Sheet1PRESSURE DROP CALCULATION EQUATIONS FOR PIPING AND PIPELINE

Ajay S. Satpute Sr. Process EngineerM. Tech. (Chemical)I.I.T., Madras, INDIARamboll Oil & Gas, QATARIntroduction:This spreadsheet is the compilation of pressure drop calculation equations for piping and pipeline.The purpose of this exercise is to have most reliable equations for pressure drop calculations at one place.YELLOW boxes are for input parameters and BLUE boxes are the calculated values.PIPE SIZINGPIPE SIZINGPIPE SIZING

Single phase (Liquid)Single phase (Water)Single phase (Gas) ( 12")Single phase (Gas) (> 10")Single phase (Gas) (Near atmospheric operating pressure lines)Single phase (Steam)Two phase

Weymouth equationPanhandle equationSpitzglass equationBabcock equation Modified Darcy equationDarcy - Weichbach equation (Ref. Crane handbook, 1986)From WikipediaAPI 14E, 5th editionAPI 14E, 5th editionAPI 14E, 5th edition(From internet)API 14E, 5th editionWhere; Pressure drop in psi7.3HazenWilliams equationWhere;Gas flow rate in mmscfd1.074Where; Gas flow rate in mmscfd173.932DPipe ID in inch2 Erosional velocity equationDPipe ID in inch2DPipe ID in inch12Where; Gas flow rate in mmscfd0.0777WSteam mass flow rate in lb/hr1500API 14E, 5th editionWhere; Pressure drop in meter water column17P1Upstream pressure in psia100P1Upstream pressure in psia100Pressure drop in inch of water column10L'Pipe length in ft150LaminarTurbulentLPipe length in meter50P2Downstream pressure in psia90P2Downstream pressure in psia90DPipe ID in inch2'Steam density in lb/ft30.146Where; Pressure drop in psi/100 ft0.365QVolumetric flow rate in m3/s0.0058904862L'Pipe length in ft150Pipe length in miles0.028575SSpecific gravity of gas at standard condition1Erosional velocity in ft/s137.0CRoughness coefficient100SSpecific gravity of gas at standard condition1SSpecific gravity of gas at standard condition1L'Pipe length in ft150fMoody / Darcy friction factor0.02dPipe ID in meter5.00E-02ZCompressibility factor0.9961ZCompressibility factor0.9961WMass flow rate in lb/hr15000Haaland equation (approximation of Colebrook White equation)T1Gas inlet temperature in oR550T1Gas inlet temperature in oR550DPipe ID in inch6EEfficiency factor;1Average mixture density, lb/ft31Where; Pressure drop in Pa198,8511 for brand new pipeCEmpirical constant100Darcy friction factor0.0210.95 for good operating conditions100 for continuous serviceLPipe length in meter1000.92 for average operating conditions125 for non-continuous serviceVLiquid velocity in m/s3.4380.85 for unfavorable operating conditionsdPipe ID in meter5.00E-02Reynold's number137,520Relative roughness9.00E-04Liquid density in kg/m3800Note: Spitzglass equation can be used for piping and pipeline for single phase gas at near atmospheric operating pressure.Note: Babcock equation can be used for piping and pipeline for steam.Note: Modified Darcy equation can be used for piping and pipeline for two phase fluid.Liquid viscosity in Pa.s6.05E-04Note: Weymouth equation can be used for piping and pipeline for ID 12".Note: Panhandle equation can be used for piping and pipeline for ID > 10".

PIPELINE SIZINGPIPELINE SIZINGPIPELINE SIZING

Single phase (Crude oil)Single phase (Gas) ( 12")Single phase (Gas) (> 10")Single phase (Gas) (Near atmospheric operating pressure lines)Single phase (Steam)Two phase

Service pipeline company equation (Ref. IPS-E-PR-440, March 1996)Weymouth equationPanhandle equationSpitzglass equationBabcock equationModified Darcy equationAPI 14E, 5th editionAPI 14E, 5th editionAPI 14E, 5th editionAPI 14E, 5th edition(For DN 750) (For DN > 750)Where; Pressure drop in psi7.3Where;Gas flow rate in mmscfd1.074Where; Gas flow rate in mmscfd173.932DPipe ID in inch2Erosional velocity equationDPipe ID in inch2DPipe ID in inch12Where; Gas flow rate in mmscfd0.0777WSteam mass flow rate in lb/hr1500API 14E, 5th editionP1Upstream pressure in psia100P1Upstream pressure in psia100Pressure drop in inch of water column10L'Pipe length in ft150P2Downstream pressure in psia90P2Downstream pressure in psia90DPipe ID in inch2'Steam density in lb/ft30.146Where; Pressure drop in psi/100 ft0.365L'Pipe length in ft150Pipe length in miles0.028575SSpecific gravity of gas at standard condition1Erosional velocity in ft/s137.0(Laminar, if Nrem 0.135)(Turbulent)SSpecific gravity of gas at standard condition1SSpecific gravity of gas at standard condition1L'Pipe length in ft150fMoody / Darcy friction factor0.02ZCompressibility factor0.9961ZCompressibility factor0.9961WMass flow rate in lb/hr15000T1Gas inlet temperature in oR550T1Gas inlet temperature in oR550DPipe ID in inch6EEfficiency factor;1Average mixture density, lb/ft311 for brand new pipeCEmpirical constant1000.95 for good operating conditions100 for continuous serviceWhere; Pressure drop in kPa / 100 m267.90.92 for average operating conditions125 for non-continuous serviceLiquid flow rate in m3/hr24.30.85 for unfavorable operating conditionsKinematic viscosity, m2/s1.00E-05fFriction factor0.0068Pipe ID in mm50Modified Reynold's number2.2(NRem = NRe / 7742)SSpecific gravity of liquid0.8Note: Spitzglass equation can be used for piping and pipeline for single phase gas at near atmospheric operating pressure.Note: Babcock equation can be used for piping and pipeline for steam.Note: Modified Darcy equation can be used for piping and pipeline for two phase fluid.Note: Darcy-Weichbach equation can also be used for liquids in PIPELINE.Note: Weymouth equation can be used for piping and pipeline for ID 12".Note: Panhandle equation can be used for piping and pipeline for ID > 10".

Sheet2

Sheet3