AvoidingPressureSurgeDamageinPipelineSystems：避免在管道系統(tǒng)壓力沖擊損傷32張精選課件

1、Avoiding Pressure Surge Damage in Pipeline SystemsPresented byGeoffrey D Stone CP Eng FIE Aust第1頁，共32頁。Firstly Quantify the Problem“In physical science the first essential step in the direction of learning any subject is to find principles of numerical reckoning and practicable methods for measuring

2、 some quality connected with it. I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind; it may be the begi

3、nning of knowledge, but you have scarcely in your thoughts advanced to the state of Science, whatever the matter may be.Lord Kelvin PLA, 1883-05-03第2頁，共32頁。Australian & International Codes & StandardsPressure Vessel Code AS 1210Arc Welded Steel Pipe AS 1579Submarine Pipeline Code AS 1958Installation

4、 of UPVC AS 2032Installation of PEAS 2033Buried Flexible Pipelines Design AS 2566Gas & Liquid Pipeline CodeAS 2885GRP Pipes for Water & Sewerage AS 3571Installation of ABS Pipes AS 3690Pressure Piping Code AS 4041WSA 01 Polyethylene Pipeline CodeWSA 02 Sewerage Code of AustraliaWSA 03 Water Supply C

5、odeWSA 04 Sewage Pumping StationsPIPA-OP010A:Part 1 Polyethylene Pressure Pipes Design for Dynamic StressesPower Piping ASME B31.1Process Piping ASME B31.3Pipeline Transportation Systems for Hydrocarbons and other Liquids ASME B31.4Refrigeration and Heat Transfer Components ASME B31.5Building Servic

6、es Piping ASME B31.9Slurry Transportation Piping Systems ASME B31.11Glass-reinforced plastics (GRP) piping ISO 14692-3Design & Construction of GRP Pipes BS 7159AWWA Fibreglass Pipe ANSI/AWWA C950第3頁，共32頁。There are two categories of damage that arise from surge eventscatastrophic failure of the pipel

7、ine system or equipmentfatigue failure of the pipeline, supports , instrumentation, equipment and components第4頁，共32頁。Equipment and Processes SolutionsStronger pipework to withstand the pressure surgeRerouting pipingChange of pipe material to one with a lower modulus (i.e. thermoplastic pipe material

8、s)Flow control valvesAir/Vacuum Release valvesIntermediate check valvesNon slam check valvesBypass ValvesGas accumulatorsLiquid accumulatorsSurge tanksSurge shaftsSurge anticipation valvesRelief valvesBursting discsWeak pipe sectionsIncrease diameter of pipeline to reduce average velocityVariable sp

9、eed drivesSoft startersValve closure and opening timesIncreasing the inertia of pumps and motors (i.e. flywheels or by selection)Minimising resonance hazards and increase reliability by additional supportsInvestment in more engineering第5頁，共32頁。Selection Process第6頁，共32頁。Piping Design Using Stronger P

10、ipe or Re-Routing the PipelineUse of Stronger PipeworkIncrease in capital costs for pipe, fittings, valves and instrumentsIncrease in velocity and celerity as wall thickness increasesIncrease likelihood of fatigue damage and maintenance costs if surge events frequentPipe inherently maintenance free

11、compared to other surge devicesNeeds to be determined at design stageRe-Routing PipelineIncrease in capital costsLand or easement acquisitionDirection drillingIncreased length of pipelineHydraulic grade line above the pipeline profile reduces potential for cavitationPossible increase in energyInhere

12、ntly maintenance freeNeeds to be determined at design stage第7頁，共32頁。Change of Pipe Material to One with a Lower Modulus (i.e. thermoplastic pipe materials)Capital cost neutralNot a universal solution because of limited pressure classes availableThermoplastic pipe materials properties vary with tempe

13、rature, strain rate and timeDoes not protect when column separation occursWall thickness selection to allow for vacuum conditionsLocal buckling at above ground supports to be designedNeeds to be determined at design stage第8頁，共32頁。Flow Control ValvesModerate capital costIncreased maintenance to ensur

14、e they remain effectiveCan be used for multiple duties and scenariosPower or instrumentation not necessarily requiredCan be retrofitted第9頁，共32頁。Air/Vacuum Release ValvesIncreased capital costsIncreased maintenance to ensure effective operationUse requires extensive modelling to ensure operation in a

15、ll scenariosNot suitable for hazardous liquidsPrimary duty is for line filling and draining and hence location may not be optimal for surge mitigationNot all air valves are suitable for this purpose due to their original designValve pit may be in road causing problems during construction or maintena

16、nceCan be retro fitted easily if reducing tees in pipeline already installed otherwise tee type couplings required to be fitted第10頁，共32頁。Modern Design of Air / Vacuum Release Valve-Ventomat第11頁，共32頁。Intermediate Check ValvesIncrease in capital costs for check valve but reduction in rating of other p

