Full Report - Feasibility Study KSCS K-Exim

<Figure 5.12> Hydraulic gra 5-35

Chapter 5. Conveyance System Planning adient for phase 2 (Case 1) 5

Feasibility Study for Karian – Serpong Raw Water Conveyance System (K <Table 5.24> Hydraulic calcu No. Measuring point Length Ground Design Velocity (m) level (m) coefficient flowrate (m3/s) 1 Karian dam 2 Conveyance tunnel 1,329 12.4 120 12.4 120 3 Inflow pipeline 110 12.0 120 12.0 120 4 1-Sta.00+000 - 45.9 12.0 120 11.80 120 5 1-Sta.01+292 1,292 68.8 8.20 120 6 Main line 1-Sta.14+253 12,961 52.9 1st line 8.00 120 7 (Inter- 1-Sta.18+582 4,329 47.1 12.0 120 12.0 120 8 connected) 1-Sta.30+334 11,752 29.3 12.0 120 11.80 120 9 1-Sta.47+925 17,591 50.8 8.20 120 10 2-Sta.00+000 - 45.9 8.00 120 11 2-Sta.01+292 1,292 68.8 0.20 100 3.60 120 12 Main line 2-Sta.14+253 12,961 52.9 0.20 110 2nd line 13 (Inter- 2-Sta.18+582 4,329 47.1 14 connected) 2-Sta.30+334 11,752 29.3 15 2-Sta.47+925 17,591 50.8 16 Maja 1,200 46.0 17 Solear 4,750 46.0 18 Parung Panjang 4,800 58.3 5-36

KSCS), Indonesia ulation for phase 2 (Case 2) Design Head Hydraulic Residual Remarks Diameter flow loss head head (m) (m) (m) M.W.L (m) speed (m/s) Pressurize 45m 56.430 Maja branch Solear branch 4.00 0.987 0.249 56.181 Parung Panjang 3.20 1.542 0.061 56.120 branch Serpong end point 2.00 1.910 - 101.12 55.22 Pressurize 52m 2.00 1.910 1.83 99.29 30.49 Maja branch 2.00 1.880 18.41 80.88 27.98 Solear branch Parung Panjang 2.00 1.300 5.95 74.93 27.83 branch 2.00 1.450 8.25 66.68 37.38 Serpong end point 2.00 14.96 51.72 0.92 Install PRV 2.00 1.910 - 101.12 55.22 2.00 1.910 1.83 99.29 30.49 2.00 1.880 18.41 80.88 2798 2.00 1.300 5.95 74.93 27.83 2.00 1.360 8.24 66.69 37.39 1.80 14.97 51.72 0.92 0.35 2.079 21.601 59.52 13.52 1.35 2.515 17.891 57.16 11.16 0.60 0.707 5.248 61.50 3.2 6

<Figure 5.13> Hydraulic gra 5-37

Chapter 5. Conveyance System Planning adient for phase 2 (Case 2) 7

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia - Case 2 (interconnected operation of the first and second phase pipelines) In case 2, the hydraulic calculation is made based on the condition in which the interconnected pipelines are installed to connect the first phase pipeline to the second phase pipeline. The water is to be pumped with the pump head of 45m and supplied to the Serpong, Maja, Solear, and Parung Panjang WTPs. The Rangkas Bitung Pump water is pumping the water with the pump head of 52m and the water is supplied to the Rangkas Bitung WTP. The hydraulic in Case 2 is calculated using the EPANET, a U.S. EPA’s distribution analysis network, and the results of the hydraulic calculation show that the residual heads of Maja and Solear WTPs stand at relatively high levels between 11.16m and 13.52m, thus it is necessary to consider continuously using pressure-reducing valves already installed. The results of hydraulic calculation for the interconnection of the first and second phase pipelines are shown in <Table 5.24> and the hydraulic gradient line is shown in <Figure 5.13>. ③ Review of hydraulic calculation results In the hydraulic system, it is ideal that the residual head is minimized at each endpoint and there is no residual loss. The results of the hydraulic calculation based on the residual head at the inlet of the water treatment plant are summarized in <Table 5.25>. <Table 5.25> Residual head at the inlet of WTP Phase 1 Single operation of the Interconnected operation phase 2 pipelines of the phase 2 pipelines WTP Residual Action Residual Action Residual Notes head taken head taken head - Rangkas Bitung (m) (m) (m) Maja - - PRV Solear 2.50 Not 2.50 PRV connected - Parung Panjang 17.79 13.52 Serpong Not connected 30.95 PRV 16.89 PRV 11.16 PRV 4.58 - Not - 3.2 - connected 2.0 - 9.42 - 0.92 - In general, it is desirable to have dual pipelines which allow the other pipeline to keep conveying water in the event of failure of one pipeline. There are relatively high levels of the residual head at the inlet of the Maja and Solear WTPs. However, if an interconnected operation of the first and second phase pipelines is conducted, which is our final goal to achieve, it is deemed all of WTPs will be operated stably with no excessive residual head. 5-38

Chapter 5. Conveyance System Planning Pressure reducing valves will be installed at the inlet of the water treatment plant. This allows an operator to directly measure the inflow rate and residual head for an appropriate control of the operation. If these valves are installed in the conveyance pipelines, there may be a confusion between the conveyance pipelines trying to reduce pressure and the water treatment plant trying to control inflow rate. Therefore, a WTP project provider needs to consider installing pressure reducing valves when planning the WTP. In a 2014 report on master planning of Karian – Serpong conveyance system and water treatment plant PPP, a high head (87m) and low head (47m) pumps are planned to be operated separately. In this case, it is impossible to combine the operation of the high and low head pumps, which in turn makes the interconnected operation of two dual line pipelines an impossible option. That is, an enormous amount of money invested in the construction of two dual line conveyance pipelines would only end up being useless because the two pipelines do not complement each other. Therefore, a more enhanced plan is established in this study. To stably supply water to each water treatment plant, the required pump head is 50m, enough for the first phase and for the second phase case 1. For the second phase case 2, the pump head of 32m is needed. Pressurization with the pump head of 32m makes more economic sense than pressurization with the head of 50m, hence, it is deemed reasonable to operate with the head of 32m designed for the second phase case 2. To operate the system as case 2, the interconnected pipelines, which connect the first pipeline to the second one, are planned. The flow rate and water pressure are planned to be adjusted in each pipeline, as well. 5.4.3 Determination of pipe diameter (1) Determination of pipe diameter 1) Design flow velocity It is economical to make the flow velocity as large as possible within a range of the difference in elevation between the starting and end points, which leads to a minimum diameter of the pipe. Since the diameter of the pipe is determined by given hydraulic conditions, it is designed within the maximum permissible flow velocity. On the other hand, if the hydraulic gradient is large, the threshold for the maximum velocity of flow is planned at 3.0m/s so that the pipelines do not wear down by the flow velocity inside the pipe. At the same time, the minimum velocity of flow is planned more than 0.3m/s to prevent sedimentation of sand particles. 2) Determination of diameter The hydraulic gradient is secured to satisfy the required head from the branch point to each water treatment plant. The flow velocity is increased within the allowable velocity according to the size of the diameter so that the cross-sectional area becomes economical. 5-39

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia The conveyance system plan is established by considering the phased water supply plan for each target year of 2021 (phase 1) and 2031 (phase 2). The first pipeline of the main conveyance pipeline is the single pipeline with the length of 47.9km and the diameter of 2,000mm is planned to supply water of 6.55m3/s. The second pipeline of the main conveyance pipeline is the dual pipeline with the length of 47.9km and the diameter between 1,800mm and 2,000 is planned parallel to the first pipeline of the mainline route. The scope of the first phase project is to supply 4.6m3/s of water (which is the amount to be supplied to the Serpong water treatment plant) via the first pipeline of the main conveyance pipeline. The water supply plan by phase is shown in <Figure 5.14>. <Figure 5.14> Water supply plan by phase (2) Economical diameter In deciding on an economical diameter, the flow inside the pipeline is categorized into two types, natural flow by gravity and pressure flow by the pump. As for gravity flow pipelines, it is economical to determine the diameter as close as possible to the minimum hydraulic gradient by utilizing the differential head between the starting and end points. As for pressure flow pipelines, it is better to review the correlation between the diameter and power cost which varies according to the diameter size as well as installation cost of the pipelines. In other words, the conveyance pipeline in this project is a pressure conveying pipe, if the diameter of the pipe is large for the same flow rate, the cost of installation becomes greater but the power cost is reduced as there is lower friction head loss, and vice versa. (if the diameter of the pipe is small, the power cost becomes greater while the installation cost is reduced) Hence, the most economical diameter is where the sum of the present value of the 5-40

