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Comparision UPVC vs. HDPE
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JAMAL PVC PIPE (PVT) LTD
What is PVC? PVC is a cheap vinyl polymer that is used to make pipes. It is the third most popular plastic following polyethylene (PE) and polypropylene (PP). Some of its key features are as follows:
• Lightweight and durable material.
• Low production cost.
• PVC is heavier and stronger in terms of pressure capacity (pipes).
What is High Density Polyethylene?
Also abbreviated as PEHD (Polyethylene High-Density), High Density Polyethylene is a polyethylene thermoplastic that is made from petroleum. HDPE offers more tensile strength, and intermolecular force. Tensile strength measures the force required to pull something apart as applied in wicker strands.
• Resistant to a variety of chemical solvents.
• Lighter, stronger, harder, and can withstand higher temperatures.
• Can withstand temperatures of 230 degrees Fahrenheit.
• Has absorptive characteristic that dampens vibrations.
• Has a higher Crystallinity than Polypropylene. Crystallinity influences hardness and density, hence the name High Density Polyethylene.
• Polyethylene is the most widely used plastic. Eco-friendly material that can be recycled!
• Used to make fireworks, wood plastic composites, water pipes.
HDPE is made from the catalytic polymerization of ethylene. Polymerization is achieved through suspension, gas, or solution-phase reactors. Comonomers (butane, octane, and hexane) are added to increase intermolecular force.
Summary:
1. Polyvinyl chloride (PVC) is a cheap and durable vinyl polymer used in construction
projects while high density polyethylene (HDPE) is a polyethylene thermoplastic that is
made from petroleum.
2. Polyvinyl chloride is the third most widely used plastic while polyethylene of which HDPE
is a type is the most widely used plastic.
3. PVC is amorphous while HDPE is semi-crystalline.
4. Both are strong and durable, but their strengths vary and they have different
applications. PVC is heavier and stronger while HDPE is harder and more abrasion and
heat resistant.
5. HDPE pipes are found to be able to dampen and absorb shock waves minimizing surges
that can affect the system while PVC cannot.
6. HDPE is more suitable for lower pressure installations while PVC is more suitable for
direct burial and trenchless installations.
JAMAL HDPE Pipes for Submarine & Underwater Pipeline Pipeline effluent, marine outfalls, Salt-water intake lines, Rivers/ Canal crossing under water. Advantages: Superior corrosion resistance, Superior wear resistance, Chemical resistance, Light Weight and Better impact.
MAJOR ADVANTAGES OF “JAMAL” HDPE PIPES.
• Corrosion resistance • Chemical resistance • Non toxic • Long life • Durability • Impact Strength • Light Weight • Lower Installation cost • Easy Flow • Easy & Economical transportation
PVC Pipes
Applications of PVC pipes
• Agriculture • Aquaculture • Telecommunication • Building construction • Potable water supply and distribution system • Industrial water/chemical circulation system • Irrigation project • Hand pump • Jet pump • Dairies • Bio gas, natural gas and oil distribution lines • Air Ducting • And others
Merits of PVC
• Economical in handling & transportation costs • Self fits sockets are shaped with high precision on specially developed sophisticated machines • Installation is easier as compared to plain ended pipes and loose couplers • The number of joints is reduced by 50% resulting in substantial reduction of labor costs • Less friction loss, saving on pumping costs (Energy saving) • Better flow and more discharge of water • Longer existence of the pipe, low maintenance and replacement cost • Uniform flow of water throughout & no menace of contamination due to deposits • Reduces installation cost and saves time. • Greater cutback in material cost • Non toxic in nature • Pipes are accessible in metric series in a standard length of 6 meters. These pipes are joined using
solvent cement in which mating and fusion between pipe & fitting takes place creating a homogeneous joint.
• The strong solvent cement joint is enduring and trouble free • Their main application is agriculture i.e. for water supply, drip irrigation & sprinkler lines etc., as well
as for drinking water allocation. However, these can also be used in cables ducting, ventilation pipe lines and slurry lines etc.
