PE SYSTEM CHEMISTRY THAT MATTERS - Saudi Hepco LLC

Pipe ExtrusionSAUDI HEPCOPipe ExtrusionSaudi Hepco PE pipes are extruded using sophisticated, highly controlled manufacturing processes and technologies. The PE raw materials used in extrusion are compounded into pelletized form containing precise amounts of polymer, lubricants, stabilizers,antioxidants and pigments for the specific end product application.  The PE compoundis preheated to remove moisture and volatiles and is conveyed into the extruder by acontrolled rate feeder.PE ExtruderThe extruder consists of a single screw configuration, which melts and conveys thePE material along the length of the extruder barrel. The design of the extruder barrel/screw is complex and takes into account the properties of the various types of PEmaterial grades used in pipe applications. Various zones exist along the length of thescrew and act to melt, mix, de-gas and compress the PE compound. External electricalheater bands along the barrel, together with the frictional heat generated as the PEmaterial passes through the gaps between barrel and screw provides the energy needed to fully melt the PE compound materials. The total heat input is carefully controlledto ensure full melting of the PE without thermal degradation.The pipe information of size, material, class, and batch datarequired by SASO Standards, or by specific client specification, is then marked on the pipe by an in-line printerto provide continuous branding at specified intervals. Thecompleted pipe is then cut to standard or required lengthby an in-line saw, and then packed into stillage, or for largediameter pipes stored. Small diameter pipes are eithercut to standard length, or coiled, and the finished coils arestrapped in standard coil sizes.After passing through a mixing zone at the tip of the extruder, the PE melt then feedsinto a head and die combination, where the melt is formed into the size of piperequired. The correct design of the head and die is essential to permit the productionof pipe to SASO Standards requirements and to ensure retention of the physical properties of the PE materials. Once the molten PE pipe form leaves the die, it enters thesizing system, where it is initially cooled to the required dimensions. This is performedusing an external vacuum pressure system where the pipe surfaces are cooled withrefrigerated water sprays whilst in contact with precision machined sizing sleeves.The initially cooled pipe is then progressively passed through a series of water spraycooling tanks to reduce the PE material to ambient temperature, and to finalize thepipe dimensions. As the pipe passes along the extrusion line, it is pulled along at aconstant speed using a caterpillar track haul off. This haul off speed is closely co-ordinated with the speed of the extruder output using closed loop process controllers, tominimize built in stress in the pipe.1011

Chemical ResistanceChemical ResistanceIt is generally known that pipes and fittings in thermoplastic material are widely used inindustries where conveyance of highly corrosive liquids and gases require high-qualityconstruction materials, featuring excellent corrosion resistance. Stainless steel coatedsteel, glass and ceramic materials can often be advantageously replaced by thermoplastic materials, ensuring safety, reliability and economic benefits under similar operatingconditions.SAUDI HEPCOFactors Affecting Chemical ResistanceA number of factors can affect the rate and type of chemical attack that may occur.These are:Concentration: In general, the rate of attack increases with concentration, but in manycases there are threshold levels below which no significant chemical effect will be noted.Temperature: As with all processes, rate of attack increases as temperature rises.Again, threshold temperatures may exist.Chemical Attack on Thermoplastics & ElastomersChemicals that attack polymers do so at differing rates and in differing ways. There aretwo general types of chemical attacks on polymer:1. Swelling of the polymer occurs but the polymer returns to its original condition if thechemical is removed. However, if the polymer has a compounding ingredient that issoluble in the chemical, the properties of the polymer may be changed because of theremoval of this ingredient and the chemical itself will be contaminated.2. The base resin or polymer molecules are changed by crosslinking, oxidation, substitution reactions or chain scission. In these situations the polymer cannot be restored bythe removal of the chemical. Examples of this type of attack on PVC are aqua regia at20 C and wet chlorine gas. Reference NSF case study in Egypt.Saudi Hepco PE advantageThe outstanding resistance of Saudi Hepco polyethylene systems to a variety of chemical reagents, allowtheir use in a wide range of chemical processes. Chemical resistance of polyethylene is due to the non-polaror paraffinic nature of the material and is a function ofreagent concentration and temperature. Some attackmay occur under specific conditions however, use ofSaudi Hepco polyethylene systems provides a costeffective solution when the behavior of polyethylene iscompared to that of alternative materials.1213