Chapter 5. Conveyance System Planning cost of pipeline installation invested for a certain period of time and the present value of the pump-related power cost is the lowest. <Figure 5.15> Economical diameter depending on pressurization method In this study, the economical diameter is reviewed in connection with the main conveyance pipeline, by considering empirical values obtained in Korea on the present value for installation and operation costs. The economical diameter for the main pipeline is shown in <Table 5.26>. The installation cost is estimated by applying the soil burial cost per diameter and the power cost is estimated by converting power cost for 35 years to the present value based on the required power when a pump delivers water of 1,000m3/day 1m. Since the branch conveyance pipeline is branched from the main pipeline and connected to each water treatment plant, the hydraulic head at the branch point plays a more important role in deciding the diameter. Thus, the economical diameter for the branch pipeline is not reviewed. <Table 5.26> Economical diameter by pipeline (Unit: USD) Flow rate Diameter Head Power cost Construction Total Reasonable Present cost present choice Classification loss value (m3/s) (m3/day) (mm) (m/km) Yearly value First 1,800 2.8079 164 2,374 3,254 5,628 ○ pipeline 2,000 1.6809 98 1,421 3,840 5,261 ○ 2,200 1.0567 62 893 4,493 5,386 6.55 565,920 1,800 2.2781 119 1,720 3,254 4,974 of 2,000 1.3638 71 1,030 3,840 4,869 Main mainline 2,200 0.8573 45 647 4,493 5,140 conveyance pipeline Second pipeline 5.85 505,440 of mainline 5-41

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia 5.5 Selection of pipeline materials 5.5.1 Selection of pipe type (1) Selection of pipe type Based on the approximate diameters of a pipe determined through hydraulic calculation, the watertightness and strength of water pressure inside the pipe are technically reviewed. Then, economic efficiency, buildability, maintenance and stability are comprehensively examined. As a result, a steel pipe with the compressive strength of 10kg/cm2 is selected for this project. The following are the technical requirements and instructions and procedures to be considered when selecting the type of pipe. (2) Matters to be considered In selecting the type of a pipe, matters including stability against internal and external pressure as well as environmental and construction conditions must be considered. And the chosen type and diameter must have the strength that can withstand in any circumstances. The maximum hydrostatic pressure and water hammer should be considered as internal pressure and earth pressure, surface load, and earthquake should be considered as external pressure. Plus, safety against non-equilibrium and differential settlement in the deformed pipe fittings should be taken into consideration. In terms of environmental conditions, it is necessary to examine the surroundings of the installation location to see if any special welding or construction method is required. As part of this effort, protection works of the deformed pipe fittings or anti-corrosion measures should be reviewed along with construction conditions such as underground installation and traffic condition. (3) Matters to be aware of The pipe must have sufficient strength and good water tightness that are stable against various loads. It must have low resistance to the flow of water and excellent durability and anti-corrosion property. It should be easy to construct and inexpensive. When choosing a pipe, it is necessary to examine the stress and deflection calculated by using the intrinsic material strength of the pipe so that the pipe can satisfy design standards in any circumstances. The pipe should maintain a good distribution of water over a long period of time. Matters including the corrosion of the concrete pipe in the strongly acidic ground, and the corrosion and electrical erosion of the steel pipe and cast-iron pipe should also be considered. Depending on the permissible deflection of the pipe, pipes are classified into the rigid pipe and the flexible pipe. The permissible deflection is less than three percent in the rigid pipe, and more than three percent in the flexible pipe. The rigid pipe includes concrete pipe and asbestos cement pipe, and the flexible pipe includes ductile iron pipe, steel pipe, rigid polyvinyl chloride pipe, polyethylene pipe, and reinforced plastic pipe. 5-42

Chapter 5. Conveyance System Planning (4) Selection procedures After choosing an approximate diameter of the pipe through the hydraulic calculation review, the design water pressure is determined by reviewing facility conditions such as the type of conveyance pipe and method of water transmission. First, based on the results of hydraulic calculation, the type and specifications are roughly determined. Next, the pipe type to be used is decided by examining the water tightness of the joints and the internal water pressure strength of the pipe. And then, the structural design review on the chosen pipe is conducted. In a case where multiple pipe types are selected even after such technical review, a comprehensive review will be carried out, which will examine the conditions of a site where the pipeline is to be installed, construction conditions, maintenance, and safety, on top of the comparison of economically feasible conditions. (5) Comparison of pipe types Among the six pipes currently used or developed for water works, candidate pipe types that are applicable to this conveyance system are ductile cast iron pipes that have been commonly used, steel pipes, and glassfiber reinforce plastics (GRP) pipes that are recently considered being used or have been applied to some water works construction. To decide a pipe type suitable to this project, each candidate’s durability, watertightness, buildability, economic feasibility, and maintenance are comprehensively examined, and the comparison results are shown in <Table 5.27>. <Table 5.27> Pipe type comparison Classification Polyethylene coated steel GRP pipe DCIP pipe Shape Standards D80 ~ D3,000mm D150~D2,400mm D80 ~ D1,200mm Material Weight • External : steel pipe + • Glassfiber + unsaturated • Carbon + silicon + polyethylene polyester + sand manganese + phosphorus + sulfur • Inner : F.B.E (Fusion Bonded Epoxy Coating) or • Inner : cement lining, liquid epoxy resin paint epoxy powder for waterworks • Heavier than other types • 1.2 times the wrapped steel • Lighter (one third or one pipe for water works fourth the weight of cast iron pipe) 5-43

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia Classification Polyethylene coated steel GRP pipe DCIP pipe • Excellent corrosion- and • Corrosion behavior is • Polyethylene coating chemical resistance similar to unbroken copper prevents corrosion pipe. • High stiffness and high Durability Corrosion, elasticity • Corrosion takes place chemical slower than iron resistance • The pipe is a flexible pipe and continuous, so • Cement lining has good Shock • High strength and great favorable to apply to soft corrosion- and chemical resistance resistance against ground or subsidence- resistance internal/external shock prone area Foundation ground • Thick, high strength, and • The pipe is a flexible pipe • It achieves water-tightness great shock resistance and continuous, so by using special rubber favorable to apply to soft rings applied to coupling • Despite its discontinuity, ground or subsidence- method and socket-type the pipe has tyton and prone area ones, but subject to leakage mechanical joints so can be due to instable connectors applied to soft ground or Tensile strength 41 5~55 subsidence-prone area (kgf/mm2) • High pressure pipe : 43 Hydro-static • High pressure pipe:100m 100m ~ 160m head • Ordinary pressure • High pressure pipe:100m • Safe to be used for • Ordinary pressure pipe : pipe:75m transmission to high head pump 75m Inner • Welded joints allow • Low pressure pipe : 45m pressure transmission to high • Not as strong as the steel • Safe to be used for pressure pump, safe against pipe, and needs to be Pressure a certain degree of pressure cautious not to give shock transmission to high head head during construction pump External pressure • The pipe itself is a steel • Safe against galvanic • Made up of ferrite structure pipe, so has strong corrosion sintered for hours, and is resistance against external soft material with high shock or impact like traffic • Strongly resistant to strength load and earth pressure corrosion • Galvanic corrosion rarely Contact Electric • Has an excellent electrical occurs environment corrosion insulating property that prevents galvanic corrosion • In seawater 0.066mm/year and electric corrosion Corrosion • Strongly resistant to corrosion 5-44

Chapter 5. Conveyance System Planning Classification Polyethylene coated steel GRP pipe DCIP Build-ability pipe Economic feasibility • Its light material makes • Heavy weight makes Maintenance • Lighter than cast iron pipe, transportation and transportation and handling but heavier than light construction easy, but difficult Conclusion material pipe. vulnerable to pipe floating by buoyancy • With rubber ring joints, • Transportation and good build-ability and easy construction are not easy • Water expansion rubber to repair ring joints using seamed • Welded joints require pipe makes good • No special protection work longer construction period buildability is needed on bent pipes pressed joint • Easy to repair. But inner • Special protection work on coating can’t be done once bent pipes is needed • Pipes are expensive, not the welding is finished on economical site • Construction completes quickly • With accumulated expertise • Affected by climate and experiences in condition • The larger the diameter, the construction and more economical it maintenance • Installation costs (pipe and becomes joints) are high. • Maintenance costs are low, • Water supply pressure pipe but large pipes are not easy • Being a long large pipe is used on a small scale. to repair in an emergency saves construction costs. • Easy to repair in an • The safest against external • Easy maintenance since it emergency (leakage) loads among pipes currently is possible to repair leakage used in Korea. without shut off • Extra caution is needed when connecting seamed • Accounts for 65% of • Weld joint method is the pipes. pressure pipes for safest method against waterworks in Korea. leakage. • Has good buildability and strength, excellent anti- • Easy to repair and install • With an automatic welding corrosion and anti-chemical branch pipe without device applied, stability, shutting off water supply buildability, and economic • The larger the diameter, the feasibility are maximized more beneficial economically. • Large diameter pipes are strong against external • Strong against soft ground shock. subsidence • Easy to repair without shut • Thermosetting resin off. material can’t be recycled or reused. • Safe on the soft ground, but construction takes longer • Environmentally than GRP controversial when pipe is deformed, sand layer inside the glassfiber can be separated 5-45