Features
• UV stabilized • Assured supply of dirt free with odorless transporting potable hygienic water as they are not subject
to contagion • Economical, low operating and easy for continuance with cost effective • No root penetration of any flora • Long lasting – PVC is free from scale formation, rusting, weathering & chemical action, which makes
PVC more durable for rated working condition • No deposition, no reduction in bore size • Mirror smooth inside surface defines high flow rates • Light weight offers total economy in handling, transportation and prompt installation • Easy to join as there is no complicity due to non use of solvent cement • Unaffected by termites, fungus or bacteria and free from algae formation • Seamless, strong, resilient longer life • Well acknowledged by construction industry and others in national and international market • Wall thickness and weight as per standards • Filler content as per norms • Latest technology in compounding and pipe extrusion
Pressure Class Comparison for PVC and HDPE Pipes as a
Function of Flow Velocity of Water
240
220
200 PVC - DR 18 - Pressure Class 150
180
[psi
] 160
140
Clas
s
120
Pres
sure
100
80
60
40 HDPE - DR 17 - Pressure Class 100
20
0
0 1 2 3 4 5 6 7 8 9 10
Water Flow Velocity [fps] PVC - DR 18 HDPE - DR 17
When comparing differences in a materials performance characteristics, such as between HDPE and PVC, it is important to make sure that you are making an accurate and equal comparison of the same characteristic exhibited in an identical situation. The following graphs are used to show the differences found in the pressure class performance exhibited by HDPE SDR 17 and PVC DR 18 in relation to a common occurrence found in all water distribution systems; that being fluctuations (many time sudden and sig-nificant) in the flow velocity of water. In the following graphs, the BLUE LINE will depict PVC DR 18 Pressure Class 150 pipe and the ORANGE LINE will depict HDPE SDR 17 Pressure Rated for 100 psi operations. It is important for us to note and to understand from the beginning of this comparison that the term PRESSURE CLASS does not - and never has had the same performance definition for HDPE as it does for PVC. For the purpose of providing an equitable comparison we will be referring to the WORKING PRESSURE RATING** of each material in an identical system scenario. ** NOTE
In the most general sense, the WORKING PRESSURE RATING is the maxi-mum pressure you can put a thermoplastic pipe (amorphous and semi-crystal-line) under all normal operating conditions and expect no ruptures during its service life (I.e. field pressure rating, not laboratory).
Pressure Class Comparison for PVC and HDPE Pipes as a Function of Flow Velocity of Water
240 220 PVC DR 18 - Pressure Class 150 Maximum Surge Capacity 188 psi
200 (Operating Pressure + Surge Pressure) 180
The surge potential for a 2 fps change in flow velocity = 38 psi
Pre
ssur
e C
lass
[psi
]
160 140 120 100
80
60
40
T
(PR) @ 0 fps i n h e W o
r
rki
de si el ati
g n o n
lif
e.
Maximum Operating Pressure 150 psi @ 2 fps (WPR)
188 (Max Design Pressure) - 38 (2 fps Surge Potential)
150 (Pressure Class & Max
(1 fps = approx. 19 psi based on a non-linear scale)
n
g
P
t r
es s o
fl u o r e
w v (Ma
el xi
ocit mu m
y ch a Al
n l
g es o w abl
i e
O
n ord e per
r f a t i
or ng
P P r
VC es to s
ur e) m
mai n u s
t t ai b
n i t e v ari
s mi e d ni
m u
m
20 Operating Pressure)
0 0 1 2 3 4 5 6 7 8 9 10
Water Flow Velocity [fps] PVC - DR 18
The operational limits of PVC are categorized in terms of PRESSURE CLASS. The term PRESSURE CLASS indicates the pipe’s maximum allowable operating pressure(alsoknown as it’s maximum working pressure rating “WPR”) and is based on the PVC’spressure rating (maximum operating pressure @ 0 fps with no allowance for surge ) minus a surge potential that is calculated from a baseline flow velocity of 2 fps . EXAMPLE: PVC - DR 18 - Pressure Class 150 has a long term fatigue service life based on a zero velocity total pressure capacity of 188 psi. It has a maximum allowable operating pres-sure (WP) of 150 psi with a surge allowance of 38 psi based on a 2 fps flow velocity.
188 (PR) - 38 (Ps) = 150 (WP) = 150 PC The Pressure Class for a PVC pipe is directly related to the pipes specific DR. The ridged PVC material can only accommodate anticipated pressure surges by de-rating the maximum allowable operating pressure (Working Pressure) in direct proportion to any changes experi-enced in system flow velocities. As flow velocities increase more of the PVC pressure capacity is consumed by surge pressure. Surge pressures are a result of changes in flow velocity and are approx. 19 psi per every 1 fps change in a DR 18 PVC pipe. Any increases in flow velocity will require a reduction in the allowable operating pressure (working pressure) in order to ensure that the surge capacity of the material will not be exceeded and the long term fatigue service life will not be reduced.
