Poliplex PE100 Pipe
Polyethylene (PE) pipes have been produced in Australia since the mid 1950’s, whilst initially in smaller diameters for industrial and agricultural applications, PE pipe and fittings are now available in diameters up to 2000mm. Usage has grown rapidly over this period and polyethylene resins are evolving from the tradition PE100 from the growing demand for higher performance, longer-life PE pipes that will provide reliable service for 100 years or more.
POLIplex® pipes are used to convey all types of liquids and gases for above and below ground applications including:
- Urban water and gas supply
- Mine dewatering
- Irrigation supply
- Slurry pipelines
- Vacuum, pressure and gravity sewer systems
- Submarine pipelines and ocean outfalls
- Trenchless pipeline installation and rehabilitation
- Industrial process pipe work
- Compressed air services
- Electrical and telecommunication cable conduits
- Upstream coal seam gas and water pipelines
POLIplex® PE Pipes and Fittings System Technical Guide
POLlplex® polyethylene pipes offer the following benefits:
- Full axial restraint which eliminates the need for thrust blocks
- Low celerity material minimises water hammer
- UV stability for above ground pipelines
- Rust and corrosion free
- Long length availability to minimise joints
- Complete range of fittings
- Weldable using butt and electrofusion methods
- High ring stiffness for deeply buried pipelines
- Excellent abrasion resistance
- Possibility of 100+ year asset life
|Property||Value & Unit|
|Density (Specific Gravity)||955kg/m3|
|Hardness Shore D||63|
|Ring bending modulus (3 mins)||950MPa|
|Ring bending modulus (50 yrs)||260MPa|
|Property||Value & Unit|
|Coefficient of Thermal Expansion||1.8 x 10-4/°C|
Typical Fire Resistance Properties
|Property||Value & Unit|
|Spread of Flame||7|
Temperature effect on pressure rating
The co-efficient of thermal linear expansion of polyethylene varies with temperature but at ambient lies in the range 1.2 to 2.4 x 10-4 per degree C. In broad terms, this is about twenty times that of steel. and therefore unrestrained pipe will expand or contract much more than the steel structure that may be supporting it.
Should the pipe be fully restrained, the strain due to thermal change will generate stress in the material. However due to °the relatively low tensile deformation modulus of polyethy ene and assuming a typical ambient temperature fluctuation of less than 40 C, it can be assumed that the safe allowable stress will lnot be exceeded. Over the longer term, stress relaxation will increase the ability of polyethylene to accommodate high thermal strains.
The conductivity of polyethylene varies with temperature almost linearly and is typically O .4 7W/m.K at o•c to 0.37W/m.K al 70°C.
The specific heat of polyethylene varies with temperature from 1800 Joules/kg.Kat o•c to 2200J/kg.K at 60°C.
All temperatures above 25°C it is necessary to rerate polyethylene pressure pipe systems. The table below provides guidance as to the maximum operating pressure of PE100 pipes at temperature. It should be noted that at constant temperatures greater than 40°C, the 50-year design life of POLlplex ® pipes may be reduced.
Thermal rerating of PE100 polyethylene POLIplex® pipe
Maximum allowable operating pressure - PE100 Water pipe (m head)
|45 (35 y)*||31||49||62||77||99||123||154||192|
|50 (22 y)*||29||46||57||71||91||114||143||179|
|55 (15 y)*||29||46||57||71||91||114||143||179|
|60 (7 y)*||27||43||53||67||85||107||133||167|
|80 (1 y)*||20||32||40||50||63||80||100||125|
i. The values tabled are for POLlplex® pipe manufactured to AS/NZS 4130 and fittings made from compounds complying with AS/NZS 4131.
ii. The times given in years as (35y) are allowable extrapolation limits obtained by applying the factors in Table 1 of ISO 9080 to two years of test data at 80°C. Where appropriate. specific advice should be obtained from the manufacturer. and data provided shall be derived from testing to ISO 9080.