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia 5.5.2 Determination of pipe thickness When determining the thickness of the installed steel pipe, it is necessary to consider factors including internal pressure, external pressure, differential settlement, and seismic load. The thickness of the steel pipe must be greater than the minimum thickness, less than 5 percent of the deflection by internal/external pressure, less than 0.1 percent of the axial deflection caused by differential settlement, and no more than 0.3 percent of the axial deflection caused by seismic load. The allowable tolerance for the thickness in the production of the steel pipe must be ±50 ㎛ and less, but this is not taken into account when deciding the thickness. (1) Standards for the minimum thickness The standards for the minimum thickness are as follows: t = 2D88, (when nominal diameter is D1,350mm and less) t = D+405008, (when nominal diameter is more than 1,350mm) (2) Thickness by internal pressure The thickness is calculated by applying a larger value between the two values of the internal water pressure (hydrodynamic pressure + water hammer pressure, or hydrostatic pressure) P ×d t = 2σsa σsa : allowable stress of the pipe (1,400kg/cm2) P : water pressure inside the pipe (kg/cm2) d : diameter of the pipe (mm) t : thickness of the pipe (mm) (3) Thickness by external pressure The followings must be complied with in calculating the thickness by external pressure. • The thickness must be determined according to external loads such as truck load (for traffic route, if necessary) based on the soil parameters of the ground that are applicable to most of the design section. To secure soil parameters, construction method and quality control standards must be specified in the specifications. • To prevent the painting inside the pipe from being damaged by external pressure including backfilling after the installation of steel pipes, earth pressure, and passing vehicles, the circumferential deflection of the steel pipe must be less than 5 percent of the diameter. If it is the cement mortar lining pipe, the deflection must be less than 3 percent. • The bending stress of the bottom due to external pressure must be no more than the permissible stress of the pipe. 5-46

Chapter 5. Conveyance System Planning The method of calculating external pressure is as follows: ① Earth pressure by the depth of cover - When the depth of cover (vertical excavation) is less than 200cm due to the construction of earth retaining wall such as sheet pile Wv = γs × H Wv : earth pressure by the depth of cover (kg/cm2) γs : unit weight of earth (kg/cm2) H : depth of cover (cm) - For an ordinary excavation Ws = Cd × γs × Bd Wv : earth pressure by the depth of cover (kg/cm2) γs : unit weight of earth (kg/cm2) Cd : Trench constant (Marston formula) ② External pressure due to truck load Wt = 2n∙P ×(1+i) [n∙L+(n−1)×C+b+2H∙tanθ]×(a+2Htanθ) Wt : external pressure by truck load (kg/ cm2) P : weight supported by rear wheel (1) of truck (kg) n : number of trucks parallel to occupied width L : center-to-center spacing of real wheel (cm)(175cm is generally applied) C : center-to-center spacing of real wheel between adjacent trucks (cm) (100cm is generally applied) b : earth width of real wheel (cm) (50cm is generally applied) θ : angle of dispersion (45° is generally applied) I : impact coefficient ③ Deformation of the pipe ∆X = �2Ks (Wv+ Wt)× R4� [������������������������+0.061������������ × ������������3] ΔX : lateral deformation of pipe (cm) R : mean radius of pipe (cm) E : elastic coefficient of pipe (2,100,000kg/cm2) E' : reaction coefficient of earth (kg/cm2) I : geometrical moment of inertia per unit width of pipe (cm3), I= t3 12 Ks : lateral deformation coefficient determined by the supporting angle 5-47

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia (4) Determination of pipe thickness The thickness of the straight pipe is calculated according to the applied water pressure and surrounding conditions for each section, and the results are shown in <Table 5.28>. Although the minimum cover depth in design standards is 150cm (0.15m) and more, the applied cover depth of 10m is reviewed preparing for the worst. <Table 5.28> Thickness review Applied water pressure Applied Thickness of pipe (mm) Applied (kgf/ cm2) cover depth pipe type Diameter (mm) Maximum Maximum (m) Required Nominal (KS) hydrostatic hydrodynamic thickness thickness steel pipe pressure pressure type B D2,000 10.63 5.91 10.00 7.59 15.0 steel pipe type B D1,800 7.49 5.91 10.00 5.77 13.0 steel pipe D1,350 7.67 4.45 10.00 4.69 10.0 type B D600 7.43 6.11 10.00 2.08 6.0 steel pipe type A D350 6.34 5.29 10.00 1.22 6.0 steel pipe type A 5.5.3 Auxiliary facilities (1) Block valve Block valves are installed to flow/block the flow of water in the pipeline, to keep the hydrodynamic pressure in the supply area constant, and to control the water quantity and water pressure. In general, the water supply is cut off if it is necessary to maintain the pipeline or to reduce the affected areas in case of an accident. In this feasibility study, block valves are planned to be installed at major points – starting and end points of the conveyance pipeline, the front and back of the river-, railroad-, or road-crossing points where they are highly likely to cause an accident and deemed difficult to recover in the event of such accident, the front and back of a major device such as flow meter, and a point where drain valves are installed. In addition, block valves are commonly installed about every 1 to 3 km in places in need of ongoing maintenance and management. The minimum number of block valves to be installed is estimated at 2, with 1 valve needed for every 2 km. The required number of block valves are estimated as shown in <Table 5.29>, with the same diameters of the valve and the pipe applied. 5-48

Chapter 5. Conveyance System Planning <Table 5.29> Required number of block valves Classification Diameter(mm) Distance(m) Required number of valves (estimated) Main line Phase 1 Phase 2 Phase 1 Phase 2 Rangkas Bitung branch line Φ2,000 47,925 36,024 26 20 Maja branch line Φ1,800 - 11,901 - 8 Solear branch Parung Panjang Φ600 - 8,560 - 6 branch line Φ350 - 1,200 - 4 Φ1,300 - 4,750 - 5 Φ600 - 4,800 - 5 From the starting point (booster pump station) to the end point (Serpong water treatment plant), the conveyance pipeline branches to four water treatment plants (Rangkas Bitung, Maja, Solear, and Parung Panjang). A branch valve station is installed at the branch point to control and regulate the flow rate. Following the completion of the second phase pipeline, an interconnecting valve will be installed for the integrated operation of the first and second phase pipelines. Like the block valve chamber, the butterfly valve is to be used for the branch valve and interconnecting valve in consideration of the frequency and difficulty of opening and shutting, and the diameter of the valve is the same as that of the pipeline. The installation location of the branch valves and interconnecting valves is shown in <Table 5.30>. <Table 5.30> Installation location of branch and interconnecting valves Classification Measuring No. valves Remarks point Diameter(mm) Branch valve Connecting Phase1 Phase2 valve No.0+0 2,000 1 main line Branch valves No.0+0 600 11 1 Rangkas Bitung and No.14+253 350 11 branch line No.18+582 1,300 11 interconnecting No.30+334 600 11 1 Maja branch valves 1 Solear branch 1 Parung Panjang branch Considering the frequency and difficulty of opening/shutting the valve, the required space for the driving system and operating stroke in the valve station, the butterfly valve type is chosen, the comparison of valve types is shown in <Table 5.31>. 5-49

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia <Table 5.31> Comparison of block valves Classification Gate valve (manual) Butterfly valve (manual) Single disc Double disc Shape Use • anti-leakage for water • flow control for water • for water pipes, pipes and pumping pipes and pumping emergency shutoff for Pros station station water pipes and pumping station Cons Pressure • most widely used • easy to operate • good for anti-leakage property • easy to operate • light in weight and can (two-way leakage Feature • best for anti-leakage be installed in a small protection) • used as subsidiary block space • suitable for high pressure Cost valve in the block valve • low installation cost pipe Choice station • most widely applied • help to avoid shutoff • large-diameter valve is • two-way leakage used as drilling protection with ball valve attachment • better than single disc type • large-diameter valve is • leakage protection is not • relatively heavy in hard to be installed in a as good as double disc weight narrow space because type face to face dimension is • in the case of a large, concentric structure- valve, disc sheet wears down if used for a long period • use within 6, 10kgf/cm2 • use within 10kgf/cm2 • use within 6,10,16kgf/cm2 • valve with D700 and • inexpensive among • more expensive than more is more expensive compared items single type, but less than butterfly valve expensive than ball valve If set at 100% 46% 65% In the KSCS project, pipelines are low pressure and valves serve a function of blocking water flow in an emergency or maintenance, not of controlling water flow. Therefore, the single disc butterfly valve is enough for the job. In the case of special field conditions, a suitable type will be determined when developing a working design. 5-50

Chapter 5. Conveyance System Planning The working torque of the valve is calculated based on the maximum working water pressure to make the opening/shutting speed of each diameter the same. The paint that has good properties and does not affect the quality of water is applied. The seamed pipe is installed in the back of the block valve for an effective maintenance. If the water pressure is high, the resulting frictional resistance may cause difficulty in opening and shutting the valve. Therefore, the subsidiary valve is to be installed for the block valve with the diameter of 400mm and more so that the subsidiary valve helps balance the water pressure before opening the main valve. The access hole will be installed in the front or back of the valve and the air valve will also be installed on the cover of the hole. In addition, the air valve needed to operate the drain valve between block valves will be installed in the front and back of the block valve. This is to reduce the number of air valve stations. The air valve station is planned to be installed on the top of the pipeline, if possible. For the purpose of easy maintenance, block valves are installed in the valve station which has sufficient space. In the valve station, the equipment for drainage and inspection as well as the water pressure gauge to immediately detect abnormal water pressure are to be installed. The valve station is an integrated structure with the valve, which makes its weight large. Therefore, it needs to be installed on firm ground if possible. If it is unavoidable to install the valve station on soft ground or sandy ground vulnerable to liquefaction, there needs to be foundation work or ground improvement. <Figure 5.16> shows an example of the installed block valves and valve station. <Figure 5.16> Installation example of block valves and valve station (2) Expansion pipe The purpose of installing the expansion joint is to absorb differential settlement in soft ground, to deal with the expansion and contraction of the pipeline by temperature (in terms of exposed piping), and to absorb stress such as natural disasters. Therefore, it is necessary to properly arrange telescopic pipes to ensure the safety of the pipeline. <Figure 5.17> shows types of telescopic pipes installed in steel pipes for water works. 5-51