Pressure Class Comparison for PVC and HDPE Pipes as a Function of Flow Velocity of Water
240
HDPE DR 17 - Pressure Class 100 Maximum Max Surge Capacity 200 psi 220 200 180 160
(Operating Pressure + Surge Pressure)
Pre
ssur
e C
lass
[psi
]
140
The Working Pressure (Constant Allowable Operating Pressure) does not need to be varied in
120
relation to flow velocity changes in order for HDPE to achieve its minimum design life.
100
80
(PR) is determined by a calculation 100 (Pressure Class & Constant
60 based on the Pipe DR and the HDS Operating Pressure)
with a typical safety factor of 2.
40 + 100 (200% Safety Factor )
20
200 (Max Pressure)
0
0 1 2 3 4 5 6 7 8 9 10
Water Flow Velocity [fps] HDPE - DR 17
Due to the significant material differences and performance characteristics found in PVC and HDPE, the term PRESSURE CLASS has no equivalent definition that effectively links the two materials together. Today, when looking to implement the use of HDPE based on an equivalent PVC Pressure Class, it is imperative that you know beforehand what the range of your WORKING PRESSURES (operational pressures) will be and then you need to match your systems specific operational needs to the performance characteristics of the HDPE’s SDR which is typically categorized as the PRESSURE RATING. HDPE’s PRESSURE RATING is based on its maximum allowable operating pressure and it indicates the upper limit of the pipe’s constant operating pressure(alsoknown as it’s working pressure rating “WPR
”.This PRESSURE RATING not onlyidentifies the constant and sustainable operating pressure that does not have to bechanged or reduced in relation to changes in the flow velocity of water; it also in-cludes the pipes ability to accommodate an infinite number of anticipated pressure surges at 150% of its stated operating pressure in addition to accommodating a highly significant number of pressure surges at 200% of its stated operating pressure.
EXAMPLE:
50 (50% of PR) 150 psi (for infinite surges) 100 (PR) + =
100 (100% of PR) 200 psi (for occasional surges)
Pressure Class Comparison for PVC and HDPE Pipes as a Function of Flow Velocity of Water
240
220
200
180
[psi
] 160
140
Clas
s
120
Pres
sure
100
80
Area Where HDPE & PVC
60
Perform Equally
40 In a system with a Working Pressure
20 (Operating Pressure) up to 100 psi and
0
a water velocity of 5 fps or less
0 1 2 3 4 5 6 7 8 9 10
Water Flow Velocity [fps] PVC - DR 18 HDPE - DR 17
Having distinguished the differences in the terms “PRESSURE CLASS” and “PRESSURE RATING”as it is used for PVC and HDPE, and having defined some of the performance limitations associated with the interpreta-tions of those terms; we will now look at some of the implications of the two materials using a comparative scenario based on the parameters estab-lished by each of the materials related pressure class and pressure rating. The first area we will notice is an area where both materials function equally DR for DR. The light blue area highlighted in this chart identifies the specific operational range found within a distribution system where HDPE SDR 17 pressure class 100 and PVC DR 18 pressure class 150 will perform equally well. You will note that within this area the operating pressures (working pressures) do not exceed 100 psi and the flow veloci-ties do not exceed 5 fps.