General Effect of Chemicals on Polyethylene PipeGeneral Effect of Chemicals on Polyethylene PipeResistant: Water, solutions of inorganic salts, weak acids, strong organicacids, strong alkaline solutions, aliphatic hydrocarbons.Has adequate resistance: Strong acids, hydrofluoric acids, fats and oils.Has limited resistance: Lower alcohols, esters, ketones, ethers, aromatichydrocarbons, and mineral oil.In most cases non-resistant: Light naphtha, fuel mixture.Completely non-resistant: Unsaturated chlorinated hydrocarbons turpentine.SAUDI HEPCOClassed by Materials Polyethylene pipes are also classified by the typeof material used: PE 32 - low pressure piping systems PE 40 - low pressure piping systems PE 63 - medium pressure piping systems - irrigation system - drinking water connections PE 80 - gas pipe for natural gas distribution network with pressure rate up to 4 bars - drinkingwater pipe with pressure rate up to 16 bar - sewers, outfall pipes, industrial pipes PE 100 - high demands piping applicationsPE pipes can be used in range of temperatures from -40 C to 0 C consideringthe change of operating pressure. Typically the standard specification identifiesclass of a HDPE pipe is by the nominal pressure class - PN - up to PN 20 or 20bar. HDPE pipe can also be classified by the material used - PE 100, PE 80, PE63, PE 40 or PE 32. Pressure Nominal – PN PE pipes are produced in differentpressure grades (PN grades), which indicates the pressure in bars the pipe cansupport with water at 20 C.Color Codes and Pressure GradesColor codes used to indicate the pressure grades on the pipes are:Color CodePE Pressure GradeYellowPN 4RedPN 6BluePN 10GreenPN 16The pressure grades available according toEuropean standards are: PN 2.5 - max pressure 2.5 bar PN 4 - max pressure 4 bar PN 6 - max pressure 6 bar PN 10 - max pressure 10 bar PN 16 - max pressure 16 bar 1 bar 105 Pa (N/m2) 0.1 N/mm2 10,197 kp/m2 10.20 m H2O 0.9869 atm 14.50 psi (lbf/in2) 106 dyn/cm2 750 mmHgThe Minimum Required Strength - MRS - according ISO 4427for the different materials are:Designation of materialPE 100PE 80PE 63PE 40PE 32MRS at 50 years & 20 C MPa (bar)10 (100)8 (80)6.3 (63)4 (40)3.2 (32)Color Codes and Materials Classifications Common colors used to classify the pipes Completely black for industrial applications Completely blue, or black with blue stripes, for potable water Completely yellow, or black with yellow stripes, for gas conduitsNote: That the colors may depend on country1415

HDPE Pipe & Field ApplicationsSAUDI HEPCOHDPE Pipe & Field ApplicationsHigh-density polyethylene pipe (HDPE) can carry potable water, wastewater, slurries, chemicals, hazardeous wastes, andcompressed gases. In fact, polyethylene pipe has a long anddistinguished history of service to the gas, oil, mining and otherindustries. It has the lowest repair frequency per mile of pipe peryear compared with all other pressure pipe materials used forurban gas distribution.Polyethylene is strong, extremely tough and very durable.Whether you’re looking for long service, trouble-free installation,fle xibility, resistance to chemicals or a myriad of other features,high-density polyethylene pipe will meet all your requirements.AGRICULTURE & IRRIGATION Flood Irrigation (Suction & Delivery pipes in pump sets) Sprinkler Irrigation (Crops, Lawns, Golf course, Gardens) Drip irrigation (Plantations, Orchards, Nurseries)WATER SUPPLY Potable water supply Water mains Distribution Service PipesSEWAGE & INDUSTRIAL EFFLUENT DISPOSAL Domestic Sewage System Sanitary System Petrochemical Industry Fertilizer IndustryELECTRICAL AND TELECOM INSTALLATIONS Conduits for Cables Hydraulic Directional Drilling (HDD)for power and telecom cablesDRAINAGE PIPES Surface & Rain water Waste Water Mains Sub-soil waterAdvantages Low specific weight Excellent Weldability Smooth inside surface Less frictional resistance so less pressure drop Suitable and approved for food and potable water Laying ease joining and reliabilityResistance toUltraviolet rays, Weathering, Chemicals, Heat Aging,Abrasion, Rodents, Freezing, Microbes Freezing1617

PE 100PE 100PE 100 is a black high-density polyethylene designed for water pressure pipes, irrigationchemical, and industrial and underground drainage systems. PE 100 contains minimum2% of well dispersed, fine particle sized carbon black and stabilizers to ensure excellentweathering resistance and long term stability. PE 100 shows excellent resistance to rapidcrack propagation and slow crack growth, both being important parameters for pressurepipe design. PE 100 can be joined by easily welded butt-fusion, using standard HDPEparameters or by electro fusion. PE 100 raw material has the highest performance of allHDPE material (PE 80)SAUDI HEPCOThe following table list physical properties of Polyethylene thermoplastic materials. Variations may existdepending on specific compounds and products:PHYSICAL PROPERTIESTYPICAL VALUESUNITDensity 959 Kg/m3TEST METHODISO 1183MFI 190 C/5kg 0.25 g/10 min ISO 1133Tensile Stress at Yield 50 mm/min25MpaISO 527-2Elongation at break 100 % ISO 527-2Saudi Hepco manufactures polyethylene systems in both PE80 and PE100. The numbersrelate to the minimum required strength values of the material.Charpy impact notched (0) C16Kj/m2IS0 179/IeAHardness, Shore D 60 - ISO 868Carbon Black Content 2%ASTM D 1603Brittleness Temperature -70 C ASTM D 746ESCR 10000 h ASTM D 1693 -AThermal Stability 210 C 15 min EN 728PE80This is the term used to denote thepolyethylene material, which has beenwidely used for gas, water and industrialapplications.PE100This is a term used to denote highperformance polyethylene, it demonstrates exceptional resistance to rapidcrack propagation as well as to long termstress cracking.1819