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia <Figure 5.17> Types of telescopic pipes installed in steel pipes for water works The steel pipes buried for water works have a high strength against temperature stress, become a united pipeline connected by welded joints, and have binding force by soil. So, not many expansion joints will be used. Expansion joints are installed in the front and back of block valves, bent pipes, and T-shaped pipes, all of which are vulnerable to temperature stress. The expansion joints are also installed at the terminal connection joints in order to reduce heat stress caused by welding. In this feasibility study, the required quantity of telescopic pipes is planned to be equal to that of block valves and the telescopic pipes are to be installed along with valves in the valve station. The required quantity of telescopic pipes is shown in <Table 5.32>. <Table 5.32> Required quantity of telescopic pipes Distance(m) Required no. of telescopic pipes (estimated) Classification Diameter(mm) Phase 1 Phase 2 Phase 1 Phase 2 Main line Φ2,000 47,925 36,024 26 20 Φ1,800 - 11,901 - 8 Rangkas Bitung Φ600 - 8,560 - 6 branch line Φ350 - 1,200 - 4 Φ1,350 - 4,750 - 5 Maja branch line Φ600 - 4,800 - 5 Solear branch line Parung Panjang branch line 5-52

Chapter 5. Conveyance System Planning (3) Air valve 1) Necessity and required quantity of air valve The purpose of installing air valves is to eliminate or inhale air inside the pipe. At the top of the protrusion on the longitudinal section drawing of the pipeline, an air pocket is formed as air dissolved in water gets released and accumulated. If not removed, the air pocket reduces the cross-sectional area of flow, preventing water from flowing smoothly. It sometimes causes an accident. Therefore, it needs to be removed properly and automatically. When laying pipes or refilling them with water after a suspension of water supply, the air inside the pipe must be eliminated. In a case where water is drained from the pipe during construction or as occasion arises, the inside of the pipe becomes close to vacuum, and then the pipe may be deformed by external pressure. If this is the case, air (gas) must be automatically inhaled to prevent deformation of the pipe. The air valve serves the purpose of eliminating air inside the pipe, so they must be installed in proper places of the pipeline. The air valves are installed at the top of a protrusion on the longitudinal section drawing of the pipeline, where the air is most likely to be gathered. Here, the protrusion is not necessarily the peak point through the entire pipeline, but a local peak near that place. It refers to the top of all the upward protrusion on the longitudinal section drawing of the pipeline. Even if the pipeline is long and there is no protrusion on the longitudinal section drawing, air valves are installed in between block valves so that proper time can be given to refilling and drainage. If the length of the pipeline is long, block valves are installed every 1 to 3km for maintenance. So, air valves must be installed right under the block valve, which is located at the highest location among block valves. <Table 5.33> Diameter and required quantity of air valves Conveyance pipeline Air valve Classification Diameter(mm) Distance(m) Diameter Required quantity Phase 1 Phase 2 (estimated) Phase 1 Phase 2 Main line Φ2,000 47,925 36,024 Φ200 26 20 Φ1,800 - 11,901 Φ200 - 8 Rangkas Bitung branch line Φ600 - 8,560 Φ100 - 6 Maja branch line Φ350 - 1,200 Φ80 - 4 Solear branch line Φ1,300 - 4,750 Φ150 - 5 Parung Panjang Φ600 - 4,800 Φ100 - 5 branch line 5-53

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia Although it is difficult to tell precisely how many air valves are needed at this point in the feasibility study, the required quantity of air valves is expected to be equal to that of block valves, given that the project area sees little change in ground level and the pipeline is a long distance one. The diameter and required number of air valves are shown in <Table 5.33>. 2) Type and diameter of air valve Depending on air release and suction per unit time, air valves are classified into rapid air valve, double air valve, and single air valve. Single air valves are generally used for the pipe less than Φ350mm in diameter whereas rapid and double air valves are used for the pipe more than Φ400mm in diameter. The air suction per unit time is determined by drainage per unit time of the drain pipeline, water quantity in the pipe, and allowable drainage time. The air release per unit time is determined by the supply capacity of the pipe during water filling, safe speed of water filling and allowable water filling time. The applied diameter for double and rapid air valves is shown in <Table 5.34> and the pros and cons of the air valve are summarized in <Table 5.35>. <Table 5.34> Applied diameter of double and rapid air valves Double air valve Single air valve Caliber(mm) Pipe diameter(mm) Caliber(mm) Pipe diameter(mm) Φ80 Φ400 - 600 Φ80 Φ400 - 900 Φ100 Φ600 - 900 Φ100 Φ600 - 1,200 Φ150 Φ900 and more Φ150 Φ900 and more Φ200 Φ1,600 and more Φ200 Φ1,600 and more 3) Block valve for the regulation of air valve The structure of the air valve is simple but its components such as ball and rubber packing are easily damaged, which requires frequent replacement or repair. In order to repair the pipeline without a suspension of water supply, it is necessary to install block valves for the regulation of the air valve between the T-shaped pipe and air valve. 4) Air valve station The air valve station is installed to facilitate the removal of the air and the maintenance of the air valve. In particular, with regard to air valves of the installed pipeline, it is necessary to install an air valve station made of reinforced concrete, which has sufficient space for repair and maintenance work. 5-54

Chapter 5. Conveyance System Planning <Table 5.35> Comparison of air valves Classification Single air valve Double air valve Rapid air valve Shape Structure map Overview • consists of valve body, • consists of valve body, • consists of valve body, float valve, valve seat float valve, valve seat float valve, flow valve Pros base, adjusting screw, base, adjusting screw, guide, flow valve, cone- cone- shaped valve seat, cone- shaped valve seat, shaped valve seat, cover, Cons gasket, ferrule body, cover, valve stem, main strainer Cost gasket, bolt/nut, flange valve body, cap, valve Choice stem packing, valve seat • greater air emissions for • has one air vent, to be depressor its size suitable for small • its small size, light capacity. • has two air vents for weight makes it easy to • its ball valve makes small and large capacity, handle maintenance easy greater air emissions • even for a large • with the valve for diameter, it takes up opening and shutting, small space for maintenance is easy installation ∙strainer prevents foreign • has one air vent, not to be • relatively expensive materials from clogging suitable for large • takes up large space for the pipe capacity. installation • needs to secure some • expensive for its air • its heavy weight makes space for block valves to elimination amount transportation and be installed • vulnerable to leakage handling difficult caused by floating • vulnerable to leakage matters caused by floating matters If set at 100% 152% 63% The Double air valve or Rapid air valve, which have large intake/displacement volume, are generally used for large-diameter pipelines. The Rapid air valve that is more affordable and takes up a little space for installation is recommended. 5-55

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia The valve station is prone to be a rain pool, so it must have a good drainage structure. If the groundwater level near the air valve station is high, the station needs to be installed at the needed height by connecting pipes. This will prevent water from flowing back from the outside. Inside the valve station, the ventilation hole is installed to allow an easy inflow and outflow of air. <Figure 5.18> shows an example of the installation of rapid air valves, which are expected to be used in this project. <Figure 5.18> Installation example of rapid and double air valves rapid air valve double air valve (4) Drain valve 1) Necessity and required quantity of drain valve The purpose of the drain valve is to discharge sludge or sand remaining on the bottom of the pipe when the pipe is laid, to clean the inside the pipe and remove dead water for maintenance in normal times, and to discharge water within a short time in case of emergency. Accordingly, drain valves (sluice valves: plane structure without grooves in the valve disc) are installed at the lowest point on the longitudinal section drawing of the pipeline. The sludge station will also be installed next to the valve station so that the sludge can be discharged to rivers or waterways. It is advisable to install the drain pipes at a place that drains well, if there is one thereabout, even though the pipeline is not particularly situated in the low place. In a case where there is no suitable waterway in the vicinity, it is desirable to lay the drain pipes to the nearest waterway even if the drain pipeline is extended considerably long. Plus, at least one drain valve must be installed in between block valves. Although it is difficult to tell precisely how many drain valves are needed at this point (in the feasibility study), the required quantity of drain valves is expected to be equal to that of block valves, given that the project area sees little change in ground level and the pipeline is a long distance one. The diameter and required number of drain valves are shown in <Table 5.36>. 5-56