Pressure Class Comparison for PVC and HDPE Pipes as a Function of Flow Velocity of Water
240
220
200
180
[psi
] 160
140
Cla
ss
120 Area Where Static Strength
Pres
sure
of PVC is Superior to HDPE
100
80
Area Where HDPE & PVC
60
Per form Equally
40 In a system with a Working Pressure
20 (Operating Pressure) up to 100 psi and
0
a water velocity of 5 fps or less
0 1 2 3 4 5 6 7 8 9 10
Water Flow Velocity [fps] PVC - DR 18 HDPE - DR 17
In this chart we are able to identify a small area where the STATICSTRENGTH
of the PVC (due to its higher hoop-stress capability) is actuallysuperior to the HDPE. It must be noted however that we are talking specifically about static strength not dynamic strength. The ridged material characteristic of an amorphous plastic such as PVC makes it an ideal choice for pressure containment systems as long as the system will not
experience any dynamic changes or cyclic events (pumps turning on and off - water hammer - etc.) within the system. The trade off for having a greater static strength however, is a significant reduction in the fatigue or cyclic resistance of the material. It is for this reason that the maximum operating pressure of an amorphous plastic such as PVC must be de-rated in relation to the flow veloci-ties it will experience. The surge pressures experienced within a closed system that are associated with sudden or cyclic changes in flow velocity will:
a) quickly subject the material to pressures beyond its capacity (short term result), or b) bring the material to its point of fatigue failure (long term result)
Pressure Class Comparison for PVC and HDPE Pipes as a Function of Flow Velocity of Water
240
220
200
180
[psi
] 160 HDPE DR 17
140
s
Area Where Static Strength
Safe Area For Infinite Recur r ing Surges
120 (0 fps - 4.7 fps)
Pres
sure
of PVC is Superior to HDPE
100
80
Area Where HDPE & PVC
60
Per form Equally
40 In a system with a Working Pressure
20 (Operating Pressure) up to 100 psi and
0
a water velocity of 5 fps or less
0 1 2 3 4 5 6 7 8 9 10
Water Flow Velocity [fps] PVC - DR 18 HDPE - DR 17
In this chart we begin to see that the flexible, semi-crystalline material characteristic of HDPE exhibits a higher capacity for tolerating surge pressures. This is due to the materials interconnected and entangled molecular structure. The unique performance characteristic of the HDPE polymer chains disentangling (flexing) under sudden stress and then returning to its normal state, provides the HDPE with the ability to absorb some of the energy generated by the pressure surge. This inherent mechanism provides the HDPE with a built in safety factor for surge stresses. As we can see in this graph, up to 150% of the HDPE’s Pressure Rating (PR) is safe for an infinite number of cycles This gives HDPE a unique operational area (indicated by the darker blue area) that allows for the working pressure in a HDPE system to remain constant and unchanged at flow velocities of 5 fps and lower with no de-rating required.
Pressure Class Comparison for PVC and HDPE Pipes as a Function of Flow Velocity of Water
240
220 PVC DR 18 - Pressure Class 150 design Max 188 psi
200 (Operating Pressure + Surge Pressure)
180
[psi
] 160
140
Cla
ss
120 Area Where Static Strength HDPE DR 17
Pre
ssur
e of PVC is Superior to HDPE Safe Area For Infinite Recur r ing Surges
100
(0 fps - 4.7 fps)
80
Area Where HDPE & PVC
60
PVC DR 18
Per form Equally
40 In a system with a Working Pressure Must Be De-Rated To
Accommodate Operating
(Operating Pressure) up to 100 psi and
20 Pressures In Relation To Flow
0 a water velocity of 5 fps or less Velocities Above 5 fps
0 1 2 3 4 5 6 7 8 9 10
Water Flow Velocity [fps] PVC - DR 18 HDPE - DR 17
We all know that in the “real world” most systems are going to experience flow ve-locities that exceed 5 fps. That requires a closer look at the dynamic effect that changes in flow velocity will have on the different pipe materials. We stated earlier that as flow velocities increase, the maximum allowable operating pressure (working pressure) in a PVC system must be de-rated in direct proportion to the flow velocity change. This critical area is highlighted in red and as can be seen, the maximum allowable working pressure must be significantly reduced in order to accommodate the increases in surge pressure. This de-rating and reduction of work-ing pressure must be done so that the maximum working pressure + pressure surge, will not exceed the surge capacity of the pipe system (indicated by dotted green line) and compromise both the systems overall integrity and cause a reduction in the PVC’s fatigue life cycle. Pressures that go beyond this limit indicated by the green line ex-ceed system limits as defined by the AWWA for PVC pipe. (The fatigue life of PVC pipe is not all inclusive. It must be calculated for each DR using a specific
flow velocity, at a specific static pressure (hoop stress). In the case of DR 18 PC150 - the fatigue life of the PVC pipe is determined to be able to withstand 48,965 surge events before material failure takes place. This equates to 2 surge events per day for 50 years or 6 surge events per hour for 15 years).
