , 6TH. FLOOR, 1" C.W.P, , 3/4" C.W.P, , 3/4" C.W.P, , 1 1/2" 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, , 5TH. FLOOR, 1" C.W.P, , 1 1/2" C.W.P, , 3/4" C.W.P, , 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, , 4TH. FLOOR, 1" C.W.P, , 3/4" C.W.P, , 3/4" C.W.P, , 3/4" C.W.P, , 1 1/4" P.R.V, , 1 1/2" P.R.V, 1 1/4" P.R.V, , 1 1/2" P.R.V, , 3RD. FLOOR, 1" C.W.P, , 1" C.W.P, , 1 1/4"C.W.P, , 1" C.W.P, , 1" C.W.P, , 1" C.W.P, , 1" C.W.P, , 1 1/4" C.W.P, , 2ND. FLOOR, 1" C.W.P, , 1" C.W.P, , 1" C.W.P, D.W.P.L, , 1" C.W.P, , 1 1/4" C.W.P, , 1 1/4" C.W.P, , 1ST. FLOOR, 1", , 3/4" C.W.P, , 3/4" C.W.P, 2 1/2" DOMESTICWATERPUMPINGLINE, , 1" G.S.P, , 1" GENERALSERVICEPIPE, , GRD. FLOOR, 3/4" G.S.P, , 3/4" G.S.P, , 3/4" G.S.P, , 3/4" G.S.P, 1 1/4" WELLWATERPIPE, , 3/4" G.S.P, , 3/4" G.S.P, , F.H.C, D.W.P.L, , POTABLEWATERINCOMINGPIPE, BLOCK-BLOWERDOMESTICWATERTANK, 8 * 4000 litres (P.ETANKS), &4 *3000litres(P.ETANKS), , 3", , 3", , DOMESTICWATERPUMPINGSTATIOND.W.P-B, 20 m3/HR@95mEACH, , Indirect pumping system, , Ref [4], , 84
Page 85 :
1, 1" C.W.P, , 1" C.W.P, 11/2" C.W.P, , 1" C.W.P, , 1" C.W.P, , 11/4" C.W.P, , 11/2" C.W.P, , MECH.ROOM2, , 11/4" C.W.P, UPPERDOMESTICWATERTANK, 3*10000litres ( P.ETANKS), , FLOATVALVE, , 85, , p.r, , p.r, , 1" C.W.P, 11/4" C.W.P, , 11/4" C.W.P, , 3", 3", , 1" C.W.P, , 1" C.W.P, 11/2" C.W.P, , 11/2" C.W.P, , 11/4" C.W.P, , 1" C.W.P, Drainpipe, , 3", , 1" C.W.P, , 19TH. FLOOR, , FLOATVALVE, , 1" C.W.P, 11/2" C.W.P, , 3" C.W.P, 11/2" C.W.P, , 11/4" C.W.P, , 18TH. FLOOR, , 11/4" C.W.P, , 17TH. FLOOR, 11/4" C.W.P, , 16TH. FLOOR, 11/4" C.W.P, , 11/4" C.W.P, , 11/4" C.W.P, , 11/4" C.W.P, , 15TH. FLOOR, , 85
Page 86 :
R1, , 1, , R2, , R3, , 86, , R4, , ELECTRICFLOATVALVE, , ELECTRICFLOATVALVE, , BLOCKB, , BLOCK-B, UPPERDOMESTICWATERTANK, 2*7500litres ( P.ETANKS), , BLOCK-B, UPPERDOMESTIC WATERTANK, 2* 7500 litres ( P.E TANKS), , 2" FROMD.W.P-B, , 3", , 3", , MECH.ROOM1, 4" C.W.P, , BOOSTERUNIT(TYPR1 - R4), PUMPS- 9m3/HR@15mHEAD, ONE STANDBYWITHPRESSURETANK200L, , 4" F.F.P, , UPPERROOF, , 4" C.W.P, 3" C.W.P, , 3" C.W.P, , ROOF, 1 1/2" C.W.P, , 1 1/4" C.W.P, , 1 1/4" C.W.P, , 3" C.W.P, , 1 1/2" C.W.P, , 1 1/2" C.W.P, , 1 1/4" C.W.P, , 1 1/4" C.W.P, , BOOSTERUNIT (TYPR2- R3), PUMPS- 6.8m3/HR@15 mHEAD, ONESTANDBYWITHPRESSURETANK200L, , 1 1/4" C.W.P, , 1 1/4" C.W.P, 2" C.W.P, , 24TH. FLOOR, , 1 1/4" C.W.P, , 11/4" C.W.P, 2"C.W.P, , 2" C.W.P, , 2" C.W.P, , 23RD. FLOOR, 11/4" C.W.P, , 1 1/4" C.W.P, , 1 1/4" C.W.P, , 11/4" C.W.P, 2", , 2" C.W.P, , 2" C.W.P, , 2" C.W.P, , 2" C.W.P, , 22ND. FLOOR, 11/4" C.W.P, , 1 1/4" C.W.P, , 2" C.W.P, , 1 1/4" C.W.P, , 11/4" C.W.P, , 1 1/2" C.W.P, , 1 1/2" C.W.P, , 2" C.W.P, , 21ST. FLOOR, 11/4" C.W.P, , 1 1/4" C.W.P, , 1 1/4" C.W.P, , 11/4" C.W.P, , 1 1/2" C.W.P, , 2" C.W.P, , 1 1/2" C.W.P, , 2" C.W.P, , 20TH. FLOOR, 11/4" C.W.P, , 1 1/4" C.W.P, , 1 1/2" C.W.P, , 1 1/4" C.W.P, , 11/2" C.W.P, , 11/4" C.W.P, , MECH.ROOM2, , ELECTRICFLOATVALVE, , 11/4" C.W.P, , 1 1/4" C.W.P, , 11/4" C.W.P, , 19TH. FLOOR, , Delayfloat -valve, , UPPERDOMESTICWATERTANK, 4 *10000 litres (P.ETANKS), , 1 1/4" C.W.P, 1 1/4" C.W.P, , 11/4" C.W.P, 3", , Drainpipe, , 11/4" C.W.P, , 3", 3", , 1 1/2" C.W.P, , 11/2" C.W.P, , 3" C.W.P, , 11/2" C.W.P, , 18TH. FLOOR, 1 1/4" C.W.P, , 11/4" C.W.P, , 1 1/4" C.W.P, , 1 1/2" C.W.P, , 17TH. FLOOR, , 11/4" C.W.P, , 11/4" C.W.P, , 11/4" C.W.P, , 11/4" C.W.P, , 11/4" C.W.P, , 1 1/4" C.W.P, , 