Chapter 5. Conveyance System Planning <Table 5.36> Diameter and required quantity of drain valve Conveyance pipeline Drain valve Classification Distance(m) Diameter Required Diameter(mm) quantity Φ500 (estimated) Main line Φ2,000 Phase 1 Phase 2 Φ450 Phase 1 Phase 2 Φ1,800 47,925 36,024 Φ150 26 20 Rangkas Bitung Φ600 Φ100 -8 branch line Φ350 - 11,901 Φ350 Φ1,300 - 8,560 Φ150 -6 Maja branch line Φ600 - 1,200 - 4,750 -4 Solear branch line - 4,800 -5 Parung Panjang -5 branch line 2) Type and diameter of drain valve Since drain valves are not fully opened or shut due to the inflow of sludge and sand, the airtightness of the drain valve when closed may not be sufficient. To address this problem, the soft seal block valve is used, which keeps the airtightness by tightly adhering the rubber molding disc to the surface of the valve. This is also good at stopping the flow in case of overpressure (excessive water pressure). Types of drain valves are compared in <Table 5.37>. The flow velocity of the drain valve needs to be fast enough to properly clean the inside the conveyance pipe, so the diameter of the drain pipe is to be a half (1/2) to one fourth (1/4) of that of the conveyance pipe. The bigger the diameter, the easier the maintenance. In this project, however, there is a possibility that the waterway in the discharge outlet may overflow if the diameter of the drain pipe is Φ500mm and more. In the stage of working design, it is necessary to install multiple facilities for drainage at places where drainage is possible. 3) Installation of drain pipes and drain valve station The invert elevation of the drain pipe should be equal to that of the main pipe. If the discharge surface is higher than the invert elevation, the drain station should be installed between the drain pipe and the discharge outlet. The discharge outlet must be located higher than the high water level of discharge water level to prevent sewage from flowing back into the pipe. 5-57

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia <Table 5.37> Comparison of drain valves Classification Soft seal block valve Block valve for water Stainless block valve works Shape Operation • rubber molding valve • metal-valve disc is • valve disc moves up and principle disc is operated up and operated up and down to down to block flowing down to block flowing block flowing water water Pros water • the groove of the disc in • no need for extra Cons • rubber molding disc the valve body helps keep painting Applied adhered to the valve airtight and safe even diameter of surface has an excellent when excessive water ∙ integrated structure with anti-leakage function pressure occurs disc and stem valve • prone to sedimentation of • Stainless material with Cost • no worry for the foreign substances excellent anti-corrosion Choice sedimentation of foreign • when replacing packing, property helps prevent substances and it can leakage takes place if the corrosion maintain anti-leakage water supply is not • metal sheet may lead to performance suspended. So only when leakage • rubber ring’s airtight there is not water • more expensive than structure does not cause pressure inside the pipe, it other valves spindle to be restraint, is possible to replace the making it easy to operate parts. • relatively heavy in • rubber molding disc weight adhered to the valve • anti-leakage performance surface makes complete is not as good as double cut off possible disc • a concentric circle • a wide array of product structure causes disc specifications sheet to wear and tear if used for a long time • large-diameter valve has a greater surface distance, which requires more space for installation D600mm and less D300 ~ 1,500mm D800mmand less If set at 100% 318% 345% The Soft seal block is chosen to make sure of air tightness. It serves a function of preventing leakage in case that sludge or sand flows in and hinders the valve from opening and shutting completely. 5-58

Chapter 5. Conveyance System Planning <Figure 5.19> Installation example of drain valve (5) Flowmeter 1) Necessity and required quantity of flowmeter Flowmeters are used to measure the amount of raw water used by each water treatment plant. Their measured values are used to identify the water flow rate and to decide charges for raw water used by a water treatment plant. Accordingly, flowmeters are required to maintain a high level of precision. The required quantity of flowmeters is shown in <Table 5.38>. <Table 5.38> Required quantity of flowmeter Classification Diameter of Required no. of Remarks conveyance pipe flowmeter (mm) Phase 1 Phase 2 Inlet of booster pumping station Φ2,200 11 Outlet of booster pumping station Φ2,000 1- Φ1,800 -1 Inlet of Serpong WTP Φ2,000 1- Φ1,800 -1 Rangkas Bitung branch line branch point Φ600 -1 Maja branch line branch point Φ350 -1 Solear branch line branch point Φ1,300 -1 Parung Panjang branch line branch point Φ600 -1 5-59

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia 2) Type of flowmeter There are electronic flowmeters using Faraday’s law of electromagnetic induction, ultrasonic flowmeters using ultrasonic waves, and difference pressure flowmeter using differential pressure generated by fasteners such as venturi pipe and orifice. Electronic and ultrasonic flowmeters are the most widely used ones, and their types are shown in <Table 5.39>. <Table 5.39> Comparison of flowmeters Classification Ultrasonic flowmeter Electronic flowmeter Difference pressure flowmeter Shape Principle • emits the ultrasonic • by applying faraday’s • calculates flow rate by Accuracy vibrator to a fluid and law, it measures measuring the Feature receives the ultrasonic electromotive force difference in pressure Selection waves from the opposite generated by a flowing depending on the size of direction and then fluid and calculate flow flow rate with a device measures the change to rate installed inside the calculate flow rate pipeline within ± 0.5% within ± 0.5% within ± 2.0% • sensor attachment is easy • not influenced by • lacks precision. without contacting fluid, temperature, density, • Abrasion and corrosion viscosity, and mixture. cause a large margin of • by- Pass pipe is not • by- pass pipe is required. error. required. but small- diameter is expensive The Ultrasonic flowmeter that has a high measurement precision and relatively simple structure is chosen. 3) Installation of flowmeter The flowmeter may have a number of problems depending on the installation conditions. It may have a large margin of error if not properly installed. It may be difficult to maintain and manage if there is a puddle of rainwater or groundwater in the flowmeter station. There may be some failures in the devices changing electric signals such as a transmitter or converter. Given all this, it is necessary to pay attention to the installation and environmental conditions of the flowmeter. Good locations to install flowmeters are as follows. An installation example of the flowmeter station is shown in <Figure 5.20>. • a place where it is easy to inspect and read the meter • a clean and dry place where sewage and soil are not invaded • a place where there is little change in pressure • a place where electromagnetic induction failures hardly occur 5-60

Chapter 5. Conveyance System Planning • a place where the ground is not tilted nor soft • a place spacious enough to do replacement, maintenance, and repair work • a place where a sufficient distance for straight pipeline is ensured to prevent vortex from occurring in the front and back of the flowmeter • a place where there is no inflow of air into the flowmeter and where water filling the meter flows. <Figure 5.20> Installation example of flowmeter and flowmeter station (6) Manhole and access hole When installing the conveyance pipes with a diameter of 800mm and more, it is necessary to install manholes. During the construction of the pipeline, manholes are used as an entrance for workers who connect the steel pipes (welders), for materials and equipment, and for forced ventilation while welding or painting. After the construction of the pipeline, manholes are also used for inspection and maintenance. Manholes are generally installed at the bottom of where the air valve is installed, but they are also installed in places where there is a high possibility of an accident like river- and railroad-crossing sections, where topography and geology change, and where the depth of cover is large and the external repair work is not easy. The size of the manhole is usually 600mm. The manhole is made up of a flange cover on the T-shaped pipe that is connected to install the air valve. If the air valve is installed at the top, a nozzle connecting the air valve is attached to the manhole. It is difficult to accurately predict how many manholes will be needed at this point of this feasibility study. Given that the project area sees little change in the ground level and the pipeline is a long distance one, manholes are planned to be installed where the air valves are installed in the conveyance pipeline with a diameter of 800mm and more. As for the conveyance pipeline with a diameter of 800mm and less, access holes will be installed so that a surveillance camera can go to check the condition inside and repair or restoration work can be done during construction as well as maintenance. Access holes are planned to be installed where air valves are installed based on the installation guidelines for the manhole. 5-61

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia The required quantity of manholes and access holes are estimated as shown in <Table 5.40> and their installation example is shown in <Figure 5.21>. <Table 5.40> Diameter and required quantity of manholes and access holes Conveyance pipeline Air valve Manhole/access hole Distance(m) Required no. Required no.(estimated) Dia. Classification Dia. Dia. (estimate) (mm) Phase1 Phase2 Phase1 Phase2 Phase1 Phase2 Remarks Main line Φ2,000 47,925 36,024 Φ200 26 20 Φ600 26 Man- Φ1,800 - 11,901 Φ200 - 8 Φ600 20 - 6 Φ400 Rangkas Φ600 - 8,560 Φ100 - 4 Φ400 hole Bitung Φ350 - 1,200 Φ80 - 5 Φ600 Man- branch line Φ1,300 - 4,750 Φ150 - 5 Φ300 8 Φ600 - 4,800 Φ100 hole Maja branch line access 6 Solear branch line hole Parung access Panjang 4 branch line hole Man- 5 hole access 5 hole <Figure 5.21> Installation example of manhole and access hole manhole cover installation example 5-62