[2 cycles = 1 Surge Event , 97,890 cycles = 48,945 surge events]
Pressure Class Comparison for PVC and HDPE Pipes as a Function of Flow Velocity of Water
[psi
]
240
220
200
HDPE DR 17 - Safe Area For Occasional Surges 4.8 fps - 10 fps
180
(> 10 million cycles or 6 cycles per hour for 190 years)
160
HDPE DR 17
140
Area Where Static Strength
Safe Area For Infinite Recur r ing Surges
120 (0 fps - 4.7 fps)
of PVC is Superior to HDPE
100
80
Area Where HDPE & PVC 60
Per form Equally
PVC DR 18
40 In a system with a Working Pressure Must Be De-Rated To
Accommodate Operating
(Operating Pressure) up to 100 psi and
20
Pressures In Relation To Flow
0
a water velocity of 5 fps or less
Velocities Above 5 fps
0 1 2 3 4 5 6 7 8 9 10
Water Flow Velocity [fps]
PVC - DR 18
HDPE - DR 17
Once again, even with flow velocities exceeding 5fps, the unique performance characteristics of HDPE exhibit a higher tolerance for resisting surge pressures. An additional inherent safety factor up to 200% of its Pressure Rating (PR), gives HDPE a unique safety area (indicated by the yellow area) that allows for the operating pressure in a HDPE system to remain constant and unchanged at flow velocities between 5 fps and 10 fps still with no de-rating required. All the while maintaining the capability of accepting and resisting a finite yet highly significant number of occasional cyclic events, surge events or sudden changes in pressure without having any impact on the long term performance of the pipe material (Like PVC, the fatigue life of HDPE pipe is not all inclusive. It must be calculated for each DR using a specific flow velocity, at a specific static pressure (hoop stress). In the case of SDR 17 - the fatigue life of the HDPE pipe is determined to be able to withstand > 5 million surge events which is equivalent to about 273 surge events per day - or 11 surge events per hour for 50 years - or 6 events per hour for > 190 years.)
[2 cycles = 1 Surge Event, 10 million cycles = 5 million surge events]
Pressure Class Comparison for PVC and HDPE Pipes as a Function of Flow Velocity of Water
240
220
200
180
[psi
] 160 Area where HDPE is super ior to PVC
140
Cla
ss
120 Area Where Static Strength of
PVC is Superior to HDPE
Pre
ssur
e
100
80
Area Where HDPE & PVC
60
PVC DR 18
Per form Equally
40 In a system with a Working Pressure Must Be De-Rated To
Accommodate Operating
(Operating Pressure) up to 100 psi and
20 Pressures In Relation To Flow
0 a water velocity of 5 fps or less Velocities Above 5 fps
0 1 2 3 4 5 6 7 8 9 10
Water Flow Velocity [fps] PVC - DR 18 HDPE - DR 17
As you can see by the area highlighted in green, what we have is a significant area where DR for DR, the performance capabilities of the HDPE are clearly superior to those of the PVC.
Pressure Surge in DR 18 PVC System (Operating at 80 psi @ 8 fps)
Pre
ssur
e C
lass
[psi
] 240
220 Pressures above the green line exceed AWWA limits for 221 psi
200 PVC pipe according to AWWA C900 & AWWA M23. (WP + PS)
180
160 141 psi
140 ( PS)
PVC
120 PC 150
100
80 80 psi
60 (WP )
Maximum Allowable Operating Pressureshould not exceed 47
psi
40
20
0
0 1 2 3 4 5 6 7 8 9 10
Water Flow Velocity [fps] PVC - DR 18
Pressure Surge in SDR 17 HDPE System Operating at 80 psi @ 8 fps
240 185 psi
220 (WP + PS)
200 Safe Area For Occasional Surges 4.8 fps - 10 fps
180 (> 10 million cycles or 6 cycles per hour for 190 years)
[psi
] 160
140 85 psi
Cla
ss
Safe Area For Infinite Recurr ing Surges
( PS)
120 (0 fps - 4.7 fps)
Pre
ssur
e
100
80 80 psi
(WP )
60 HDPE
40 PR 100
Operating Pressure does not need to be de-rated!