11/4" C.W.P, , 11/4" C.W.P, , 11/4" C.W.P, , 1 1/4" C.W.P, , 11/4" C.W.P, , 11/4" C.W.P, , 16TH. FLOOR, , 15TH. FLOOR, , 2" C.W.P, , 2" C.W.P, , 2" C.W.P, , 2" C.W.P, , GLOBE VALVE ( TYP. ), , 11/4" C.W.P, , 11/4" C.W.P, , 2 1/2", , 2" C.W.P, , 2" C.W.P, , 2" C.W.P, , 14TH. FLOOR, , 11/4" C.W.P, , 1 1/4" C.W.P, , 2" C.W.P, , 13TH. FLOOR, 11/4" C.W.P, , 1 1/2" C.W.P, , 2 " C.W.P, , 11/4" C.W.P, , 11/4" C.W.P, , 1 1/4" C.W.P, , 11/2" C.W.P, , 2" C.W.P, , GLOBEVALVE( TYP. ), , 11/4" C.W.P, , 12TH. FLOOR, , 1 1/4" C.W.P, 1 1/4" C.W.P, , 11/2" C.W.P, , 11/4" C.W.P, , 11/4" C.W.P, , 11/4" C.W.P, , 11/2" C.W.P, GLOBEVALVE( TYP. ), , MECH.ROOM3, , GLOBE VALVE ( TYP. ), , 11TH. FLOOR, , Delay -Float Valve, , 11/4" C.W.P, , UPPERDOMESTICWATERTANK, 3 * 10000litres( P.E TANKS), , 3", , 3", , 3", , 11/4" C.W.P, , 11/2" C.W.P, , 11/2" C.W.P, , 10TH. FLOOR, , 1 1/4" C.W.P, , 11/4" C.W.P, , D.W.P.L, , 11/4" C.W.P, , 11/4" C.W.P, , 1 1/2" C.W.P, , 11/2" C.W.P, , 9TH. FLOOR, 11/4" C.W.P, , 11/4" C.W.P, , 11/4" C.W.P, , 11/4" C.W.P, , 1 1/4" C.W.P, , 1 1/4" C.W.P, , 1 1/4" C.W.P, , 11/4" C.W.P, , 1 1/4" C.W.P, , 1 1/4" C.W.P, , 1 1/4" C.W.P, , 11/4" C.W.P, , 8TH. FLOOR, , 7TH. FLOOR, , 2" C.W.P, , 2" C.W.P, , 2" C.W.P, , 2" C.W.P, , 6TH. FLOOR, 11/4" C.W.P, , 1 1/4" C.W.P, 2" C.W.P, , 2" C.W.P, , 1 1/4" C.W.P, , 1 1/4" C.W.P, 2" C.W.P, , 2" C.W.P, , 5TH. FLOOR, 11/4" C.W.P, , 1 1/4" C.W.P, , 11/2" C.W.P, , 2" C.W.P, , 1 1/4" C.W.P, , 1 1/4" C.W.P, , 1 1/2" C.W.P, , 2" C.W.P, , 4TH. FLOOR, 11/4" C.W.P, , 1 1/4" C.W.P, , 2" C.W.P, , 11/2" C.W.P, , 1 1/4" C.W.P, , 1 1/4" C.W.P, , 2" C.W.P, , 1 1/2" C.W.P, , 3RD. FLOOR, 11/4" C.W.P, , 1 1/4" C.W.P, , 11/4" 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, , 2ND. FLOOR, 11/4" 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, , Riser diagram, (Break pressure tanks II), , 1 1/2" C.W.P, , 2" C.W.P, , 2" C.W.P, , 1ST. FLOOR, 1 1/4" C.W.P, , 3/4" C.W.P, , 11/2" C.W.P, , 1" C.W.P, , 2 1/2" DOMESTICWATERPUMPINGLINE, , 2" C.W.P, , 11/2" GENERALSERVICEPIPE, 11/2" C.W.P, , GRD. FLOOR, , 1 1/4" G.S.P, , 1 1/4" G.S.P, , 1 1/4" G.S.P, , 1 1/4" G.S.P, , 1 1/4" G.S.P, , 1 1/4" G.S.P, 1 1/4" WELL WATERPIPE, POTABLEWATERFROMMAINCITY, , BLOCK-BLOWER DOMESTICWATERTANK, , 3", , 3", , DOMESTICWATERPUMPINGSTATIOND.W.P-B, 20m3/HR@95mEACH, DP-pump, , Indirect pumpingsystemCase study(II), , Ref [4], , 86
Page 87 :
1, , 87, , 87
Page 89 :
1, , Pressure Reducer Valve PRV, , 89, , 89
Page 90 :
1, , 90, , 90
Page 91 :
1, , 91, , The head loss due to pipe friction, & fittings, Review your “lecture notes” .Ref [5] Chap.9-10, Or refer to [10], , 91
Page 92 :
1, Now, !!, , 92, , After completing the above chapters you should be able to :, 1- Calculate the 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 indirect, water 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, enough to 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 tank or pressure reducing valve ?, , Now move on to the next part, “Pump selection”, , 92
Page 93 :
Design of pumping supply system to a building, In 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 the simplest method used, which gives acceptable results., 1, , 93, , 93
Page 94 :
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 the pipe connecting the underground tank to the overhead (, delivery ) tank and count all 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 or based on the total fixture units. ( It is not always easy to, know the number of occupants 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 value of 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., 1, , 94, , 94