StandardsHDPE Pipes Standard SizesSAUDI HEPCOGeneral Standards - Applicable to Hepco ProductsStandardTitleProductsHDPE PRESSURE PIPE PE 100 MRS 10 SIGMAISO161-1:1996Thermoplastic pipes-nominal outside diameter andnominal pressuresAll pipes and fittingsISO 4065:1996Thermoplastic pipes-universal wall thickness tablesAll pipesBS ISO11922-1:1997Thermoplastic pipes for the conveyance of fluids dimensions andtolerances metric seriesAll pipesDimensioning according to DIN 8074 - ISO 4427 / 1167Material Color DimensionsHigh Density Polethylene PE 100BlackDIN 8074 / 8075MRS 10 MpaO’S 8 Mpa (MRS/c), (c 1,25)BS EN1092-1:2007Flanges and their joints – circular flanges for pipes, valves,fittings and accessories, PN designatedAll flange backing ring drillings,PN16 and PN 10Water StandardsStandardTitleProductsBS 6920Suitability of non-metallic products for use in contact with waterAll pipe material,Part 1:2000for Human consumption with regard to their effect on waterall fitting Materials, all PE100Part 1 Specification fittings and matching pipesBS 6920Part 2:2008Suitability of non-metallic products for use in contact with waterfor Human consumption with regard to their effect on waterPart 2 Methods of testAbbreviationsPNNominal Presure (Bar)WtPipe Weight (kg/m)SWall Thickness (mm)DaNominal Outside Diameter (mm)SDRStandard dimensional ratio (Da/s)MRSMinimum required strenght (Mpa)O’SHydrostatic design stress @20cCDesign factor 1,25 for waterAll pipe materials, all fittingMaterials, all PE100 fittingsand matching pipesPIPE SERIESS8Standard Dimensional RatioISOPE pipes for water supplyBlue and black PE80 and4427:2007 PE100 pipes and fittingsSDR 17SDR 11Nominal Pressure PN for O’S 8 MpaBS ENSpecifications for polyethylene components and systemsBlue and black PE80 and15494:2003 PE100 pipes and fittingsBS ENPlastic piping systems for water supply – polyethyleneBlue and black PE80 and12201:2003 PE100 pipes and fittingsBS EN805:2000Water supply requirements for systems andcomponents outside buildingsExternal water supply installationsBS EN681-2:2000Elastomeric seals, Materials requirements for pipe joint sealsSeals and flange gasketsused in water and drainage applications. Thermoplastic elastomers.BS 5306:1990Fire extinguisher installations and equipment on premisesBlue and black PE80 and PE100 forPart 2 external buried fire mainsBS 6572:1985Specification for blue polyethylene pipes up to nominal size63 mm for below ground use for potable waterS5SDR 10Nominal OutsideDiameter (Da)mm7590110125140160NominalPipe mmAverageWeightkg/mNominalPipe 4,0805,0806,670The weight may vary according to polymer density.The mass has been calculated taking average densty df 0,95 g/cm3Blue PE80 pipes and up to andincluding 63 mmDIN 8074:1999Pipes of high density polyethylene (HDPE) type 2 – dimensionsBlack PE80 and PE100 pipes insizes up to 1600 mmDIN 8075:1999Pipes of high density polyethylene (HDPE) type 2 – testingBlack PE80 and PE100 pipes insizes up to 1600 mmDIN 16963:198020Part 1 – High density polyethylene (HDPE)fittings dimension, type 2Black PE80 and PE100 spigot &electrofusion fittings up to 1200 mm21

