CM4120 Unit Operations Lab Piping SystemsSlide 2Slide 3Slide 4Slide 5Slide 6Slide 7Slide 8Slide 9Slide 10Slide 11Slide 12Slide 13Slide 14Slide 15Slide 16Slide 17Slide 18Slide 19Slide 20Slide 21Slide 22Slide 23Slide 24Slide 25Slide 26Slide 27Slide 28Slide 29Slide 30Slide 31Slide 32Slide 33Slide 34Slide 35Slide 36Slide 37Slide 38Slide 39Slide 40Slide 41Slide 42Slide 43Slide 44Slide 45Slide 46Slide 47Slide 48Slide 49Slide 50Slide 51Slide 52Slide 53Slide 54Slide 55Slide 56Slide 57Slide 58Slide 59Slide 60Slide 61Slide 62Slide 63Slide 64Slide 651CM4120Unit Operations LabPiping SystemsPiping Systems in the Chemical Process IndustriesMarch, 2009IntroductionBasis for DesignPiping Codes and StandardsDesign of Process Piping SystemsJoints and FittingsValves2CM4120Unit Operations LabPiping SystemsPiping Systems include:Pipe, Flanges, FittingsBolting, GasketsValvesHangers and SupportsInsulations, Coverings, CoatingsHeat Tracing3CM4120Unit Operations LabPiping Systems“Piping systems are like arteries and veins. They carry the lifeblood of modern civilization.”Mohinder Nayyar, P.E.Piping Handbook, 7th ed.McGraw-Hill, 20004CM4120Unit Operations LabPiping SystemsPrimary Design Consideration is Saf e tyEvaluate Process ConditionsTemperaturePressureChemical compatibility/Corrosion allowancesVibration, flexing, bendingExpansion/Contraction due to temperature changeEnvironmental conditionsEvaluate the Effects of a LeakEvaluate Performance in a Fire Situation5CM4120Unit Operations LabPiping SystemsSecondary ConsiderationsEvaluate any Special RequirementsSanitary requirements – “Cleanability”Serviceability – ease of maintenance of equipmentPossible contamination of process fluid by piping materials, sealants, or gasketingEarthquake, Hurricane, Lightening, PermafrostLowest Cost over the Lifetime6CM4120Unit Operations LabPiping SystemsPiping System Routing and LayoutThe unwritten #1 rule:Serviceability/Operability7CM4120Unit Operations LabPiping SystemsPiping System Design Criteria4 areas to consider:Physical AttributesLoading and Service ConditionsEnvironmental FactorsMaterials-Related Considerations8CM4120Unit Operations LabPiping SystemsCodes and Standards simplify design, manufacturing, installation processStandards – provide design criteria for componentsstandard sizes for pipedimensions for fittings or valvesCodes – specific design/fabrication methodologiesIncorporated into local/regional statute It’s the LAW9CM4120Unit Operations LabPiping SystemsASME Boiler and Pressure Vessel CodeASME B31: Code for Pressure PipingANSI Standards – dimensions for valves, piping, fittings, nuts/washers, etc.ASTM Standards for piping and tubeAPI – Specs for pipe and pipelinesAWS, ASHRAE, NFPA, PPI, UL, etc.10CM4120Unit Operations LabPiping SystemsASME B31 Pertinent sectionsB31.1 – Power plant boilersB31.3 – Chemical plant and refinery pipingB31.4 – Liquid petroleum transportB31.7 – Nuclear power plant radioactive fluids11CM4120Unit Operations LabPiping SystemsASME B31.3 – Chemical Plant and Refinery Piping CodeIncludes piping systems in:Chemical and refinery plantsPharmaceutical and food processingTextile and paper plantsBoilers12CM4120Unit Operations LabPiping SystemsASME B31.3 covers:Materials of constructionPiping design processFabrication, Erection, AssemblyDesign of supportsExamination, inspection, and testing13CM4120Unit Operations LabPiping SystemsPiping Design Process – a three step approach1.Design for FlowFind min. diameter to achieve desired flow velocity2.Design for Pressure IntegrityFind min. wall thickness for process and external conditionsFind appropriate rating of in-line components3.Re-check for Flow Criteria14CM4120Unit Operations LabPiping SystemsStandard Pipe SizesDiameters are “Nominal”Sizes 12” and less, nominal size < ODSizes 14” and over, nominal size = ODWall thickness inferred thru “Schedule”Defined Schedules:5, 10, 20, 30, 40, 60, 80, 100, 120, 140, 16015CM4120Unit Operations LabPiping SystemsStandard Tubing SizesSteel tubingDiameters are Actual ODWall thickness is specifiedRefrigeration TubingSingle wall thickness available for each sizeActual ODCopper Tubing – Nominal sizesType K, L, M16CM4120Unit Operations LabPiping SystemsCriteria for Design for FlowEconomicsServiceable over Design LifeSmallest diameter usually is lowest costPerformanceMinimum entrainment velocityPrevent erosion or cavitation17CM4120Unit Operations LabPiping SystemsDesign Rules of Thumb when sizing for velocity...Water lines: 3-10 ft/secPump discharge: 3-12 ft/secPump suction: (1/3 x discharge velocity)Steam: low pressure (25 psig or less) 50-100 ft/sec high pressure (>100 psig) 100-200 ft/secSlurries: > min. entrainment velocityfrom Peters and Timmerhaus, Plant Design and Economics for Chemical Engineers, 4th ed., McGraw-Hill, 1991.18CM4120Unit Operations LabPiping SystemsSelecting appropriate pipe ScheduleSchedule = P/S * 1000P = max. working pressure of pipe, psigS = allowable stress in piping material, psiFor carbon steel pipe, S = 36,000 psiWhat is max. working pressure for Schedule 40 Carbon Steel pipe?psigP 14401000000,36*4019CM4120Unit Operations LabPiping SystemsDetermine min. req’d wall thickness:Pressure Integrity Design MethodASME B31.3, APySEPDtm2tm=min. wall thicknessP=design pressure, psigD=O.D. of pipe, in.S=allowable stress, psiE=weld joint efficiencyy=factor to adjust for tempA= add’l thickness for corrosion, external loads, etc.20CM4120Unit Operations LabPiping SystemsAfter determining wall thickness:Re-check ID for velocity;Select in-line components;Determine insulation, coverings, coatings;Design and locate supports and hangers.21CM4120Unit Operations LabPiping SystemsInline Components:FittingsValvesGaskets, Seals, and Thread SealantsConnection Hardware – Bolts, studs, nuts, washers22CM4120Unit Operations LabPiping SystemsPipe Fittings - SteelForgedCastMalleable IronSelect “Class” of Fittings150 lb., 300 lb., 600 lb., etc.Need a look-up table to determine max. allowable P at the design temperature23CM4120Unit Operations LabPiping SystemsMaximum Allowable non-shock Pressure (psig)Temperature(oF)Pressure Class Rating for Flanged Fittings (lb)150 300 400 600 900 1500 2500Hydrostatic Test Pressure (psig)450 1125 1500 2225 3350 5575 9275-20 to 100 285 740 990 1480