Page 95 :
Design of pumping supply system to a, building ( con’t), 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 are more, convenient., 5) Continuing along the circuit chosen , select the, succeeding pipe sizes . This should be done, according to the following guides:, Determine by inspection which branch will be the, longest, or have the greatest equivalent length ., Calculate the pressure drop in the longest circuit., , 1, , 95, , 95
Page 96 :
Design of pumping supply system to a, building ( con’t), 6-Calculate :, a) The total effective length E.L which is:, The actual pipe length + Equivalent length (due to, fittings and valves etc.)., , L eff . = L + ∑ L e, 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 ., , hL = h1 × L eff ., 1, , 96, , 96
Page 97 :
Design of pumping supply system to a, building ( con’t), 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 = γx hAx QV ., (Where γ 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., 1, , 97, , 97
Page 98 :
Safety Margin, To avoid any miscalculation during pump selection, it, is recommended to apply a safety margin of, around 5% for the estimated flow rate & 10 % for, the estimated head., For example :, Estimated Flow rate Q = 30 L/s & Head 25 m, The recommended flow & head will be :, Q= 30L/s +5% , & H =25m +10%, , 1, , 98, , 98
Page 99 :
Design of pumping supply system to a, building ( con’t), 8- The shaft power of the pump can be determined, by dividing water power by the pump efficiency., , Pump Power =, , γ × hA × QV, η, , The motor power of the pump can be determined, by dividing water power by the overall pump, efficiency., , γ × hA × QV, Pump Motor Power =, η0, 1, , 99, , 99
Page 100 :
The most popular types of, centrifugal pump used for cold, water supply systems in buildings, are:, , For further details Refer to Ref [10], , 1, , 100, , 100
Page 101 :
Vertical Multistage Pumps, , 1, , 101, , 101
Page 102 :
Horizontal multistage pump, , 1, , 102, , 102
Page 103 :
Vertical – Line shaft submerged-pumps, The usual pumping depth is, about 120 m. Nowadays, a, depth of 250 m can be, obtained with multistage, turbines., •This kind of pumps is used, for clean water, sewage, irrigation and fire fittings,, etc., •A broad selection of driver, heads is available to drive the, pumps by most common prime, movers., •High performance and low, maintenance., 1, , 103, , 103
Page 104 :
TURBINE, VERTICAL TYPE, MULTISTAGE,, DEEP WELL, SUBMERSIBLE, These pumps develop high head, by using a series of small, impellers rather than a large, single one. The characteristic, curves for such pumps depend, upon the number of stages or, impellers. Each impeller has the, same characteristic curve and, the final curve is obtained by, adding them up. The total head, at a given discharge is the sum, of individual heads (case of, series pumps). This kind of, pumps may deliver the liquid up, from 400 to 500 m depth., These pumps are commonly used, in tube wells, deep open wells,, etc., , 1, , 104, , 104
Page 105 :
SUBMERSIBLE PUMP, , For high heads and low flow., DEEP WELL, 1, , 105, , 105
Page 106 :
Booster pump, Packages, , 1, , 106, , 106
Page 107 :
