Flow Measurement · Free Calculator
Erosional Velocity Calculator (API RP 14E)
Find the maximum velocity to avoid erosion in process lines with the API RP 14E formula, and check your actual velocity against it.
API RP 14EErosionTwo phase linesVelocity limit
Erosional velocity18.19 m/s (59.66 ft/s)
Actual velocity13.52 m/s
Ratio actual ÷ erosional0.743
Maximum flow at erosional velocity538.1 m³/h
How this result was calculated
- Ve = C ÷ √ρ (ft/s, ρ in lb/ft³) → Ve = 1.22 × C ÷ √ρ (m/s, ρ in kg/m³)
- Ve = 1.22 × 100 ÷ √45 = 18.19 m/s
Advertisement
API RP 14E Erosional Velocity
Ve = C ÷ √ρm (Ve in ft/s, ρm in lb/ft³)
SI form: Ve (m/s) ≈ 1.22 × C ÷ √ρm (kg/m³)
SI form: Ve (m/s) ≈ 1.22 × C ÷ √ρm (kg/m³)
ρm is the gas, liquid or two phase mixture density at flowing conditions and C an empirical factor: 100 for continuous and 125 for intermittent service in solids free fluids. Higher values are sometimes justified with corrosion resistant materials; lower values apply where sand is present.
Worked example
A two phase mixture of 45 kg/m³ in continuous service has an erosional velocity of about 18.2 m/s. 400 m³/h in a 4" Sch 40 line flows at 13.5 m/s, below the limit.
Key insight: erosional velocity is a screening limit from API RP 14E for offshore production piping. It is conservative for clean gas and not conservative when sand is produced.
Advertisement
Frequently Asked Questions
What is erosional velocity?
The velocity above which erosion of the pipe wall is expected, estimated by API RP 14E from the fluid density.
Which C factor should I use?
100 for continuous service and 125 for intermittent service in solids free fluids, unless company standards specify otherwise.
Does it apply to liquids?
Yes, but for liquids other limits, such as noise and water hammer, usually govern first.
You May Also Like
Learn more on the blog
What factors affect the stability of flow meter readings?
A practical, field focused guide on instrumentationblog.in that explains the theory behind this calculator and how engineers apply it on real plants.
Read Full ArticleMore Flow Measurement Calculators
Orifice Plate Flow Calculator (ISO 5167)ISO 5167-2, Liquid and gasPipe Flow Velocity CalculatorNPS Sch 40 and 80, Flow to velocityReynolds Number CalculatorLaminar or turbulent, Velocity or flowFlow Meter K Factor CalculatorFrequency to rate, Pulses to totalOrifice Plate Bore Sizing CalculatorISO 5167-2, Bore and β ratioVenturi Tube Flow CalculatorISO 5167-4, Liquid and gasPitot Tube Velocity CalculatorDynamic pressure, VelocityWeir Flow CalculatorV notch, RectangularParshall Flume Flow CalculatorParshall flume, Free flowManning Equation Open Channel CalculatorManning n, Rectangular channelStandard to Actual Gas Flow CalculatorNm³/h, Sm³/hGas Density Calculatorρ = PM/ZRT, Molecular weightMass Flow to Volume Flow Calculatorkg/h to m³/h, m³/h to kg/hPipe Pressure Drop CalculatorDarcy Weisbach, Friction factorFlow Meter Turndown Ratio CalculatorTurndown ratio, DP metersMagnetic Flow Meter Sizing CalculatorDN 10 to DN 600, Velocity checkFlow Meter Straight Pipe Run CalculatorUpstream D, Downstream DFlow Totalizer and Fill Time CalculatorTotal volume, Fill timeFlow Nozzle Flow CalculatorISO 5167-3, ISA 1932Vortex Flow Meter CalculatorStrouhal number, K factorUltrasonic Transit Time Flow CalculatorTransit time, Clamp onRotameter Correction CalculatorVariable area, Liquid densityDP Flow Transmitter Rerange CalculatorSquare root law, Orifice and venturiGas Flow Pressure and Temperature CompensationDP meters, Pressure correctionPipe Sizing Calculator (Flow and Velocity)Flow to diameter, NPS Sch 40 and 80Darcy Friction Factor Calculator (Colebrook)Colebrook White, Swamee JainOrifice Permanent Pressure Loss CalculatorISO 5167-2, Permanent pressure lossTank Drain Time CalculatorTorricelli, Gravity drainPump Power CalculatorHydraulic power, Shaft powerFlow Meter Accuracy Calculator% of rate, % of full scaleRestriction Orifice Sizing CalculatorRestriction orifice, Choked gas flowGas Flow to Energy CalculatorCalorific value, kW and MMBtu/hTank Level Rate to Flow CalculatorLevel change, Net flowFlowmeter Bucket and Stopwatch Test CalculatorBucket test, Meter errorFlow Meter Factor and K Factor Correction CalculatorMeter factor, ProverPump Affinity Laws CalculatorAffinity laws, VFD speedNPSH Available CalculatorNPSHa, NPSHr marginCone (V Cone) Flow Meter CalculatorISO 5167-5, Cone meterAveraging Pitot Tube (Annubar Type) Flow CalculatorAveraging pitot, Flow coefficient KLaminar Flow Element and Capillary Flow CalculatorHagen Poiseuille, CapillaryRectangular Duct Flow and Hydraulic Diameter CalculatorHydraulic diameter, Equivalent diameterPitot Traverse Points and Average Velocity CalculatorLog Tchebycheff, Traverse pointsPartially Full Pipe Flow Calculator (Manning)Manning equation, Gravity sewerDP Flow Measurement Uncertainty Calculator (ISO 5167)ISO 5167-1, Uncertainty budgetGas Pipeline Pressure Drop Calculator (Isothermal)Compressible flow, IsothermalHazen Williams Water Pipe Head Loss CalculatorHazen Williams, C factorPipe Flow Capacity from Pressure Drop CalculatorDarcy Weisbach, Allowable ΔPGas Velocity and Mach Number CalculatorActual velocity, Mach numberChemical Dosing Pump CalculatorDose rate, ppm (mg/L)Flow Rate Unit Converterm³/h, GPM, L/min, CFM
More Calculator Categories
Temperature Measurement26 live toolsInstrumentation Signal13 live toolsPLC Digital Signal12 live toolsLevel Measurement24 live toolsPressure Measurement24 live toolsControl Valve17 live toolsCalibration16 live toolsSafety and SIL16 live toolsAnalytical18 live toolsElectrical37 live toolsElectronics35 live toolsUnit Converters76 converters, 700+ units