20
0
0 1 2 3 4 5 6 7 8 9 10 Water Flow Velocity [fps]
HDPE - DR 17
HDPE SDR 17 PVC DR 18
@ 80 psi @ 10 fps @ 80 psi @ 10 fps
•Semi-Crystalline Thermoplastic •Amorphous Thermoplastic
•Pressure Rating - 100 psi •Pressure Rating @ 0fps (no surge allowance) - 188 psi
•Pressure Class - 100 •Pressure Class - 150
•Working Pressure Rating - 100 psi •Wor king Pressure Rating - 150 psi @ 2 fps
(remains constant no de-rating required) WP must be decreased to no more than 47 psi because the
flow velocity is at 8fps otherwise the surge capacity will
be exceeded i.e. (WP) 47 + (Ps) 141 = 188 psi
•Surge Capacity - 200 psi Total (WP + •Surge Capacity - 188 psi Total (WP + Ps)
– 50% of Pressure Rating for Infinite Surges, or (WP) 80 + (Ps) 141 = 221
– 100% of Pressure Rating for Occasional Surges The PVC Prssure Class 150 Surge Capacity in
(WP) 80 + (Ps) 85 = 185 psi this scenar io is exceeded by 33 psi according to
This falls comfor tably within the HDPE Pressure AWWA C900 & AWWA M23
•Cyclic Resistance** to mater ial failure
Class 100’s “Safe for Occasional Surge “ zone.
•Cyclic Resistance to mater ial failure** 48,945 events, or
2 events per day for 50 years, or
>10 million events, or 6 events per hour for 15 years
273 events per day for 50 years, or (assuming WP is cor r ectly adjusted with flow velocity
11 events per hour for 50 years, or
changes otherwise these figures will be significantly
6 events per hour for >190 years r educed)
•Method of Joining - Heat Fusion •Method of Joining - Gasketed - Push On
•Type of Restr aints - N/A in totally fused system •Type of Restr aints - Bolt on, or Thrust Blocks
Comparison of PVC and HDPE
Material Properties of PVC and HDPE
The material properties of PVC make PVC a better choice than HDPE for many applications. The following table lists the properties for both PVC and HDPE that are most important to the design of piping systems:
Property Specification PVC HDPE
3408/36081 HDPE 47102
Tensile Strength (PSI) ASTM D638 7,000 3,200 3,500
Specific Gravity ASTM D1505
1.40 0.95 0.94
ASTM D3350 Cell Class ASTM D3350
NA3 345464 445574
Hydrostatic Design Basis @73° F (PSI) ASTM D2837
4,000 1,600 1,600
Modulus of Elasticity - Short Term (PSI)
ASTM D638 400,000 110,0004 110,0004
Hardness (Rockwell R) ASTM D785 117 52 NA
Coefficient of Linear Expansion (in./in.°F)
ASTM D696 0.30 x10-4 (0.36"/100'/10°F)
1.2x10-4 (1.44"/100'/10°F)
1.2x10-4 (1.44"/100'/10°F)
Water Disinfectant Induced Oxidation5 - Highly Resistant Low Resistance Low Resistance
Hydrocarbon Permeation6 - Highly Resistant Highly Permeable
Highly Permeable
Pressure Class Comparison
PVC HDPE
Dimension Ratio Pressure Rating Dimension Ratio Pressure Rating
DR 18 235 PSI DR 7.3 255 PSI
DR 21 200 PSI DR 9 200 PSI
DR 25 165 PSI DR 11 160 PSI
DR 32.5 125 PSI DR 13.5 130 PSI
DR 41 100 PSI DR 17 100 PSI
DR 51 80 PSI DR 21 80 PSI
Comparison BetweenHDPE and u-PVC Pipes:
Particulars HDPE PVC Remarks
Density (gm/cc) 0.945 -0.956 1.40 - 1.46 Easy handling
Flexibility High Rigid (no flexibility) Easy laying
Length 6m,12 m,50m, 100m, 300m,500m or (as per
4 or 6m HDPE more suitable for continuous and cost effective
Trench Not needed Needed Lower installation cost
UV stability Excellent Moderate Better life
Continuous use - 50° C - 80° C -5 - 60° C - temperature Vicat softening 125° C 80° C - temperature Decomposition 360° C 160° C - temperature Impact Strength Excellent Good -
Chemical
Very good Good -
Surge pressure High Moderate -
Power cost Low Higher than HDPE Saves energy
Reuse of pipes Easy Inconvenient
Installation Easy and quick Requires extra skill and time Saves time and money
Jointing
No Chance of waste and no need sockets for jointing
Requires extra skill and approx.14” length waste due to over lapping and also need sockets.
Comparison BetweenHDPE and G.I Pipes:
Parameter HDPE G.I
Length HDPE pipes are flexible and can be coiled. User gets single pipe as per his requirements. Hence no/ less joints. Coils are available in different lengths.
GI pipes are available in 6 m length. Threading is required to join pipes which is laborious, expensive and time consuming.
