5. Material Pipa

1.1.1 Selection of Pipe TypePotential difference between the outlet of the Phase II Sukamaju Reservoir with

furthest off-take point is 160 meter water column while it is zero discharging or static

pressure. So, the pipe material should withstand at least 160 meters water column static

load pressure, water hammer pressure, external load 40 tons/m2 or axle pressure, and

has the resistance to existing soil conditions. Other criteria are pipe lifetime which is

above 50 years, the pipeline class telescope, and comply with the use of standards in

drinking water aspect (SNI, ISO, and AWWA). The advantages and limitations of various

types of pipe materials for the transmission and major distribution of drinking water can be

seen in Table 3-10.

Table 3-1 Type of Pipe ComparisonPipe TypeClassification Coated Steel Pipe Ductile Cast Iron Pipe (DCIP) Polyethylene Pipe Glass Fiber Reinforced Plastic Pipe (GRP)

Type

Outline Pipe made in uncoursed pipe of steel plate coated with coal tar enamel

Steel pipe transformed by adding special elements in the melting state, to improve

strength and heat transfer property

Pipe made from HDPE compound, smooth interior/exterior surface

Composite structure of resin-sand and glass fiber reinforced plastic layer to improve

internal pressure performance.Production Standard D80 - D3,000 mm D80 - D1,20 mm D16 – D2,000 mm D150 - D2,40 mm

Coating Methods Outside : steel pipe + coal tar enamelInside: liquid epoxy resin paint

Outside: carbon, silicon, manganese, phosphor, sulfur | Inside: cement-lining

∙Outside: HDPE resin∙Inside: HDPE resin

∙Outside: glass fiber reinforced plastic ∙Inside: glass fiber reinforced plastic

Specific Gravity 7.75 8.15 Above 0.95 2.0

Water Pressure Test (kg/cm2)

Ø (mm) A B Ø (mm) Type1 Type2 Ø (mm) Water Pressure Ø (mm PN6 PN10

D 350-3,000 25 20Below300 70 60

D150- 2,40012 20

300 - 600 60 50 D16 - 600 40 - 50 PN16 PN25700 - 1,000 50 40 32 50

Weight ∙slightly light (2/3 of DCIP) ∙Heavier than other pipe types ∙slightly light (1/4 of DCIP) ∙slightly light (1/3-1/4 of DCIP)Life Span ∙approx. 50 years ∙approx. 50 years ∙approx. 50 years ∙approx. 50 years

Connection Method ∙welding ∙KP mechanical joint ∙butt fusion ∙coupling

Durability

Corrosionand Chemical

Resistance

excellent corrosion resistance due to coating applied, but probable concerns

in case of coating damaged

similar corrosion behaviour to copper;slower than steel; strong corrosion

&chemical resistance (cement-lining)

∙good corrosion / chemical resistance∙Excellent electrolytic corrosion and

salinity resistance∙good corrosion / chemical resistance

ImpactResistance

∙high intensity and resistance against internal/external pressure and

impact

∙thick and highly intensified but low impact intensity. Potential cracking encountered

when high impact and quick pressure.

∙lower tensile and impact strength than iron pipe, possible to be deformational in poor ground/road for heavy vehicle

∙high hardness and elasticity

Electric Insulation ∙corrosion due to electric insulation ∙corrosion due to electricity generated ∙ anti-corrosion due to insulation material ∙anti-corrosion due to insulation material

Hygienic Aspectshigh possibility contamination ; safe

from external contamination due to high hardness & integrated pipeenabled

∙concerns on possibility of water pollution and damaged scale due to corrosion

∙No release harmful substance including Virtually leak free, not

allow inflow ground water

possible to affect human due to flowing out of glass fiber inside pipes when boring without

water supply suspension

InternalPressure

ImpactResistance ∙good ∙weed ∙good ∙goodWater Pressure 20-25 kg f/cm2 300 mm type 3 pipe :50 kg f/cm2 47-55 kg f/cm2 12-50 kg f/cm2

HydrostaticHead

∙high-pressure pipe : 100m.ordinary pressure pipe : 75 m

high-pressure pipe:100m; ordinary pressure pipe:75m; low-pressure pipe:45m

∙under 300 mm: 75m∙300-600 mm: 100m -

Pressure WaterSupply

∙in case of welded connection, available through high pressure pump; in case of coupling, possible to leak on junction

∙high lift water supply pipe line is not suitable due to possible leakage on

junctions and deviation∙possible to use in the condition of high-

head or through high pressure pump

∙not suitable for high lift water supply pipe line due to possible leakage on junctions

and deviationExternalPressure

Soil PressureRoad Load

strong against external pressure ie. traffic and soil pressure due to steel

∙composed of ferrite, high intensity due to flexible quality of material

∙less intensity than steel piping and weak at external pressure

∙less intensity than steel piping and weak at external pressure

Pipe TypeClassification Coated Steel Pipe Ductile Cast Iron Pipe (DCIP) Polyethylene Pipe Glass Fiber Reinforced Plastic Pipe (GRP)ExternalPressure

