Dear Imbayyah Alwirfili ...

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Dear Imbayyah Alwirfili

Recently we have completed a project name"Dhaka Water Supply Sector Development Project" where we upgraded our pipeline (water supply network) approximately 3000 KM. We used HDPE  material pipe and set the pipes by  trench less technology.  The specification are as below

1.1    Materials Requirements 
1.1.1   Pipe materials and jointing Pipe materials to be used for the project works shall conform to the standards described in this Requirements. If any material, not covered in these requirements, is required to be used, it shall conform to relevant International Standards or requirements specified by the Project Manager.  Three types of materials are expected to be used by the Contractors for DWSSDP namely High Density Polyethylene (HDPE) pipes, un-plasticized polyvinyl chloride (uPVC) pipes and Ductile Iron (DI) pipes depending on the field situation and requirements as described in this section. HDPE pipes will be used for trenchless technologies for pipe replacement and pipe extension, uPVC pipes may be used in case of conventional trenching methods. All pipes and fittings are intended to be used in Dhaka City Area for drinking water supply under pressure at normal temperature. The materials must be suitable for operation in the tropical climatic conditions that prevail in Bangladesh. Ambient temperatures are up to 50°C and humidity up to 95% at 35°C. The pipes and fittings shall be manufactured specially for surface installation in tropical humid climates with a prevailing water temperature of 35°C. Heavy rainfall and significant flooding usually occurs in Bangladesh during rainy season; dry and dusty conditions prevail for rest of the year. All pipes and fittings shall be new and unused.  The Contractor shall notify the Project Manager of his proposed sources of materials prior to delivery and submit test results of the said pipe type and dimension according to test method specified in this section.  After arrival to the site, all materials shall be subjected to an acceptance test prior to their immediate use. Test samples to be taken out before installation shall be taken out together with the Project Manger or his representative. The cost of sampling / testing shall be borne by the Contractor. If any sample does not conform to the prescribed tests and quality, the batch of pipes and / or fittings shall be rejected by the Project Manager or his representative and such materials shall be removed from the site by the Contractor at his own cost. Such rejected materials shall not be made acceptable by any modifications.  Jointing for pipes and fittings / specials shall be done in accordance with the relevant Specifications depending on type of pipes being used.  
1.1.2   High Density Polyethylene (HDPE) Pipes Standards ï‚·  The materials from which the pipes are made shall be in accordance with ISO 4427-1; ï‚· All High Density Polyethylene (HDPE) Pipes (PE 100) shall conform to the standard of ISO 4427-2: 2007(E) of PN 10 nominal pressure and SDR 17 Mean outside diameter shall be in accordance with ISO 11922-1: 1997 (grade B for sizes ≤630) and the maximum out of roundness (quality) shall be in accordance with ISO 11922-1: 1997 (grade N for sizes ≤630). Mean outside diameter and the maximum out of roundness for different diameter of the above mentioned series of PE 100 pipes (provided in the table given below); ï‚·   The pipe shall be coiled such that localized deformation, e.g. buckling and kinking, is prevented. Minimum internal diameter of the coil shall be not less than 18 x nominal diameter; ï‚·  The length of straight pipes and coils depends on the field requirement for the trenchless technology and minimum internal diameter of the coil. Contractor should supply the pipes accordingly; 
ï‚·   The wall thickness for different diameter of the above mentioned series of PE 100 pipes should be in accordance of the table given below; ï‚· Dimension of the pipes shall be measured in accordance with the ISO 3126; ï‚·  All testing at factory to be done in accordance with the provision in the relevant code/ specification. 
Nominal outside diameter  (mm) 
Mean outside diameter  (mm) 
Maximum out of roundness  (mm) 
Nominal wall thickness (mm) SDR 17 (S 8) PE 100 (PN 10) dem, min dem, max  emin emax 75 75 75.5 1.6 4.5 5.1 110 110 110.7 2.2 6.6 7.4 160 160 161 3.2 9.5 10.6 200 200 201.2 4.0 11.9 13.2 225 225 226.4 4.5 13.4 14.9 280 280 281.7 9.8 16.6 18.4 315 315 316.9 11.1 18.7 20.7 355 355 357.2 12.5 21.1 23.4 400 400 402.4 14.0 23.7 26.2 450 450 452.7 15.6 26.7 29.5  