( Auto-pneumatic, pressurized, system ), Boosted water directly to each floor., This method of providing high rise buildings with water supplies is more common, as it does not require electrical wiring, from ground/basement where the booster pump is situated to the high, high level tank room where the float switches are located in, the storage tank and drinking water header., There are a number of specialist pump manufacturers who offer water, water pressurization plant similar to that shown in the, pressurization unit drawing.The cold water down service will require, require pressure reduction at intervals of five storeys to avoid, excessive pressures at the draw off points. The pressure vessel is sized to hold the calculated quantity of water, as, a rule of thumb the vessel capacity is about 15 minutes, minutes the actual discharge., As water is drawn off through the high level fittings, the water, water level in the, vessel falls. At a predetermined low level a pressure switch activates, activates the booster pump., The capacity of the pneumatic pressure tank :, Vmin =, , net volume, Degree of admission, , The net volume = Qmax. × T , where Qmax = Peak water demand ,, T = 15 minutes storage of Qmax, , where P2 and P1 are the Maximum and minimum allowable, operating pressure in absolute values., , Degree of admission =, , P2 − P1, P2, , 1, , Ref[1], , 107, , 107
Page 108 :
Booster pump, pressurized system, “balloon” type, , 1, , 108, , 108
Page 109 :
Booster Pump, Pressurized System “Balloon” Type, Used for direct supply, system , e.g. Villa etc.., , 1, , 109, , 109
Page 110 :
Example, , 1, , Ref [4], , 110, , 110
Page 111 :
Sphere booster Units, Is used for boosting the, water to top floors, when, the hydrostatic pressure, at the inlet of the flat is, less than the recommended, pressure requirement ., Location : In the attic or, on the roof., As a rule of thumb the vessel, capacity is about 2 minutes the, actual pump discharge., 1, , 111, , 111
Page 112 :
Domino booster, Is used for boosting the, water to top floors, when, the hydrostatic pressure, at the inlet of the flat is, less than the recommended, pressure requirement ., Location : In the attic or, on the roof., , 1, , 112, , Ref [7], , 112
Page 113 :
1, , Discharge & pressure head, , 113, , valve, , Estimated pump’s, discharge Gpm or m 3/h, , D?, , Estimated, Pump ‘s, Head m, , Static (hs), , Each pump drawing should have the value of H & Q ., , 113
Page 114 :
Review of the Performance, Characteristics curves of a, water centrifugal pump, •Q-H curve, •Efficiency curve, •Shaft power curve, •NPSH, , Review, 1, , 114, , 114
Page 115 :
1- Head capacity curve, •The available head produced by the pump, decreases as the discharge increases., •At Q= 0, the corresponding head is called, shut off head point (1), • Point (2) is called run out point below, which the pump cannot operate., operate.&should be shut down, , “end-of curve”, , 1, , 115, , 115
Page 116 :
2- Efficiency curve, The efficiency of a centrifugal pump is the ratio of water, power to brake power., , ηP =, , Water power, Shaft power, , The highest efficiency of a pump, occurs at the flow where the, incidence angle of the fluid entering, the hydraulic passages best, matches with the blade angle. The, operating condition where a pump, design has its highest efficiency is, referred to as the best efficiency, point B.E.P., , 1, , 116, , 116
Page 117 :