Visco – Elasticity
Tensile Strength and Modulus
Long-term Bursting Strength
Thermal expansion and contraction
The co-efficient of thermal linear expansion of polyethylene varies with temperature but at ambient lies in the range 1.2 to 2.4 x 10-4 per degree C. In broad terms, this is about twenty times that of steel, and therefore unrestrained pipe will expand or contract much more than the steel structure that may be supporting it.
Should the pipe be fully restrained, the strain due to thermal change will generate stress in the material. However due to the relatively low tensile deformation modulus (E) of PE and assuming a typical ambient temperature fluctuation of less than 40°C it can be assumed that the safe allowable stress will not be exceeded. Over the longer term, stress relaxation will increase the ability of PE to accommodate high thermal strains.
On the application of heat, polyethylene melts at between 120°C and 135°C and will catch fire at 340°C in the presence of name. Combustion is not self supporting if there is less than 17% oxygen present.
Under the appropnate conditions, polyethylene burns in air with a faintly luminous yellow flame to yield carbon dioxide and water. In uncontrolled fire conditions, other compounds can be produced including carton monoxide, aliphatic and aromatic hydrocarbons together with various oxygen containing substances.
This property refers to the passage of either liquids or gases through the molecular structure of a material. Polyethylene resin, being hydrophobic, has a low permeability to water vapour, It is also relatively impermeable to gases such as carbon dioxide. ethylene, natural gas, oxygen, methane, air and nitrogen.
It does, however, exhibit significant permeability to some other gases and liquids such as aliphatic, aromatic and chlorinated solvents which are soluble with polyethylene. As a general rule, the larger the vapour molecule or the more dissimilar in chemical structure to polyethylene, the lower will be the permeability. To calculate the loss of gas from a PE pipe Fick's first law is applicable. This can be written:
Volume of permeating gas (m3) = g ΠDLPT/t
g = permeability coefficient (m3 per m.MPa.day)
D = outside of diameter (m)
L = length of pipeline (m)
P = partial pressure (MPa)
T = time (days)
t = thickness (m)
When any elastic material, including polyethylene, is extended by a longitudinal force it will simultaneously contract in the lateral direction. The ratio of the (smaller) transverse strain to the longitudinal strain is the Poisson's Ratio for the material and ranges from 0.3 for metals to 0.5 for rubber polymers. For PE, a value of 0.4 is accepted for calculation purposes.
Because of the comparatively high circumferential strain in a PE pipe under normal operating pressures, the longitudinal contraction may be significant where there is no restraint. This can occur in above ground installations or where slip liners are not grouted. In these circumstances the pipeline may require anchoring to prevent separation, The ultimate circumferential strength of the pipes will increase slightly when axial contraction is prevented.
Problem: By what amount will a POLIplex One Hundred pipeline shorten due to Poisson's effect when operating at class PN head?
Circumferential (hoop) strain= Design Stress(MPa)/Long-term Modulus (MPa)
8.0/200 or 4%
Longitudinal = Poisson's Ratio x hoop strain
= 04 x 0.04
or 1.6% of length of pipeline
That is at maximum working head an unrestrained pipeline 100 metres long will shorten 1.6 metres and a 6 metre length joined with a mechanical coupling will contract 96 millimetres.
PE100 Material Composition
The PE100 polyethylene resin used in POLIplex® pipes and fittings are pre-compounded, either black or coloured with pigment, complying with AS/NZS 4131. Anti-oxidants are used to inhibit oxidation of the polymer at the compounding stage and during subsequent processing.
Carbon black is used in all black POLIplex® pipe at a concentration of 2.25 ± 0.25% by mass as an ultra violet radiation absorber.
In natural and coloured POLIplex® materials, hindered amine light stabiliser (HALS), ultra violet absorber. is used in lieu of carbon black.