Chapter 5. Conveyance System Planning 5.6 Safety of pumps and conveyance 5.6.1 Cavitation When the head loss increases by the high suction head of the pump, a sudden change in flow velocity, vortex, or failure in the flow path, the pressure inside the pump partially goes below the saturated vapor pressure to generate bubbles. This formation of bubbles is called cavitation. In the pump, cavitation tends <Figure 5.22> Impeller damaged by cavitation to occur at the entrance of the impeller. The bubbles formed by cavitation move with the flow and suddenly collapse once reaching the high pressure section. The repetition of this phenomenon may deteriorate the performance of the pump, entail vibration and noise, and destabilize the operation, which could eventually undermine the pump’s ability. If cavitation is repeated for a long time, the impact accompanied by the burst of the bubble is repeated and damages the material. Accordingly, it is important to take note of the suction conditions of the pump in the design of the pumping station to make sure cavitation does not take place. The installation conditions of the pump suction part are shown in <Figure 5.23>. In <Figure 5.23>, the H.W.L. and M.W.L. stand for high water level and medium water level, respectively, all of which are normal operating levels and serve as standard points for basic hydraulic analysis and calculation. The L.W.L. stands for low water level, or the worst condition for operation during drought season, which is the target level that should be considered in reviewing cavitation. The B.O.T. El. means the bottom elevation of the conveyance tunnel while the G.L. is short for the ground level of the pumping station. The C.O.P. El. Stands for the center of the pipe elevation. (1) Conditions where cavitation does not occur Since cavitation occurs when the pressure of the fluid is less than the saturated vapor pressure, it will be prevented if no part of the pump goes below the saturated vapor pressure. To this end, a Net Positive Suction Head approach is applied to satisfy the following conditions. NPSHav > NPSHreq x 1.3 5-63

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia Here, the NPSHav stands for Available Net Positive Suction Head, or the value determined by the suction conditions of the pump. To put it more concretely, when the pump is installed and used, this value is determined by the pipe or the system of the suction part regardless of the pump itself. The available NPSH is the value obtained by subtracting the saturated vapor pressure of the fluid at the temperature from the absolute pressure that represents the external pressure against the fluid flowing into the center of the suction. The NPSHreq stands for Required Net Positive Suction Head or the head value depressurized at the entrance of the impeller. That is, there is a temporary pressure drop in the fluid flowing into the entrance of the impeller before the pressure is reduced in the impeller, and the corresponding head refers to the NPSHreq. <Figure 5.23> Installation conditions of pump suction Karian Dam Booster Pumping Station H.W.L.(+)67.50 M.W.L.(+)56.43 L.W.L.(+)46.00 G.L.(+) 45.97 BOT El.(+)42.40 C.O.P. El.(+) 42.67 Booster To Pump WTP Bottom El.(+)40.87 (2) NPSHav (Available Net Positive Suction Head) under the installation condition The theoretical formula of NPSHav is as follows: NPSHav = Ha - Hp - Hs – Hf 5-64

Chapter 5. Conveyance System Planning Here, Ha : atmospheric pressure (10.33m) Hp : saturated vapor pressure (0.238m at 20 ℃) Hs : actual suction head (center of pump elevation – low water level) Hf : loss of head in the suction pipeline Since the center of pump elevation, which is needed to calculate the actual suction head of pump, varies from manufacturer to manufacturer, it is estimated at (+)43.0m from the center of pipe elevation (+)42.67. Thus, Hs = 43.0m - 46.0m = -3.0m. The Hf (loss of head) is computed either by quoting from hydraulic calculation or directly calculating from Hazen- Williams Equation. The Hf computed in the hydraulic calculation is 0.095m for the first phase and 0.31m for the second phase. Under the above conditions, the NPSHav is calculated at Phase 1 Hf = 10.33m - 0.238m - (-3.0m) - 0.095m = 12.997m Phase 2 Hf = 10.33m - 0.238m - (-3.0m) - 0.31m = 12.782m Therefore, the NPSHreq to avoid cavitation should be 9.99m for the first phase and 9.83m for the second phase. (3) NPSHreq The NPSHreq has a correlation with pump flowrate (Q), speed of revolution (N), and suction specific speed (S) NPSHreq = [(Q1/2 x N) / S]4/3 The suction specific speed (S) is roughly calculated at 1,200 to 1,300 regardless of the number of revolutions. The flow rate (Q) of the double suction pump is calculated at a half the flow rate. When the pump is operated at 1,450rpm (the number of revolution) with the suction specific speed of 1,200 according to changes in the operating point of the pump, NPSHreq values which are roughly estimated according to the flow rate change, are shown in <Table 5.41>, < Table 5.42> and < Table 5.43>. <Table 5.41> Estimated NPSHreq of the main pump Flow rate ratio 0.8 0.9 1.0 1.1 1.2 36.0 Flow rate Q m3/min 24.0 27.0 30.0 33.0 8.84 NPSHreq M 6.72 7.30 7.83 8.34 5-65

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia <Table 5.42> Estimated NPSHreq of the regulating pump Flow rate ratio 0.8 0.9 1.0 1.1 1.2 18.0 Flow rate Q m3/min 12.0 13.5 15.0 16.5 5.57 NPSHreq m 4.25 4.60 4.93 5.23 <Table 5.43> Estimated NPSHreq of the Rangkas Bitung system pump Flow rate ratio 0.8 0.9 1.0 1.1 1.2 Flow rate Q m3/min 9.6 10.8 12.0 13.2 14.4 NPSHreq m 6.66 3.96 4.25 4.53 4.80 If designed and constructed under the current pump suction conditions, there will be no cavitation in all the main, regulating, and Rangkas Bitung system pumps. 5.6.2 Water hammer analysis (1) Water hammer phenomenon To stop the pump properly, the discharge valve is closed over a certain amount of time so as to prevent against abrupt changes in flow velocity by reducing the discharge amount of the pump. However, if the pump stops when valves are open due to a power outage, the flow rate inside pipes go through dramatic change, leading to sudden surge or drop in pressure. This phenomenon is called water hammer, which may cause damages as described below. • The pump and motor may be counter-rotating due to the backflow of the pressurized flowrate • Increased pressure may cause damages to pumps, valves, flanges, structures, pipelines, and auxiliary facilities • Pipe collapse or rupture occurs if water column separation caused by pressure drop inside the pipe is reunited. • Causes vibration and noise • Abnormal fluctuation in pressure inside pipes makes control devices out of control, making automatic control difficult (2) Input conditions of computational analysis It is difficult to predict if a water hammer phenomenon in the conveyance system is likely to occur. In the past, the simple calculation method using diagrams is used with respect to the simple conveyance system, but now computer analysis driven by a wide range of computer programs makes it easy to predict potential water hammer phenomenon. 5-66

Chapter 5. Conveyance System Planning The Karian – Serpong conveyance pipeline is a very complicated conveyance system with a large diameter including branch lines. If any water hammer accident happens, this could lead to a major catastrophe. Therefore, our team of consultants for this feasibility study conducts a computational analysis to see if the conveyance system would be safe without a water hammer protection device. If it is found that the system is not safe enough, the computational analysis will be carried out on the condition that the water hammer protection device is installed. <Table 5.44> shows basic input conditions for the computational analysis of water hammer. <Table 5.44> Input conditions for computational analysis of water hammer Classification Specification Karian dam H.W.L(+) 67.50m L.W.L(+) 46.0m WTP Serpong WTP Rangkas Bitung WTP H.W.L(+) 53.80m Main pump H.W.L(+) 74.00m Pump Regulating pump phase 1: 60m3/min × 50mH × 7units (1 standby) phase 2: 60 m3/min × 50mH × 6units (1 standby) Booster pump phase 1: 30 m3/min × 50mH × 2units (1 standby) (Rangkas Bitung system) phase 2: 30 m3/min × 50mH × 2units (1 standby) phase 1: 24 m3/min × 52mH × 2units (1 standby) (3) Number of cases for computational analysis The computational analysis of water hammer is carried out under the following 16 scenarios, considering a number of cases – in high or low water level at a dam, with or without water hammer protection device, the first or second phase, and Karian-Serpong or Karian-Rangkas Bitung route. 1) Phase 1 (Karian-Serpong Single pipeline) ① Karian-Serpong route without a protection device at H.W.L. (+)67.5 ② Karian-Serpong route with a protection device at H.W.L. (+)67.5 ③ Karian-Serpong route without a protection device at L.W.L. (+)46.0 ④ Karian-Serpong route with a protection device at L.W.L. (+) 46.0 ⑤ Karian- Rangkas Bitung route without a protection device at H.W.L. (+)67.5 ⑥ Karian-Rangkas Bitung route with a protection device at H.W.L. (+)67.5 ⑦ Karian- Rangkas Bitung route without a protection device at L.W.L. (+)46.0 ⑧ Karian-Rangkas Bitung route with a protection device at L.W.L. (+)46.0 5-67

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia 2) Phase 2 (Karian-Serpong Dual pipeline single hydraulic system) ① Karian-Serpong route without a protection device at H.W.L. (+)67.5 ② Karian-Serpong route with a protection device at H.W.L. (+)67.5 ③ Karian-Serpong route without a protection device at L.W.L. (+)46.0 ④ Karian-Serpong route with a protection device at L.W.L. (+)46.0 ⑤ Karian- Rangkas Bitung route without a protection device at H.W.L. (+)67.5 ⑥ Karian-Rangkas Bitung route with a protection device at H.W.L. (+)67.5 ⑦ Karian- Rangkas Bitung route without a protection device at L.W.L. (+)46.0 ⑧ Karian-Rangkas Bitung route with a protection device at L.W.L. (+)46.0 (4) Water hammer protection device applied in the computational analysis An air chamber, the most stable water hammer protection device, is used in the computational analysis, and the minimum capacity of the air chamber to prevent water hammer phenomenon is selected as shown in <Table 5.45>. <Table 5.45> Specifications of air chamber used in the computational analysis Route Water level Air Chamber Karian-Serpong H.W.L. (+)67.5 Capacity 15.0m3 Karian-Rangkas Bitung L.W.L. (+)46.0 Connected nozzle 350A H.W.L. (+)67.5 L.W.L. (+)46.0 Capacity 15.0m3 Connected nozzle 350A Capacity 15.0m3 Connected nozzle 350A Capacity 15.0m3 Connected nozzle 350A (5) Computational analysis of phase 1 (Karian-Serpong single pipeline) 1) Karian-Serpong route ① Karian-Serpong route without a protection device at H.W.L. (+)67.5 The result of the computational analysis is shown in <Figure 5.24>. Ovals in the figure indicate vacuum generating sections, where the lowest pressure line is less than the facility base line ((-)68.65kPa), thereby leading to water column separation in the pipeline. Therefore, it is necessary to install water hammer protection devices. Oval 1 has the maximum pressure of 456.4kPa and the minimum pressure of (-)93.9kPa. Oval 2 has the maximum pressure of 228.9kPa and the minimum pressure of (-)101.2kPa. 5-68