3- Power curve, The shaft power is determined in order to select a motor for the pump., The shaft power can be determined directly from the manufacturer’, manufacturer’s, catalogue plot or calculated from the following formula :, , shaft Power =γ × H × Q η, From the equation, it is clear that the main, parameter affecting the shaft power is the, discharge and not the head., head. This is becau, of the increase in the discharge for the same, pipe diameter leading to additional losses, which need more power to drive the pump., pump., , 1, , 117, , 117
Page 118 :
4- NPSH required curve, The Net Positive Suction Head Required is the minimum energy, required at the suction flange for the pump to operate satisfactorily, away from cavitation problem ., The NPSHR required increases with an increase in discharge. ,, Operating the pump near the runrun-out point should be avoided, .It may lead to cavitation problem as the NPSHR value is high, , 1, , 118, , 118
Page 119 :
How to draw the pipe system, resistance curves?, , 1, , 119, , 119
Page 120 :
1, , 120, , Sizing the discharge pipe of the pump, & the Pumping Rate, In order to size the discharge pipe which feed the roof tanks , the, following data are needed:, 1- The capacity of the roof tanks, 2- The pumping rate., N.B. To avoid disturbance & noise the Pumping time is limited to 4 hours, /day ( CIBSE B4)., If for example , the Pump has to refill the empty overhead tank in 4, hours ,the pumping rate becomes 40 m3 / 4 h = 10 m3 /h., If however ,the Pump has to refill the empty overhead tank in 2 hours, The pumping rate becomes 20 m3/h ., Decision has to be made by the consultant engineer to determine the, pumping time ,for example one or two hours ., The pumping rate is not the operating point or duty point of the pump., It is an estimated value used to estimate the flow rate in the pipe. The, actual pump discharge is obtained from =>Intersection of the pipe, system curve and pump performance curve., , Refer to your ” Lecture notes “ [Ref [6] “ ., , 120
Page 121 :
1, , 121, , The estimated pump’ s head, As it is known that , the role of the pump is to, overcome loss + elevation difference + dynamic, head., V22, h A = hL + Z 2 − Z 1 +, 2. g, •The elevation difference represents the total static, head which, is the vertical distance between the water, w, surface level of the suction and discharge tanks., • The dynamic head is too small, practically it can, be neglected., , 121
Page 122 :
“Operating point or duty point “, A centrifugal pump operating in a given system will deliver a flow rate, corresponding to the intersection of its head-capacity curve with the pipe, system curve. The intersection point is called “ Duty point or operating point”, , At this point the head, required from the pump, = the head given by the, pump .Also At this point, the pump would deliver, the maximum discharge, Qmax ., 1, , 122, , 122
Page 123 :
Pump selection limitations, , 15 L/s, 17 L/s, , 13 L/s, , 1, , 123, , 123
Page 124 :
“Pump selection “, Pump is selected based on the B.E.P. or nearly so ., , 1, , 124, , 124
Page 125 :
1, , The best efficiency point (, B.E.P.) is the point, of highest efficiency of the pump, curve , which is the, design operating point., The pump is selected to operate, near or at the B.E.P., B.E.P. However ,, the pump ends up operating over, wide range of its curve, that is, due to the pipe system curve, changes ( case of valve maneuver, or branches pipes using, motorized valve, static head, deviation etc.., 125, , 125