Polyethylene is a polyolefin resin, in chemical terms a non-polar high molecular weight paraffin of the hydrocarbon family. Hence it is very resistant to (non-oxidising) strong acids, strong bases and salts. It is mildly affected by aliphatic solvents although aromatic and chlorinated solvents will cause some swelling. Polyethylene is affected by strongly oxidising substances such as halogens and concentrated inorganic acids. POLIplex® pressure pipes should not be used to convey water disinfected with chlorine dioxide at any temperature which has been found to rapidly deplete the antioxidant additives at elevated temperature.
Standards and Approvals
POLlplex® is an integrated family of polyethylene pipes produced by Iplex, based on PE100 resin. POLIplex® pipes are manufactured to AS/NZS 4130 from resin compounds complying with AS/NZS 4131 and are StandardsMark licensed to AS/NZS 4130 by third-party certifier SAI Global.
Colour and Markings
Iplex POLIplex® pipes are colour coded as per AS/NZS 4130 to easily distinguish between the different types of pipes applications. POLIplex® pipes can be manufactured all black, with stripes or coex.
POLIplex® PE100 pipe colour identification
|POLIplex® PE100 Black|
|POLIplex® PE100 Blueline||Drinking water|
|POLIplex® PE100 Purple Stripe||Recycled water|
|POLIplex® PE100 Cream Stripe||Sewerage|
|POLIplex® PE100 THERMAPIPE® White||Reduces absorption of heat|
|POLIplex® PE100 Yellow Stripe||Gas|
|Economy Rural Greenline||Rural|
Iplex Pipelines has published verified Environmental Product Declaration (EPD) on our range of Polyethylene pipes. EPD’s are third party certified documents based on ISO 14025 and EN 15804 Standards that communicate transparent and comparable information about the life-cycle environmental impact of a product or service. Specifically, product declarations include information on the environmental impact of raw material acquisition, energy use and efficiency, composition of materials and chemical substances, emissions to air, soil and water and waste generation.
POLIplex® Pipe Range and Dimensions
POLIplex® PE100 pipes are available from DN16 – DN2000
Rural Polyethylene Pipe Range and Dimensions
Iplex Greenline rural polyethylene pipe is rated to 800 kPa for use in rural applications. A range of rural compression fittings are available from ¾ inch to 2 inch.
Greenline economy rural pipe dimensions
|Nominal ID in (mm) (inches)||ID Ave (mm)||Wall Ave (mm)||OD Ave (mm)|
|25 (1 )||25.3||1.7||28.7|
|32 (1 ¼”)||31.6||2.0||35.6|
|40 (1 ½”)||38.0||2.4||42.8|
Manufactured with a highly reflective white material on the external skin, THERMAPIPE® reduces the absorption of heat.
POLIplex® Joining Systems
POLlplex® polyethylene pipes may be joined economically using thermal butt-welding or electrofusion equipment: alternately diameters up to DN 110 are commonly joined using lplex compression couplings complying with AS/NZS 4129. These fittings make joints quick and easy, which can be undone and reused when altering the system layout.
POLIplex® Friction Loss Charts
POLIplex® PE100 - Hydraulic Design – Pressure Pipeline Design for water and Sewerage
POLIplex® PE100 - Hydraulic Design – Selection of pipe diameter and class
POLIplex® PE100 - Hydraulic Design – Thrust Restraint and Anchorages
Handling & Storage
Handling & Storage
POLIplex® PE100 - Handling and Storage
Installation & Testing
Installation & Testing
POLIplex® PE100 - Installation
POLIplex® PE 100 - Testing
Above ground POLIplex® pipe support spans
Maximum spacing of supports for fixed installation
|Nominal outside diameter of pipe(mm)||Recommended maximum spacing of supports (metres)|
|Horizontal or graded pipes||Vertical Pipes|
Note: Design of support brackets for polyethylene pipes should include allowance for expansion and contraction. For more information please refer to AS/NZS 2033.
POLIplex® PE 100 - Safe Axial (Pulling) Load
Frequently Asked Questions
Are POLlplex® pipes resistant to ultra violet radiation?