Markings of pipes and fittings: 
All pipes shall be permanently and legibly marked in such a way that the marking does not initiate cracks or other types of failure and such that normal storage, weathering, handling, installation and use do not affect the legibility of the marking. If printing is used, the colour of the printed information shall differ from the basic colour of the product. The marking shall be such that it is legible without magnification. The frequency of marking being not less than once per meter. The size of marking shall be at least 10 mm height. The marking shall show the followings in order as stated below:  ï‚· The Manufacturer's name or Trademark and the text: "DWSSDP-2009, DWASA" (in bold letters) shall be marked on the surface of each pipe; ï‚·   The number of ISO Specification i.e. ISO 4427-2: 2007 (pipes), ISO 4427-3: 2007 (fittings); ï‚·  The designation of the pipe maternal e.g. PE 100; ï‚·  The fitting material and name of fitting e.g. HDPE Nipple; ï‚·  The nominal outside diameter, SDR series and Pressure (in bold letters) e.g. 200 mm, SDR 17, PN 10; ï‚· Production period (date or code) e.g. 0310. This looks like:  (Trademark name or symbol), DWSSDP-2009, DWASA HDPE, ISO 4427-2: 1996, 200 mm, SDR 17; 0310 
1.1.3   Jointing of HDPE Pipes and Fittings Butt Fusion Jointing Equipment Butt fusion jointing equipment shall be certified in accordance with ISO 12176-1. Only fully automatic Computerized Numerical Control (CNC) machines or computerized 
microprocessor based machines shall be used. Manual or Semi Automatic CNC machines are not allowed. Butt Fusion requirements Butt Fusion jointing shall be carried out in accordance with ISO 11413. Testing of such joints shall be in accordance with ISO 13953. Joints: When PE pipes are assembled to each other or components, joints shall be in accordance with ISO 4427: 2007. HDPE Pipes (PE 100) may be required to be joined by butt fusion (100 mm Ø or above) or using electro fusion fitting mixing different pipe material, the joint should conform to the requirement specified in the relevant code. Only pipes and fittings of the same material type, size and rating shall be butt welded, e.g. PE 100 pipes should not currently be welded to PE 80 pipes; PN 12.5 pipe should not be welded to PN 10 pipe or fitting.  
The most widely used method for joining individual lengths of PE pipe and PE fittings is by heat fusion of the pipe butt ends. Quality butt fusion joints may be produced by using trained operators and quality butt fusion machines in good condition. Anyway fusion and other standard practices like mechanical fittings (compression fittings, flanged joints etc.) as appropriate are to be followed depending on each joining situation the Contractor may encounter. Care should be taken to ensure that all pipe jointing is adopted in accordance with the manufacturer’s recommendations. Fittings: The Contractor may use following three types of fittings made from polyethylene (PE) for piping systems as per ISO 4427-3: 2007. ï‚·   Spigot Fittings: Spigot fittings are injection moulded fittings and / or fitting which are assembled using butt fusion joints. The dimensions of spigot fittings up to and including nominal size 63 shall conform to the requirements of ISO Standards; ï‚·   Electro-fusion Fittings: Electro-fusion fittings shall be injection moulded fittings made of PE but incorporating integral heating element(s) to enable fusion with PE pipes. Installation shall be carried out in accordance with ISO 11414; ï‚·  Mechanical Joints and Fittings: The materials and constituent elements used in making the fitting (including elastomers, greases and any metal parts) shall be as resistant to the external and internal environments as the other elements of the piping system and shall have a life expectancy under the following conditions as least equal to that of the PE pipe conforming to ISO Standard.  
The requirements for the level of material performance for non-polyethylene parts shall be at least as stringent as that of the PE pipe systems. All mechanical joints and fittings shall be of approved types designed specifically for PE pipe system and shall conform to the requirements specified in the following table. The fittings shall be supplied with all necessary coupling rings, nuts, bolts, washers, rubber rings / sealing gaskets and  restrainers / stiffeners.  

You can visit Bangladesh to see this success project.

Best regards

Dr.J.T.A.Chowdhury