What does the injection and stripping point hydraulics calculator do?

This calculator analyzes hydraulic effects when liquid is injected or stripped at a pipeline midpoint. It determines mixed fluid properties, velocity changes, and upstream/downstream pressure profiles using Darcy-Weisbach friction loss.

How are mixed fluid properties calculated at an injection point?

Mixed specific gravity is calculated by volume-weighted average: SG_mix = (Q₁×SG₁ + Q₂×SG₂)/(Q₁ + Q₂). The calculator also computes the resulting downstream velocity and Reynolds number changes.

What is the difference between injection and stripping operations?

Injection adds fluid at a midpoint, increasing downstream flow rate and potentially changing fluid properties. Stripping removes fluid, decreasing downstream flow. Both operations affect pressure profiles, velocities, and friction losses upstream and downstream.

Why must the pipeline be analyzed as two separate sections?

Injection or stripping creates a hydraulic discontinuity where flow rate, velocity, and fluid properties change. Treating the pipeline as a single section produces incorrect pressure drop and velocity calculations downstream of the connection point.

What is erosional velocity and why does it matter at injection points?

Erosional velocity is the maximum allowable velocity before pipe wall damage occurs, calculated per API RP 14E as Ve = C/√ρ. At injection points, increased downstream flow can push velocity above erosional limits, requiring larger downstream pipe diameter.

Injection & Stripping Point Hydraulics Calculator

Operation Type

Injection Stripping

Upstream Fluid

Fluid Preset

Specific Gravity

Viscosity

Injection Fluid

Fluid Preset

Specific Gravity

Viscosity

Flow Parameters

Upstream Flow Rate

Injection Rate

(same unit)

Inlet Pressure

psig

Pipe Parameters

Pipe Inner Diameter

Downstream Pipe ID

Absolute Roughness

Pipeline Geometry

Upstream Length

miles

Downstream Length

miles

Upstream Elevation Change

Downstream Elevation Change

📚 Learn the Theory

Understand injection and stripping point hydraulics, fluid mixing, and pressure profile analysis

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Results

Enter pipeline and fluid parameters, then click Calculate.

Formula Reference

Darcy-Weisbach:

ΔP = f(L/D)(ρV²/2gc)/144

Volume Mixing (SG):

SG_mix = (Q₁·SG₁ + Q₂·SG₂)/(Q₁ + Q₂)

Velocity:

V = 0.4085·Q/d²

Standards: Darcy-Weisbach, Colebrook-White (1939), Crane TP-410

Injection & Stripping Point Hydraulics Calculator

Operation Type

Upstream Fluid

Injection Fluid

Flow Parameters

Pipe Parameters

Pipeline Geometry

📚 Learn the Theory

Results

Formula Reference

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