surge analysis
DESCRIPTION
HDPE Pressure Pipe Occasional & Recurring Surge analysisTRANSCRIPT
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HDPE Pressure Pipe Occasional and Recurring
Surge Design ConsiderationsMark Knight PhD, P. Eng.
University of Waterloo
Camille George Rubeiz, P.E.Plastics Pipe Institute
Larry Petroff, P.E.Plastic Pipe Consultant
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Developers of Industry Leading Design Tools BOREAID
Full commercial licenced HDD design tool Fall 2013 a Vermeer Product
free web based HDD PE pipe design tool limited version of BOREAID
free web based HDPE and PVC pressure pipe calculator that follows ASTM and AWWA standards
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Disclaimers
I am a product independent academic and researcher
I am not paid to represent any pipe manufacturers or suppliers
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Confused Plastic Pipe Industry
Different terminology for HDPE and PVCPressure Class (PC) vs Pressure Rating (PR)DIOD, CIOD, IPS, DIPS
HDPE vs PVC marketing
Lack of industry understanding of ASTM and AWWA design methods
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HDPE and PVC Pressure Pipe Design Standards
ASTM F714
AWWA C901 AWWA C906
AWWAC900/C905
PE3608 PE3608 PE3608 PVC12454PE 4710
@ 1000 psiPE 4710
@1000 psiPE4710 @800 psi
PVC12454@ 2000 psiPVC12454
HDPE Pipe Resin = PE3608 and PE4710PVC Pipe Resin = PVC12454
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Plastic Pressure Pipe Design
Complete Life Cycle Design Analysis
Fatigue Determine No. of cycles to failure over design life
Complete Operational Design
Working and Surge Pressure Analysis
PIPE Design Input Properties
Velocity Min ID Flow Pressure Disinfectant
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Working Pressure Design
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Hydrostatic Design Stress (HDS)
HDPE PVCASTMF714
AWWAC901
AWWAC906
AWWAC900/C905
PE4710 1000psi 800psi
PE3608 800psi
PVC12454 2000psi
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Pressure Class (PC) @ 73oF
PC = 2 HDS/(DR-1)
HDS = Hydrostatic Design StressDR = Dimension Ratio = OD/tmin
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Allowable Pressure Design
HDPEAWWA M55
PVC AWWA
C900/C905WPR PC x FT
WPR + Pos 2.0 x PC x FT 1.6 x PC x FTWPR + PRS 1.5 x PC x FT PC x FT
WPR = Working Pressure RatingPOS = Occasional SurgePRS = Recurring Surge
Temperature Factors (FT)
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Temperature Factors (FT)
HDPEAWWA M55
PVC AWWA
C900/C905FT
Continuous Long-Term Temperature FT
1.0 < 81oF 80oF 0.880.9 81 90oF 90oF 0.750.8 91-100oF 100oF 0.62
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Allowable Design Pressure ExamplePC = 2 HDS/(DR-1)
HDPE DR-17
PVC DR-18
ASTM F714
AWWA C901
AWWA C906
AWWA C900C905
PE 4710 125 psi 100 psi
PE 3608 100 psiPVC
12454 235 psi
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Surge Design (Wing Flex Design)
What are the major design Issues for Wing design?
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TypicalPressureFluctuationfromSuddenValveClosureinDR11Pipe
LoadRate~120psig/sec
G.P.Marshall,S.Brogden,M.A.Shepherd(1998)EvaluationoftheSurgeandFatigueResistanceofPVCandPEPipelineMaterialsforuseintheU.K.WaterIndustry,
PlasticsPipeX,Goteburg,Sweden
Time(seconds)
Pressure(bar)
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Surge Design
Design system such that it can withstand the highest expected surge load event over its
design life
While a full transient analysis is recommended, a full flow stoppage at the max. flow velocity provides a good basis for considering surge
events.
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Surge - Analysis
Joukowsky Equation: Ps = a(V/2.31g)
Ps = surge (psi)a = wave velocity (ft/s)V = change in velocity (fps)g = acceleration due to gravity (32 ft/sec2)
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What are Typical Network Water Velocities?