17、ipeline componentsEffective in splitting the surge pressure rise in twoDegree of increase in maintenance minimalProtects pumps from highest peak pressureNon slam check valves preferredValve pit may be in road way causing traffic problems during construction or maintenanceCheck valves are not conside

18、red an adequate form of isolation and hence should be installed with isolation valvesNeeds to be determined at design stage otherwise pipeline needs to be out of service for retrofitting check valve第12頁，共32頁。Non Slam Check ValveCapital cost increaseFast closing valve reduces surge pressure at pumpRe

19、duces fatigue damageIncrease in maintenance lowInherently trouble freeAvailable as short or long patternUsed extensively in EuropeCan be retrofitted as valves standard lengths第13頁，共32頁。Comparison of Check Valve Performance第14頁，共32頁。Noreva Annulus Type Non Slam Check Valves第15頁，共32頁。Bypass Check Valv

20、esIncrease capital costIncrease maintenance to ensure effective operationNeeds positive pressure upstream to provide energy to fill cavitation voidsSimple and effective for overcoming negative pressuresDoes not provide protection for positive pressuresCan be readily retrofitted第16頁，共32頁。Bladder Type

21、 Gas AccumulatorIncreased capitol costsMaintenance level low for bladder type Provides secure protection for positive and negative surge pressuresBest located at source of pressure transient eventOverseas design and manufactureCan be retrofitted Long lead time第17頁，共32頁。Hydro-Pneumatic AccumulatorInc

22、reased capital costsMaintenance level high for hydro pneumatic typeBest located at source of pressure transient eventProvides secure protection for positive and negative surge pressuresLocal design and manufactureCan be retrofitted if branched tees fitted to pipeworkLong lead time第18頁，共32頁。Liquid ac

23、cumulatorsIncrease capital costDifficult to model without test dataInherently maintenance freeCan be retrofitted but generally a long lead time第19頁，共32頁。Surge Tanksand Surge ShaftsCommonly used in water transmission systemsProvides protection from negative pressure events but NOT for positive pressu

24、resInherently maintenance free except for refilling facility of surge tankTelemetry required for monitoringCan be retrofitted but generally a long lead time required第20頁，共32頁。Surge Anticipation ValvesModerate capital costComplex devices Require power in the form of electric, hydraulic or pneumatic t

25、o operateDo not cover all surge events in a pipeline systemsHigh maintenance to ensure that they work when neededVendors who perform surge analysis and recommendation are NOT necessarily design engineers and do NOT take responsibility. Often do not have latest, or have limited capability, software.C

26、an be retrofitted however moderate lead times第21頁，共32頁。Relief Valvesand Bursting DiscsIncrease in capital costConventional devices do not react quickly enough to prevent damage from surge pressureDo not protect against vacuum conditionsHigh level of maintenanceBursting discs require replacement afte

27、r operationNeed for registration and routine testing per CodeSuitable for lethal and flammable liquids as part of an overall protection strategyCan be retrofitted however may be moderate lead times第22頁，共32頁。Weak Pipe SectionsCapital cost neutralReduces celerity in sensitive sectionsReduced surge pre

28、ssure magnitudeReduced fatigue damageCould be damaged by vacuum conditionsSuitable for low pressure systems in the water industryInherently maintenance freeNot a universal solutionNeeds to be determined at design stage第23頁，共32頁。Increase Diameter of Pipeline to Reduce Average VelocityReduced celerity

29、 and surge pressureIncrease in capital cost of pipe, excavation, valves and instrumentsIncreased life of the assetFuture augmentation possibleInherently maintenance freeReduction in energy of pumpingSettling of solids more likelyNeeds to be determined at design stage第24頁，共32頁。Variable Speed Drivesan

30、d Soft StartersIncrease in capital costs and complexityLow level of maintenanceIncreased frequency of replacement and upgradeProvides NO protection for loss of power scenariosSoft starters protect power supply more than pipeline; there are NO guarantees they can be set to limit surge pressuresReduce

31、d fatigue issues for normal stop/startLarger switchroom required to house devicesNeeds to be determined at design stage as costly to retrofit and to house in a switchroom第25頁，共32頁。Valve Closure and Opening TimesLow capital cost solutionCan be effective in reducing surge pressuresRequires power suppl

32、y in the form of hydraulic, pneumatic or electrical energy to be totally reliableNeeds uninterruptible power supply for secure operationRequires extensive modelling to cover all operational scenariosRequires routine testing to be effectiveCan be modified during commissioning or operation if valves a

33、re automated and fitted with adjustable opening/closing devices第26頁，共32頁。Increasing the Inertia of Pumps and MotorsModest increase in capital cost Flywheels increase moment of inertiaFour pole speed motors and pumps have larger moment of inertia and have other benefits over two pole motor driven pum

34、psPhysically larger pump sets and hence buildings may be increased in sizeInherently a low maintenance solutionNeeds to be determined at design stage第27頁，共32頁。Minimising Resonance Hazards and Increase Stiffness by Additional SupportsMinimise ResonanceIncreased capital costsIncreased engineering to determine dynamic behaviour of piping