Yes. POLlplex®pipes contain either carbon black or chemical stabilisers to protect them from the effects of ultra violet radiation. Black pipes are suitable for long-term external exposure to sunlight. Coloured pipe may be stored for up to 2-years in direct sunlight. For long-term exposure in above ground applications, lplex recommends the use of white THERMAPIPE®.
Do I need thrust blocks or other forms of restraint on POLlplex® pipelines?
Generally no. as POLIplex® pipes are fully welded or mechanically restrained, however it may be necessary to provide thrust restraint where POLlplex® pipelines connect to rubber ring jointed pipelines or other non restrained pipe or fillings. For more information, contact lplex Pipelines.
How do I pressure test POLlplex® pipelines?
Polyethylene pipes require a different test procedure to PVC or ductile iron pipelines to compensate for the materials tendency lo strain during pressure testing. If the correct test procedure is not used. the pipeline may appear to fail the test. Detailed information on the correct procedure is contained in Australian Standard AS/NZS 2033.
Can I use POLlplex® pipes to convey compressed air?
Yes. however they require rerating due to its elevated temperature and the stored energy contained in compressed air. Information is available in PIPA Industry Guideline POP002 "Polyethylene (PE) Pipes and Fillings for Compressed Air", which can be accessed at www.pipa.com.au.
What is the maximum temperature at which POLlplex® pipe can be used?
All temperature above 25°C, polyethylene pipes require pressure rerating. At very high temperatures as well as very low temperatures. the life of polyethylene pipes may be substantially reduced. For detailed information, refer to PIPA Industry Guideline POP013 "Temperature rerating of PE pipes", which can be accessed at www.pipa.com.au.
Are POLlplex® pipes affected by chemicals?
Whilst polyethylene is a highly chemical resistant material, there are some chemicals which are unsuitable for carriage in POLlplex® pipes, or may reduce their service life. For detailed information on most chemicals, refer to the Iplex Chemical Resistance Tool
Do I need any special training to con duct butt-fusion or electrofusion welding?
Yes. Welding by untrained operators is the most common cause of joint failure in polyethylene pipelines. Australian Standard AS/NZS 2033 stipulates that polyethylene welders must be trained and certified by a Registered Training Organisation and that welding procedures must be in accordance with PIPA Industry Guidelines POP00 1 "Electrofusion Jointing of PE pipe and fittings for pressure applications" and/or POP003 "Butt Fusion Jointing of PE pipes and fittings - recommended parameters". More information can be accessed at www.pipa.com.au.
How do I store electrofusion fittings?
Fittings should be stored out of the direct sunlight and in their original boxes and sealed plastic bags until immediately before use. Ideally, couplings should be stored on their flat ends.
Can I use an electrofusion fitting which has been removed from its original plastic bag?
Contamination is the most prevalent cause of failure of electrofusion fittings Failure to preserve the manufacturer's packaging of fittings increases the risk of UV oxidisation or surface contamination possibly rendering the fitting useless or unsaleable.
What can I use to clean electrofusion fittings prior to welding?
lplex Pipelines stock cleaning wipes that are ideal for installation preparation Methylated spirits contain residual oils that will contaminate the welding surface and should not be used.
How do I weld coiled pipe that has become oval?
Coiled pipe will become oval due to the stress induced during coiling and must be rerounded using the correct tools prior to welding. lplex stock a variety of rerounding equipment suitable for this purpose (Refer to page 100 for a list of available rerounding equipment).
What is the difference between SOR and PN ratings?
SOR is the Standard Dimensional Ratio of the pipe outside diameter to wall thickness. PN ratings are the nominal pressure rating of the pipe, but only at when it is carrying non-viscous fluids at 20°c. SOR is the preferred method for specifying the grade of pipe required.
What is the expected life of POLlplex® pipelines?
There are many factors that may affect the life of polyethylene pipelines They include temperature, fluid type, installation method, UV exposure and cyclic loading. Wien correctly installed in underground applications, POLlplex® pipes conveying water will have an anticipated service of in excess of 100 years.
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