Introduction
The equation for wave speed can be expressed in this general form.
a = \frac{\sqrt{\frac{K_S}{\rho}}}{\sqrt{1 + \left(\frac{K_S}{E}\right)\left(\frac{D}{t}\right) m}}
a = \frac{\sqrt{\frac{K_S}{\rho}}}{\sqrt{1 + \left(\frac{K_S}{E}\right)\left(\frac{D}{t}\right) m}}
Where:
π β Wave Speed
πΎπ βAdiabatic Bulk Modulus of fluid
π β Density of fluid
πΈ β Modulus of Elasticity for Steel Pipe (psi)
π· β Pipe Diameter (in)
π‘ β Pipe Wall Thickness (in)
π β Poissonβs Ratio (0.30 for Steel)
π β Coefficient for type of pipe support
- Pipe anchorage only at the upstream end = (5/4βπ)
- Pull pipe restraint from axial movement = (1βπ2)
- Longitudinal expansion joints along the pipeline = (1.0)
K_s = A + B(P) – C(\sqrt{T}) – D(AP I) – E(AP I^2) + F(T)(AP I)
K_s = A + B(P) - C(\sqrt{T}) - D(AP I) - E(AP I^2) + F(T)(AP I)
Where:
πΎπ β Adiabatic Bulk Modulus
π β Pressure (psig)
π β Temperature (Β°π
) = (β+460)
π΄ππΌ β API gravity of liquid @ 60β
π΄ = 1.286×106
π΅ = 13.55
πΆ = 4.122×104
π· = 4.53×103
πΈ = 10.59
πΉ = 3.228
K_s = (1.286 \times 10^6) + (13.55\times P) – (4.122 \times 10^4 \times\sqrt{T}) – (4.53 \times 10^3\times A) – (10.59\times A^2) + (3.228 \times T \times A)
K_s = (1.286 \times 10^6) + (13.55\times P) - (4.122 \times 10^4 \times\sqrt{T}) - (4.53 \times 10^3\times A) - (10.59\times A^2) + (3.228 \times T \times A)
Case Guide
Part 1: Create Case
- Select the Wave Speed in Pipelines application from the PLTB Misc. Module
- To create a new case, click the βAdd Caseβ button
- Enter Case Name, Location, Date and any necessary notes.
- Fill out all required Parameters.
- Make sure the values you are inputting are in the correct units.
- Click the CALCULATE button to overview results.
Input Parameters
- Pipe Type
- Nominal Pipe Diameter (in)
- Outside Pipe Diameter (in)
- Nominal Wall Thickness (in)
- Reduced Wall Thickness (in)
- Internal Pipe Diameter (in)
- Liquid Temperature (Β°F)
- Product Type
- Liquid Specific Gravity
- Pressure (psi)
Part 2: Outputs/Reports
- If you need to modify an input parameter, click the CALCULATE button after the change.
- To SAVE, fill out all required case details then click the SAVE button.
- To rename an existing file, click the SAVE As button. Provide all case info then click SAVE.
- To generate a REPORT, click the REPORT button.
- The user may export the Case/Report by clicking the Export to Excel icon.
- To delete a case, click the DELETE icon near the top of the widget.
Results
- Adiabatic Bulk Modulus (psi)
- Wave Speed in Pipeline (ft/sec)
References
- Hydraulics for Pipeliners β C.B. Lester
- API standard 2540 Manual of Petroleum Measurement Standards, Chapter 11.1-Volume Correction Factors, Volume X – Background, Development, and Program Documentation.
- API RP 1117 Movement of In-Service Pipeline