SAUDI HEPCOComparison of SDR and Pressure Ratings for PE 80 and PE 100 MaterialsSDR 41 SDR 33 SDR 26 SDR 21 SDR 17 SDR 13.6 SDR 11 SDR 9 SDR 7.4PE 80 PN 3.2 PN 4PN 6.3 PN 8PN 10PN 12.5 PN 16 PN 20PE 100 PN 4PN 6.3 PN 8PN 10 PN 12.5 PN 16 PN 20 PN 25Standard Dimensional Ratio (SDR) – Ratio of nominal (minimum) outside diameter and minimum wallthickness remains constant for a given pressure rating of the pipe, this relationship is called SDR.Pipe End Reversion and Ovality – A slight taper effect occurs at the ends of a pipe length or at cut ends,therefore outside diameter should be measured at a distance of at least one diameter from the end of thepipe. This effect is not detrimental if site jointing is done properly. Extruded PE pipe will exhibit about 3.5%with straight pipes, up to 6% for coiled SDR11 pipes and 12% for SDR17/SDR17.6.Pipe Bending Radius for PE – The minimum bend radius for Hepco PE pipes is 15 times the pipe OD underoptimum conditions (i.e. warm ambient temperature and thick wall / low SDR pipe).Expansion and Contraction – The average coefficients of linear thermal expansion between 20 - 60 C are(1.5 x 10-4 C-1) for PE80 (MDPE) and for (1.3 x 10-4 C-1) PE100 are about ten times greater than for metal.SPressurization – The relationship between circumferential hoop stress and internal pressure is as follows:DaPN 2 x O’S x S x 10 / Da - SPipe Series O’S x 10 / PNPE 100 high impact strength compared to other materials ensures a greater resistance to the rigors of pipelaying conditions.PE 100 has low notch sensitivity providing high level of resistance to the effect of external damage especiallyimportant for pipe bursting operations and likelihood of such damage is present.PE 100 pipes are easy to install, have high flow capacity and long life proven reliability.PE80 and PE100 are not recommended for continuous pressure operation at temperatures above 60 C forliquids, including sewerage and industrial effluents, or 40 C for gaseous fluids. PE100 has advantages overPE80 at low temperatures, since it is extremely crack resistant down to -20 C.22Hoop Stress (MPa) Internal Pressure (bars) X (Pipe SDR -1)/20The associated longitudinal stress generated in a restrained PE pipeline is the product of circumferential hoopstress and Poisson’s ratio (0.48 for PE). This stress acts over the pipe cross sectional area to produce a tensileend load, which is independent of pipe length.Insulation – PE is a good insulator.Abrasion Resistance - PE has significant advantages over other pipe materials where internal resistanceto abrasion is required and is thus used in applications where abrasive materials such as china clay slurry, flyash and various industrial effluents are transported.Chemical Resistance – PE has good resistance to chemical attack. PE does not rot, rust, pit, corrode or losewall thickness due to chemical or electrical reaction with surrounding soil. Algae, fungi or bacteria do notaffect PE.23

Health and SafetyJointing MethodsHealth and SafetyJointing MethodsHepco products have been widely installed and used safely over many years. However, good practice is vital to ensuresafety, our products should be handled and processed in accordance with the British Plastics Federation guidelines. AllPE80 and PE100 pipe systems contain trace quantities of process residues and may also contain other materials such aspigments, antioxidants and UV stabilizers. Chemically unreactive, PE is regarded as being biologically inert, though somepipe materials contain low levels of additives, which may be toxic.Heat fusion (sometimes called heat welding, Butt welding or simply Fusion) is a welding process used to join two different pieces of a thermoplastic. ASTM Standard D2657, 2007, “Standard Practice for Heat Fusion Joining of PolyolefinPipe and Fittings”.InhalationPE does not release harmful fumes at ambient temperature. The threshold limit value of PE is 10mg/m3 (8 hour timeweighted average in the working environment), but generation of such levels when working with PE pipe or fittings isextremely unlikely.This process is commonly used in plastic pressure pipe systems to join a pipe and fitting together, or to join a length ofpipe directly to another length of pipe. Generally, polyolefins (such as polypropylene, polyethylene, and polybutylene)are used for these applications.IngestionIngestion of PE should be avoided. Some pipe materials may contain additives, which are harmful if swallowed. Materialsspecified for purposes other than carrying water may contain pigments, which are not suitable for use with potable water.These materials may be hazardous if ingested in large quantities.SAUDI HEPCOButt welding is usually performed using one of several methods. The first, and most common, is butt welding or buttfusion, which is a type of hot plate welding. This technique involves heating two planed surfaces of thermoplastic material (typically polyethylene) against a heated surface. After a specified amount of time, the heating plate is removedand the two pieces are pressed together and allowed to cool under pressure, forming the desired bond. Butt weldingoutside of manufacturing is usually performed to join pipes.Physical ContactPE is not considered to be a skin irritant. Cutting o

HDPE Pipe Field Applications [PE 100] Saudi Hepco PE Pipes Standard Sizes and Diameters Health and Safety Jointing Methods Quality Control and Assurance Transportation, Storage and Handling of PE Pipes Installation Guide Management commitment This Technical &