Jana Lab survey of 51 water utilities determined: Average Maximum Design Velocities for Normal Flow Average Maximum Design Velocities for Fire Flow
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Jana Lab Water Velocity Survey
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5
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1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51
Maximum Design Velocity for Normal Flow
(fps)
Average = 6.7 fps
http://plasticpipe.org/pdf/mid-fatigue-plastic-water-pipe-01-12-12
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Fatigue Design
Recurring surges:
frequently occurring surges caused by normal pipe operations like opening and closing of pumps and valves, AWWA PE M55
may occur up to millions of times in a piping systems lifetime AWWA PVC C905-10
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Fatigue Design
Occasional surges:
Caused by emergency operations
Often the result of a malfunction, such as a power failure or system component failure AWWA PE M55
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PVC Fatigue Design
PVC design fatigue life is determined using AWWA C900 and C905 Appendix B.
Well established method but not well understood in the industry.
Often not performed due to analysis complexity and lack of industry understanding
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PVC Fatigue Design
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HDPE Fatigue Design Fatigue surge pressure analysis in AWWA M55
Fatigue life method is not in current AWWA M55 (typically, not a limiting factor)
Fatigue life method will be implemented in revised AWWA M55
PE 3608 / PE 4710 design fatigue life can be determined using fatigue curves provided in Marshall, G.P., Brogden, S: Final report of Pipeline Innovation Contract to UKWIR, 1997.
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HDPE Fatigue DesignPPI-PACE methodology implemented from: AWWA M55-2005, PE Pipe Design and Installation Jana Lab, 2012, Fatigue of Plastic Water Pipe: A
Technical Review with Recommendations for PE4710 Pipe Design Fatigue
PE4710 fatigue S-N curves data from: Resistance of PE4710 Piping to Pressure Surge Events
in Force Main Applications, PP XVI, Barcelona, 2012
UK Water Industry IGN 4-37-02 Design Against Surge and Fatigue Conditions for Thermoplastic Pipes
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Test Specimens Cycles at 1.5 x PC(Recurring Surge)
Status
Straight Pipe11,213,023
NoFailures
10,038,073
6,754,833
Pipe with butt-fused joint
10,952,363
11,017,153TestsconductedbyJanaLabsSeeCrabtreeetal.,PPXVI,2012
Aftercompletionpipescycledfrom0to2xPCfor2739to6665cyclesnofailures Showslotsofliferemaining
PE4710RecurringSurgePipeTests(cycles0to1.5xPC)
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Jana4testsat1500psi
G.P.Marshall,S.Brogden,M.A.Shepherd(1998)EvaluationoftheSurgeandFatigueResistanceofPVCandPEPipelineMaterialsforuseintheU.K.WaterIndustry,
PlasticsPipeX,Goteburg,Sweden
StressforPE4710at1.5x PC=1500psi(10.34MPa)
1450psi
NumberofCyclestoFailure
1st GenerationPE
4thGenerationPE
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http://ppipace.com/
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PPI-PACE: Purpose
1. Developauserfriendly,free&onlinepipesoftware
2. Provideprelim.calculationsforoperatingpressure,surgepressureandfatiguedesignlife.
3. Assistdesignersandownersintheevaluationofplasticpipeforwaterdistribution,transmissionandforcemains
4. Implementexistingstandardsandmethods:AWWAC900/C901/C905/C906,M55andASTMF714/D2241.
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PPI-PACE Defaults
Default Allowable RangeRecurring Surge Velocity
5 fps 4 8 fps
Occasional Surge velocity
8 fps 5 - 15 fps
Working Pressure
70 psi 40 psi (min.)
Anticipated Surges per day
55 cycles
Temperature 57 oF 40-100 oFMin. Design Life 100 years 50 (min.)
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UNI-BELL and PPI-PACE
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Design Example
18 inch DIPS/CIOD 160 psi Operating Pressures 4.0 fps Recurring Flow Velocity 7 fps Occasional Flow Velocity 57oF Temperature 100 Year Design Life 55 cycles/day = approx. 2 million cycles/100 yrs
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Uni-Bell Design Example
1. Why HDPE DR 7.3? DR 13.5 (PC 160) is OK
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PE 4710 DR 13.5 (PC 160) OK
PE 3608 DR 13.5 (PC 128) NG
PVC DR 14 (PC 305) NG
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PE 4710 DR 13.5 (PC 160) OK PE 3608 DR 13.5 (PC 128) NG
PVC DR 14 (PC 305) NG
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Summary HDPE and PVC are both good materials
According to existing approved design standards HDPE has much fatigue life than PVC
PPI-PACE provides a simple, easy to use plastic pipe design tool that follows existing design standard methodologies
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