Composites – What Is Piping: All about Piping Engineering

What are composites? Composites are the novel materials made by combining two or more materials, the resultants of which possess the combination of better properties of the ingredients. Constituents of composites Base material – Matrix – metal, ceramic or polymerReinforcement – e.g. fiberFillers Dual Laminate Composite Thermoplastics lined to thermosets e.g. PVC-FRP, CPVC-FRP, PVDF-FRP, ECTFE-FRP, PP-FRP, FRP-FRPFRP - made of fiberglass impregnated with either – Unsaturated polyester resinVinyl ester resinFuran resin Fiberglass – provides structural stability Fig. 1: Service conditions for dual laminate composites Various other combinations of Composites FRP-Polymer ConcreteFRP-SteelFRP-ConcreteThermoplastic reinforced cement concreteThermoplastics on Steel FRP-Polymer Concrete Unsaturated polyester resin filled with quartzCast like concrete in moldsHigh compressive strengthHigh corrosion resistantHigh impact strength Application: used for electrolytic cells in copper refineries replacing lead-lined RCC cells Fibre Reinforced Composites Glass is the chief reinforcement used for composite materials in chemical process industries. Mostly in the form of GRPs S-glass – for high strengthC-glass – corrosion resistantCarbon fibers – superior mechanical properties, low density and corrosion resistant used for offshore oil field applicationsFor same strength: CFRP composite 80% lighter than steel60% lighter than aluminum Applications of GRP composites Resistant to most of the chemicals including acids, where metals like SS and Ni-alloys fail to survive Also handle lethal and corrosive Chlorine gas, halide salts, bleaching solutions including hypochlorite Unlike metals, can withstand wide fluctuations in pH and temperature. E.g. effluent treatment process Resistant to corrosion in damp soil conditions, oxidizing and reducing agents such as H2S Industries served Water and waste-water treatmentPulp & paperFood/chemical processingMining-mineral recoveryMicroprocessor manufacturingPharmaceuticalPower generation Chemical Industry Applications Storage tanks and Pressure vesselsPipingChimney and StacksFGD applicationsOffshore applicationsStorage tanks and Pressure vesselsComposites are attractive for this application due to the following parameters:Corrosion resistance, strength & ease of fabricationInstalled cost as compared to SS or CS-lined e.g. CNG tanks Dimensions: Diameter: 1 to 10mWall thickness: 5 to 50mm Fig. 2: Typical Anti-Corrosive Composite Pipes Composite Piping GRP piping applications includePotable water distributionFirewater systemsCooling water linesHandling De-mineralized waterEffluent systemsHigh-pressure pipelines handling aggressive media such as saltwater, oil, or brineUnsaturated polyester, vinyl ester resin used for Chimney and Stacks.Can withstand high temperature (up to 240 Degree C) and severe corrosive gasesCarbon fiber reinforcements, epoxy resins are used only in selective cases, wherein high strength and lightweight is more important besides corrosion resistance.Deep well platforms – tension leg platforms(TLPs) spars and drilling riserschoke and kill lines Offshore Applications Secondary structures including ladders, handrails, and gratingsFlow and gathering linesFirewater linesCasingsSurface injectionSaltwater disposal linesCO2 handlingTank battery piping Materials used in Offshore composites Bisphenol(A) polyester, bisphenol vinyl ester, Novalac epoxy, and phenolics – Fire retardant Summary Glass fiber reinforced composites are being selectively used in chemical process and oil & gas industries for the following advantages: Exceptional freedom of design and manufacture of many complex shapes.Outstanding durability even in extremely harsh environmentsA custom selection of resin and reinforcementsSuperior strength and stiffness to weight ratiosHighly corrosion resistant in almost every chemical environmentLower maintenance and replacement costs Glass Lining Glass Inert, hard and biologically inactiveCan be formed into a very smooth and impervious surfaceBrittle in nature Types of Pfaudler Glass World Wide Glasteel 9100Pharma Glass PPGStainless Steel Glass 4000Ultra Glass-6500Anti-static Glass World Wide Glasteel 9100 Offers an unmatched combination ofCorrosion resistanceImpact StrengthThermal shock resistanceNon-adherenceHeat transfer efficiency Stainless Steel Glass 4000 Reliable glass lining of stainless steel for pharmaceutical / FDA applicationsSuitable for cryogenic processes & pure products for electronicsA virtually inert glass that resists corrosion, abrasion and product adherence Pfaudler Ultra Glass Addresses the requirement of chemical reactions at high temperaturesEnhanced thermal tolerance up to 343 Degree C – an improvement over WWG 9100Extended thermal shock protection for faster heating and cooling Limitations: Operating temperatureChemicalsCavitationElectrostatic dischargeAbrasion FRP What is FRP? FRP is a resin lining into which layers of Fibers are incorporated to optimize lining structure capability and performance. Types of FRP Glass Fiber Reinforced Plastics (GFRP)Carbon Fiber Reinforced Plastics (CFRP)Polymer (Aramid) Fiber Reinforced Plastics (PFRP) Why FRP? FRP is widely used because of its relatively low cost, good chemical resistance, and its mechanical properties:Specific tensile strength (GPacm3/gm) – Tensile strength per unit densitySpecific stiffness (GPacm3/gm) – Tensile modulus per unit density Scope of Use of FRP The bottom lining of ASTPipingAutomotiveNavalAerospace Why tank lining? An effective method for preventing internal corrosion in storage tanksMaintaining the stored chemicals purity and qualityThe long lifetime for storage tanksTo overcome tank bottom perforations due to external corrosion Graphite Impervious Graphite is a traditional material selected for high conductivity, chemical resistance, and good mechanical properties. It is specially treated with synthetic resins to ensure that the base structure is fully impervious to liquids under pressure. Graphite forms no compounds due to corrosion, no surface films as do many metals. Hence graphite surface remains smooth and more resistant to scale build-up. Graphite lining can replace most of the other types of linings due to: Better thermal conductivitySuperior chemical corrosion resistance. Corrosion loss is < 0.05mm/yrLower initial/lifetime costsHas higher temperature applications compared to all the polymeric linings except for PTFE familyThe trouble-free operating life of approx. 5 yrsCan be used for lining very large size equipment Regularly available equipment with graphite Reaction vesselsHeat exchangersFalling film absorbersAcid dilution unitsTail gas scrubbersRaschig ringsDry HCL gas handling equipmentImpervious graphite tiles Patch repairs: Can be repaired easily as compared to other linings, especially glass lining. Few more useful Resources for you… An Article on Forms of Corrosion Corrosion under insulation: A Presentation Corrosion Protection for Offshore Pipelines Corrosion Monitoring Techniques & Surveys: A short Presentation Guide for Coating Selection for External Bolting to Reduce Corrosion Application of Anti-Corrosive Linings in Oil and Gas Industry