FoundationSupporting

∙required for foundation used with good quality sand or earth

∙required for pipe tie ors ladder bars on the soft ground section

∙ required for foundation used with good quality sand or earth

∙ required for foundation used with good quality sand or earth

Contact-Environment

ElectrochemicalCorrosion

welded parts require additional coating / electrochemical prevention; occurrence

∙lower occurrence than steel pipes coated with materials

∙safe against electro-chemical corrosion ∙safe against electro-chemical corrosion

Road-Environment

UndergroundUtilities

∙easy to detour unexpected obstacles due to easy customization of pipes

∙service for other constructions or transfer is difficult due to difficult processability

service for other construction or transfer is difficult due to difficult processability

service for other construction or transfer is difficult due to difficult processability

Trafficprocesses such as payment work could be delayed due to longer construction

period than other pipe types

∙construction period could be reduced more than steel pipes, but it is difficult

due to heavy pipe weight.

Light weight makesinstallation process easy and convenient compare to iron pipe. Butt fusion causes some delay

convenient construction due to light material and easy connection. Cons- truction

periodless than steel & cast iron.

Earthquake GroundDeformation

∙good shock-resistance due to high intensity and high safety

∙possible deviation from connectionwhen earthquake or soft ground settlement.

∙good shock-resistance due to high flexibility and continuity (butt fusion)

possible deviation from connectionwhen earthquake or soft ground settlement

Others DischargeCapacity C = 110 C = 110 C = 130 C = 130

Constructability

∙slightly lighter than cast iron pipes, unfavorable for construction and delivery due to heavier material

∙difficulties in delivery , treatment, and bringing equipment

∙easy to deliver and construct due to light material pipes.

∙easy to deliver and construct due to light material pipes.

∙ difficult for construction of water supply section due to welded connection.

∙easy construction for water supply sections.

Good water tightness by butt fusion, inconvenient due to fusion machine

favorable due to water expansion rubber ring connection

∙less foundation work than other pipe type in case of soft ground

∙no need for expansion joint against temperature change and construction.

∙no need for angle fitting in a small angle areas

∙branch installation by construction method of no suspension of water

supply is relatively difficult.

∙branch installation by construction method of no suspension of water

supply is relatively easy.

∙branch installation by butt fusion and compression saddle without water

supply suspension is relatively easy.

∙construction without water supply suspension is possible but saddle cannot be

used in pressure areas.∙inside welding is impossible for below

D800 mmrelatively less foundation works than

other pipe types in case of soft ground. ∙low leakage by butt fusion

∙anti-corrosion tape finishing is required welding points after welding connection.

∙concern on deviated pipe by uneven settlement in case soft ground.

∙possible to be deformational by compressive strength

∙easy repair but inner coating is not possible after welding for repair.

∙additional protection borehole is required at angle pipe installation points.

easy to manufacture deformed fittings,no need to reinforce for deformed fittings

additional protection borehole is required at angle installation points.

∙no need to protect special pipes due to welding connection.

∙favorable for heavy traffic sections due to convenient construction.

∙unfavorable at traffic congestion area in case of butt fusion

favorable for heavy traffic section due to convenient connection.

Economical efficiency(Price per m)

D 560  : 4,229,094 D 560  : 5,259,818 D 560  : 3,732,156 D 560  : 3,988,772D 700  : 6,249,177 D 700  : 6,864,919 D 700  : 6,704,038 D 700  : 5,307,624D 800  : 7,786,105 D 800  : 8,408,369 D 800  : 8,268,467 D 800  : 6,426,102D 900  : 9,514,299 D 900  : 9,945,678 D 900  : 10,831,866 D 900  : 7,988,993

General Review

∙the safest for leakage due to welding connection. large pipe diameter has economics but small pipe diameter has reduced economics. separated

measures for electro-chemical corrosion is required.

the safest in domestic pipes for external load. Occupies more than 65% of all

domestic water supply pipe, favorable for construction and maintenance with

accumulated expertise. Ease to work in water supply,easy branch pipe installation

excellent chemical stability, corrosion resistance, electrolytic protection.

non-uniform butt fusion can occur water leakage. Suitable for small diameter pipe due to low strength. the larger diameter

of pipe will be less economical

less application history and productivity performance. less reliability on junctions.

impossible production of special pipes including small-sized 80mm and 100 mm

pipe.

Considering the filed conditions whose inner pipe water pressure reaches 160 m, so

in this study GRP pipe is chosen as selected pipe material based on the following

considerations:

- A good resistance to corrosion

- A longtime lifetime

- Low density

- Low leakage level

- Easy and fast in installation