Chapter 5. Conveyance System Planning <Figure 5.24> Water hammer analysis: H.W.L. (+)67.5, without a protection device, Karian-Serpong route ② Karian-Serpong route with a protection device at high water level of (+)67.5 The result of the computational analysis is shown in <Figure 5.25>. If an air chamber with the capacity of 15m3 is installed, there is no place throughout the entire route where the pressure is lower than the facility base line. Facilities and pipelines are operated stably. <Figure 5.25> Water hammer analysis: H.W.L. (+)67.5, protection device, Karian-Serpong route ③ Karian-Serpong route without a protection device at low water level of (+)46.0 The result of the computational analysis is shown in <Figure 5.26>. Ovals in the figure indicate vacuum generating sections, where the lowest pressure line is less than the facility base line ((-)68.65kPa), thereby leading to water column separation in the pipeline. Therefore, it is necessary to install water hammer protection devices. Oval 1 has the maximum pressure of 990.5kPa and the minimum pressure of (-)101.3kPa. 5-69

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia Oval 2 has the maximum pressure of 369.8kPa and the minimum pressure of (-)101.3kPa. Oval 3 has the maximum pressure of 99.1kPa and the minimum pressure of (-)88.8kPa. Oval 4 has the maximum pressure of 245kPa and the minimum pressure of (-)100.7kPa. Oval 5 has the maximum pressure of 284.3kPa and the minimum pressure of (-)101.3kPa. <Figure 5.26> Water hammer analysis: L.W.L. (+)46.0, no protection device, Karian-Serpong route ④ Karian-Serpong route with a protection device at L.W.L. (+) 46.0 The result of the computational analysis is shown in <Figure 5.27>. If an air chamber with the capacity of 20m3 is installed, there is no place throughout the entire route where the pressure is lower than the facility base line. Facilities and pipelines are operated stably. <Figure 5.27> Water hammer analysis: L.W.L. (+)46.0, protection device, Karian-Serpong route 5-70

Chapter 5. Conveyance System Planning 2) Karian-Rangkas Bitung Route ⑤ Karian- Rangkas Bitung route without a protection device at H.W.L. (+)67.5 The result of the computational analysis is shown in <Figure 5.28>. The oval in the figure indicates vacuum generating sections. Throughout the entire route, the lowest pressure line being less than the facility base line ((-)68.65kPa), thereby leading to water column separation in the pipeline. Therefore, it is necessary to install water hammer protection devices. The oval has the maximum pressure of 1,066kPa and the minimum pressure of (- )101.3kPa. <Figure 5.28> Water hammer analysis: H.W.L. (+)67.5, no protection device, Karian-Rangkas Bitung route ⑥ Karian-Rangkas Bitung route with a protection device at H.W.L. (+)67.5 The result of the computational analysis is shown in <Figure 5.29>. If an air chamber with the capacity of 15m3 is installed, there is no place throughout the entire route where the pressure is lower than the facility base line. Facilities and pipelines are operated stably. <Figure 5.29> Water hammer analysis: H.W.L. (+)67.5, protection device, Karian-Rangkas Bitung route 5-71

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia ⑦ Karian- Rangkas Bitung route without a protection device at L.W.L. (+)46.0 The result of the computational analysis is shown in <Figure 5.30>. The oval in the figure indicates vacuum generating sections. Throughout the entire route, the lowest pressure line being less than the facility base line ((-)68.65kPa), thereby leading to water column separation in the pipeline. Therefore, it is necessary to install water hammer protection devices. The oval has the maximum pressure of 1,590.9kPa and the minimum pressure of (- )101.3kPa. <Figure 5.30> Water hammer analysis: L.W.L. (+)46.0, no protection device, Karian-Rangkas Bitung route ⑧ Karian-Rangkas Bitung route with a protection device at L.W.L. (+)46.0 The result of the computational analysis is shown in <Figure 5.31>. If an air chamber with the capacity of 20m3 is installed, there is no place throughout the entire route where the pressure is lower than the facility base line. Facilities and pipelines are operated stably. <Figure 5.31> Water hammer analysis: L.W.L. (+)46.0, protection device, Karian-Rangkas Bitung route 5-72

Chapter 5. Conveyance System Planning (6) Computational analysis of phase 2 (Karian-Serpong dual pipeline single hydraulic system) 1) Karian-Serpong route ① Karian-Serpong route without a protection device at H.W.L. (+)67.5 The result of the computational analysis is shown in <Figure 5.32>. Ovals in the figure indicate vacuum generating sections, where the lowest pressure line is less than the facility base line ((-)68.65kPa), thereby leading to water column separation in the pipeline. Therefore, it is necessary to install water hammer protection devices. Oval 1 has the maximum pressure of 420.9kPa and the minimum pressure of (-)92.2kPa. Oval 2 has the maximum pressure of 306.1kPa and the minimum pressure of (-)101.3kPa. Oval 3 has the maximum pressure of 227.6kPa and the minimum pressure of (-)101.3kPa. <Figure 5.32> Water hammer analysis: H.W.L. (+)67.5, no protection device, Karian-Serpong route ② Karian-Serpong route with a protection device at H.W.L. (+)67.5 The result of the computational analysis is shown in <Figure 5.33>. If an air chamber with the capacity of 15m3 is installed, there is no place throughout the entire route where the pressure is lower than the facility base line. Facilities and pipelines are operated stably. <Figure 5.33> Water hammer analysis: H.W.L. (+)67.5, protection device, Karian-Serpong route 5-73

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia ③ Karian-Serpong route without a protection device at L.W.L. (+)46.0 The result of the computational analysis is shown in <Figure 5.34>. Ovals in the figure indicate vacuum generating sections, where the lowest pressure line is less than the facility base line ((-)68.65kPa), thereby leading to water column separation in the pipeline. Therefore, it is necessary to install water hammer protection devices. Oval 1 has the maximum pressure of 979.0kPa and the minimum pressure of (-)101.3kPa. Oval 2 has the maximum pressure of 227.58kPa and the minimum pressure of (-)73.8kPa. Oval 3 has the maximum pressure of 245.5kPa and the minimum pressure of (-)101.3kPa. <Figure 5.34> Water hammer analysis: L.W.L. (+)46.0, no protection device, Karian-Serpong route ④ Karian-Serpong route with a protection device at L.W.L. (+)46.0 The result of the computational analysis is shown in <Figure 5.35>. If an air chamber with the capacity of 20m3 is installed, there is no place throughout the entire route where the pressure is lower than the facility base line. Facilities and pipelines are operated stably. <Figure 5.35> Water hammer analysis: L.W.L. (+)46.0, protection device, Karian-Serpong route 5-74

Chapter 5. Conveyance System Planning 2) Karian-Rangkas Bitung route ⑤ Karian- Rangkas Bitung route without a protection device at H.W.L. (+)67.5 The result of the computational analysis is shown in <Figure 5.36>. The oval in the figure indicates vacuum generating sections. Throughout the entire route, the lowest pressure line is less than the facility base line ((-)68.65kPa), thereby leading to water column separation in the pipeline. Therefore, it is necessary to install water hammer protection devices. The oval has the maximum pressure of 1,078.4kPa and the minimum pressure of (-)101.3kPa. <Figure 5.36> Water hammer analysis: H.W.L. (+)67.5, no protection device, Karian- Rangkas Bitung route ⑥ Karian-Rangkas Bitung route with a protection device at H.W.L. (+)67.5 The result of the computational analysis is shown in <Figure 5.37>. If an air chamber with the capacity of 15m3 is installed, there is no place throughout the entire route where the pressure is lower than the facility base line. Facilities and pipelines are operated stably. <Figure 5.37> Water hammer analysis: H.W.L. (+)67.5, protection device, Karian-Rangkas Bitung route 5-75