Page 126 :
Pump’s power, Mono-block, , 1, , 126, , 126
Page 127 :
The hydraulic power or water power is given by:, , water power = F ×V = P × A ×V = γ × QV × hm, S.P =, Input power=, , water power, , ηP, , Water power, Pumpefficiency, ×Transmissi, on efficiency, ×Motorefficiency, , Pump efficiency & motor power is selected from the manufacturer catalogues., catalogues., For Example ; The Transmition efficiency is taken as follows:, 1- Case of shaft coupling = 1 ,, 2- Case of flat belt Transmition = 0.9 to 0.93, 3- Case of VV-belt Transmition = 0.930.93- 0.95., 0.95., 1, , 127, , 127
Page 128 :
Motor Power selection, There is no simple rule of thumb in motor selection.. Each, manufacturer suggest a safety margent for their motor, selection., Example: KSB pump catalogue presents the follows, estimation values :, • Example:, , •UP to 7.5 kW add 20%, • From 7.5 - 40 kW add approximately 15%, •From 40 kW and above add approximately, 10%., , 1, , 128, , 128
Page 129 :
Pump’s power, , Manufacturer, Pump’s power, End curve, , Required, Pump’s Shaft, power, , Constant speed, Monoblock- Pump, 1, , 129, , 129
Page 130 :
Class exercise, Select the size of the pump from the coverage chart shown in, the accompanied figure , assuming that , the estimated head, and discharge are h= 30 m & Q= 30 m3 /h respectively., Solution:, Enter the chart at Q= 30 m3 /h and move vertically up to the, line of intersection with, h= 30 m. The selection charts give the following pump, selections for the present data:, CN 40-160 or CN40-200 at n =2900 rpm. The CN40-160 is, selected for the reason of economy., After this preliminary selection, you will be able to analyze the, performance characteristic curve CN40-160, CN: Standard motor, 40 mm delivery output, 160 mm impeller diameter, 1, , 130, , 130
Page 132 :
Class exercise, A centrifugal pump is used to supply water to the overhead tank, located at the top of a 10- floor building . The capacity of the, overhead tank is 30 m3., 1- Estimate the size of the rising main to overhead tank., 2- Select the most suitable pump from the Lawora- pump, catalogues., 3- Estimate the power required which fits the water pipe system., 4- Discuss the results., Assuming that:, The total length of the pipe is 50 m., The elevation difference is 31 m. ( from minimum water level of the, underground level up to the top Float switch of the overhead tank), 2 gate valves full open and 6 (90 standard elbows) and one check, valve swing type. Other losses are neglected., The maximum running time of the pump is about 2 hours /day., The pumping of water is controlled automatically using automatic, water level switches., 1, , 132, , 132
Page 133 :
Class exercise, A centrifugal pump is used to supply water to a, 10- floor building, which consists of 35 flats., Each flat is occupied by 6 persons., 1-Work out the daily water requirement, the, underground and overhead tank capacity., Assuming that, each person requires 35 gal of, water / per day., 2- Estimate the pumping rate of the pump., The pumping of water is controlled automatically, using automatic water level switches., , 1, , 133, , 133
Page 134 :
Variable Speed Pumps, Driven by Frequency, Converters ., Direct supply system . Used, In Hotels , villas , Hospital, etc.., , 1, , 134, , 134
Page 135 :
Speed, reduction, , Pump’s, Shaft, power, , 1, , 135, , 135