Size and Pressure Wide range from 20mm to 630mm sizes with2.5 to 16 kg/cm² pressure rating.
Limited range compared to HDPE pipes. They are available in 8-100 mm dia.
Corrosion Possesses excellent corrosion resistance to water, acids &alkalies.
Corrodes faster specially in water submergence.
Internal Surface Smooth surface offers very low frictional resistance. Resistance to encrustation/ abrasion.
Offers resistance to flow due to less smoother surface which gets worse due to corrosion over a period of time.
Flexibility Can take curvature up to a radius 25 times the pipe dia. hence can be coiled.
No flexibility. Can be used in straight length.
Weight It is approx. 4 to 5 times lighter then GI pipes for applications like suction & delivery pipes.
Heavier than HDPE pipe, so it is costly is transportation, installation & manpower.
Maintenance & Life
Virtually maintenance free. The joints are100% leak proof. Have a long life.
Requires maintenance frequently. Life is not more than five years.
Installation Easy, as no special equipment’s are required. Submersible pump can be installed in 1 hour time for depth more than 80m to 100m.
Cumbersome. Chain pulley required apart from holding clamps. Takes almost 5 to 8 hours depth of 80m to 100m.
Cost Unit cost of delivered water is approx. 15 to20% lower than GI Upto110 mm size
Unit cost of delivered water is more in GIpipes as compared to HDPE pipes.
Comparison between HDPE PVC A.C AND G.I pipes:
DESCRIPTION HDPE PIPE PVC PIPE AC PIPE STEEL PIPE
PIPE WEIGHT LIGHT LIGHT 2-3 TIMES OF HDPE PIPE AND PVC PIPE
5 TIMES OF HDPE PIPE AND PVC PIPE
TRANSPORTATION • EASY FOR DELIVERY AND HANDLING
• CAN INSERT SMALL SIZE IN BIG SIZE PIPE
• PIPE OUTSIDE DIMETER UPTO 110 MM. CAN BE COILED
SAME AS HDPE PIPE BUT CANNOT BE DELIVERED IN COIL
REQUIRE SPECIAL PREPARATION AND TAKING CARE IN TRANSPORTATION
HEAVY WEIGHT, NEED HEAVY EQUIPMENT FOR LOADING AND UNLOADING
FLEXIBILITY 25-40 TIMES OF OUTSIDE DIAMETER
CANNOT CANNOT CANNOT
FLOW PROPERTY C = 150 C = 150 C = 100 C = 100
SPEED OF PRESSURE WAVE IN PIPE
200 - 400 M/SEC 200 - 400 M/SEC
600 - 800 M/SEC 1,000 - 1,200 M/SEC
MAXIMUM WORKING PRESSURE
25 bar 13.5 bar 25 bar 50 bar
WORKING TEMPERATURE
- 40°C TO 80 °C 0°C TO 60 °C 30°C TO 45 °C -100°C TO 300 °C
SERVICE LIFE MORE THAN 50 YEARS
10 - 20 YEARS 10 - 20 YEARS 10 - 30 YEARS
INNER SURFACE NO CORROSION, NO CALCIUM CARBONATE DEPOSITS
SAME AS HDPE PIPE
WATER ABSORBTION = 20%, CAN FORM CALCIUM CARBONATE DEPOSITS
CORROSION, CAN FORM CALCIUM CARBONATE DEPOSITS
Price Comparison BetweenHDPE PVC A.C AND G.I
Market Price of Pipe (Rs/Meter)
CHEMICAL RESISTANCE
HIGH RESISTANT TO ACID AND BASE
ALMOST SAME AS HDPE PIPE BUT CANNOT RESIST TO SOME SOLUTIONS
NON RESISTANT NON RESISTANT
UNDERGROUND INSTALLATION
WELDING ON GROUND AND LAYING INTO TRENCH
JOINTING IN TRENCH
NEED HEAVY EQUIPMENT FOR JOINTING, WIDER TRENCH IS REQUIRED (JOINTING IN TRENCH)
SAME AS AC PIPE
COST OF TRANSPORTATION AND WELDING COMPARE WITH PIPE COST
10% 10% 30% (NOT INCLUDE COST OF DAMAGE FROM PIPE BROKEN)
30%
Size HDPE U- PVC A.C G.I
3” 242 245 370 790
6” 765 795 1015 2210
Comparison between GRP and PE Weholite pipes in DN 3000 mm.