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia ⑦ Karian- Rangkas Bitung route without a protection device at L.W.L. (+)46.0 The result of the computational analysis is shown in <Figure 5.38>. The oval in the figure indicates vacuum generating sections. Throughout the entire route, the lowest pressure line is less than the facility base line ((-)68.65kPa), thereby leading to water column separation in the pipeline. Therefore, it is necessary to install water hammer protection devices. The oval has the maximum pressure of 1,078.4kPa and the minimum pressure of (-)101.3kPa. <Figure 5.38> Water hammer analysis: L.W.L. (+)46.0, no protection device, Karian- Rangkas Bitung route ⑧ Karian-Rangkas Bitung route with a protection device at L.W.L. (+)46.0 The result of the computational analysis is shown in <Figure 5.39>. If an air chamber with the capacity of 20m3 is installed, there is no place throughout the entire route where the pressure is lower than the facility base line. Facilities and pipelines are operated stably. <Figure 5.39> Water hammer analysis: L.W.L. (+)46.0, protection device, Karian-Rangkas Bitung route Computational analyses of water hammer under 16 scenarios revealed that water hammer occurs if there is no protection device, which leads to a conclusion that an air chamber with the capacity of 20m3 is needed to be installed in the Karian-Serpong and Karian-Rangkas Bitung routes, respectively. 5-76

Chapter 5. Conveyance System Planning 5.7 Pipeline installation 5.7.1 Pipeline installation procedure A field investigation is conducted on the entire route of the conveyance pipeline, and then the location of the pipe installation is determined by taking into consideration the surveyed matters and local conditions. <Table 5.46> shows the procedure of installing steel pipes for waterworks. <Table 5.46> Procedure of installing steel pipes Step Activity Specific work classification Remarks Step 1 Carrying in Steel pipe Valve station, Step 2 Arrangement Pipe components flowmeter station Step 3 Bed excavation Minor transport Step 4 Collapse protection Connected and Premises piping damaged parts Step 5 Drainage Step 6 Welding Piping groundwork Step 7 Electric corrosion Valve station structure prevention Field painting Lifting and steel pipe positioning Welding preparation Cleaning Preliminary welding Inner/outer welding Surface treatment Primary coat Paint over Top coat Visual inspection Step 8 Testing Nondestructive test (welded part) Painting test Step 9 Backfilling Step 10 Commissioning Water pressure test Water flow test 5-77

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia When bringing water pipes to the site, it is necessary ① to use well-organized and fully operational tools because the work involves lifting and unloading of a heavyweight, ② not to give an impact to the steel pipe during the unloading and transportation, ③ to install a support or wedge to make sure the steel pipe does not roll or slide, when installing the pipe, and ④ to check if the painting or lining is damaged. For temporary storage of the steel pipe on the site, it is important to put stoppers on both ends of the pipe to ensure any foreign substance goes into the pipe and it is necessary to put a wedge so that the pipe does not roll. If the steel pipe is to be placed on the site for a long period of time, its inner and outer painting materials may be subject to damage due to the excessive exposure to the sun’s heat. Therefore, it is necessary to take some protective measures to block the heat from the sun. 5.7.2 Welding and joining of steel pipe (1) General aspects Connecting steel pipes in a construction site is essential to maintaining the continuity of the pipeline. Considering that a leakage accident after construction is mostly caused by incomplete connecting parts or joints, it is critical to have precision in welding joints. In this feasibility study, the welding method by diameter, the required number of welding spots, and the weld length are estimated on the assumption that 6m-long steel pipes are used, as shown in <Table 5.47>. The total weld length including the first and second phase reaches about 1,359,539 dia-inch. <Table 5.47> Method of welding and required number of welding spots Conveyance pipeline Steel pipe joint welding Classification Diameter Distance(m) Required No. Weld length (Dia-inch) Welding (mm) phase1 phase2 phase1 phase2 No. phase1 phase2 method Suction pipe Φ3,200 84 - 14 - 128 1,792 - lap Φ2,200 100 - 17 - 88 1,467 - welding Main line Φ2,000 47,925 36,024 7,988 6,004 Φ1,800 - 1,984 80 639,000 480,320 lap Rangkas Φ600 - 11,901 72 - 142,812 welding Bitung branch Φ350 - 8,560 - 1,427 24 - 34,240 lap line welding Φ1,350 Maja branch Φ600 - 1,200 - 200 14 - 2,800 bevel line - 4,750 - butt - 4,800 - welding Solear branch line 792 52 - 41,167 lap welding Parung Panjang branch line 800 24 - 19,200 lap welding Total 642,259 720,539 5-78

Chapter 5. Conveyance System Planning (2) Method of steel pipe joint The methods of steel pipe joint include butt welded joint, lap welded joint, and flange joint. The method must be carefully selected by considering the stability and durability of the welded joints. <Table 5.48> shows the comparison of the joint methods. <Table 5.48> Comparison of welding method Classification Butt welding Lap welding Flange connecting • Plain End: the pipe is cut • One end is built as Bell • Used for conjunctive at right angle End, and the other end as parts (connected to perpendicular to the pipe Spigot End. a field valve) or a place where axis. mainly used for thin welding method that underwater welding is pipe overlaps about 10cm and difficult, or when welds inner/outer surface pipelines are removed • Bevel End: deepens the after temporary use. Connecting molten pool by cutting Flange is packed with method the pipe end in V or X gasket and bolted formation, when Feature sufficient penetration is Opinion not obtained by the plain Choice end welding and fails to be within allowable pressure • Mostly used for small to • Mainly used as a field • Used for valve medium sized pipes (less welding method for large conjunction pipeline of than D500) pipes (more than D600) more than D100mm • Method for steel pipes • Through oxygen • Flange is vulnerable to for water supply, highly compression test, the leakage, so it is not applicable to pipes with tightness of welded parts suitable for main D500mm and less, where on-field can be tested just pipelines, applicable to it is difficult to do inner before refilling valve connecting parts painting • Joints welding: butt welding is applied to pipes with D500mm and less Lap welding is applied to pipes with D600mm and more • Valves connecting: Flange connecting method is applied (3) Method of welded joint The Shielded Metal Arc Welding (SMAW) is a commonly used method of welded joint where inner and outer welding is done manually by welders in a construction site. Thanks to technological progress in the welding electrode and welding technique, the performance of the weld joints is now on par with or even better than the parent material. To avoid safety- related accidents, the Automatic Welding using an automatic molding device is recommended, especially when it is not easy to hire licensed local welders in Indonesia. <Table 5.49> shows the comparison of the SMAW and the Automatic Welding. 5-79

Feasibility Study for Karian – Serpong Raw Water Conveyance System (KSCS), Indonesia An arc welding machine designed to obtain high current with low voltage is divided into direct current and alternating current welding machines. The DC welder has a more complex structure and is more expensive than the AC welder, but due to the arc’s good stability, it is widely used for thin plate welding, CO2 gas welding, and inter gas welding. In contrast, the AC welder is inexpensive and easy to repair, so it is widely used for Submerged Arc Welding (SAW) and SMAW. <Table 5.49> Method of welded joint Classification Manual welding (using arc welder) Automatic welding • Welding is performed manually using • Maintain the pipe’s roundness, arc welder arrangement (piping), and equal spacing, through automatic molding Overview and installation device Construction • Automatic welding with external method automatic welding device and internal Pros automatic welding robot Cons • Inner and outer work done manually on • Preliminary arrangement the site → the roundness adjustment Application (automatic molding) → automatic installation (automatic piping) → external automatic welding → internal automatic welding • There are multiple cases for medium to • Uniform welding quality, fast welding large diameter pipes speed • Allows welding in a narrow space • Multiple application cases • Many construction cases for large diameter pipes (D1,800mm and more) • If pipes are less than D700, inner • Difficult to apply in a narrow place or coating is difficult with obstruction • Quality, constructability, economic feasibility depends on proficiency of a • Has many auxiliary facilities (welding welder (worker) machine, gas container), so it takes • Welding heat may change materials time when the welding location moves. • Cannot conduct quality test on weld zone • Arc welding method is applied when there is a structure in the vicinity or it is difficult to bring an equipment • Automatic welding method is applied to a straight-line section more than a certain length where there is no interference by vertical bent pipe, considering constructability, economic feasibility, and application cases 5-80

Chapter 5. Conveyance System Planning The welding electrode varies according to the type of steel material, the thickness and type of the pipe, and position. The illuminate type electrode and the low hydrogen type electrode are used for Shielded Metal Arc Welding. Using an electrode that is dried well is important because a wet or moist coating material does not only hinder the electrode from working properly but increases the hydrogen content in the welded metal, which may lead to major weld defects including blow hole, pit, and crack. Therefore, it is necessary to dry the electrode well by putting it in the portable dryer for three to four hours of use while making sure that the coating material is not damaged. When the electrode absorbs moisture, have it dried as frequently as possible, and replace it with a freshly dried one. The standards for drying the welding electrode are shown in <Table 5.50>. <Table 5.50> Standards for drying welding electrode Electrode type Condition of electrode Drying Drying temp. time Illuminate type 12 hours passed after drying (opening) or 100 ~ 30 ~ when it is apprehended that the electrode 150 ℃ 60mins. absorbs moisture 30 ~ 60mins. Low hydrogen 4 hours passed after drying (opening) or 300 ~ type when it is apprehended that the electrode 400 ℃ absorbs moisture (4) Method of welded joint The methods of welded joint include butt welded joint and lap welded joint. The butt- welded joint is divided into plain end and bevel end. 1) Butt welded joint ① plain end joint The plain end joint is a method in which the pipe is cut at right angle perpendicular to the pipe axis. It is used when the pipe is thin and has sufficient penetration. <Figure 5.40> Butt welded joint plain end joint V-beveled end joint X-beveled end joint 5-81