Page 136 :
Summary, Using constant speed centrifugal pump, ,it is not possible to get a const flow rate, under variable pressure condition., (@BEP), z Using constant speed centrifugal pump, ,it is not possible to get a const, pressure under variable flow. (@BEP), Variable speed pump accompanied with, frequency inverter (VFD) can do So!, z, , 1, , 136, , 136
Page 137 :
VFD-pump can maintaining a constant, pressure at variable flow, , , It can generate a constant pressure at variable flow, H, , Q, , It can avoid water-hammer due, to pump stopping gradually, , , , It, , can save energy, , The RPM increases or, decreases automatically to, keep the pressure constant, Ref [7], , 1, , 137, , 137
Page 138 :
Compensation for system losses (according system, curve), , , , H, , Using a differential, pressure transmitter, the, pump is balancing the, friction losses of system, curve., , Q, , , As the discharge increases the, pressure increases to, compensate for the added, [7], friction losses in theRef, system., , It can save energy up to, 60 % versus a full speed, pump., 1, , 138, , 138
Page 139 :
Maintaining a constant flow rate, , , , , , , , H, , It can guarantee a, constant flow at, variable head, , Ref [7], , It can avoid to run out of, the curve when the, system needs low head, , Q, , As the discharge changes .The, VFD increase the rpm i.e. the, pressure to maintain a, constant discharge., , It can save energy, , 1, , 139, , 139
Page 140 :
What happens to Flow, Head and Power with, Speed?, , Q ~ RPM, H ~ RPM2, SP ~ RPM3, , 1, , 140, , 140
Page 141 :
1, , 141, , 141
Page 142 :
Affinity laws (For the same pump), , 1, , 142, , 142
Page 143 :
Affinity laws, Doubling the pump rotational, speed leads to:, 1- Double the discharge., 2- Increase the total head, value by a factor of 4., 3- Increase the power by a, factor of 8., 1, , 143, , 143
Page 144 :
Class Exercise, A pump delivers 2000 L /min. of water, against a head of 20m at a efficiency of 70, % and running at shaft rotational speed of, 3000 rpm. Estimate the new pump, characteristics if the rotational speed of, the shaft is changed to 4000 rpm. Assume, the pump efficiency is constant ., , 1, , 144, , 144
Page 145 :
Summary of Exercise :, , 1, , 145, , 145
Page 146 :
Consider a 15-floor building with four flats ( three bedroom) each floor. Each flat, having one drinking water point. Minimum mains water pressure is 2 bar ( gauge) and, floor heights are 3 m. Calculate 1) Cold water storage tank capacity 2) booster pump, head & flow 3) Select a pump from Lawora catalogue ( using 4psi/100 ft) . Assuming, 5 standard elbow , 2 gate valves , one check valve ( swing type) . Other losses are, neglected. Pipe material is galvanized steel., , Home work, Assume that,, the Pumping, time is 4 hours, , Assume missing, data if any., , 1, , 146, , 146
Page 147 :
A 30-storey office block having a central toilet accommodation . Each floor, occupied by 100 person . Floor to floor height is 3 m. Select a pump for this, configuration using the velocity limitation method. Assuming 5 standard elbow, , 2 gate valves , one check valve ( swing type) . Other losses are neglected., Pipe material is galvanized steel, Assume that,, the Pumping, time is 3 hours, , Home work, , Assume missing, data if any., , 1, , 147, , 147
Page 148 :
Next lecture, , z, , Hot water distribution system in building, , 1, , 148, , 148
