Calculator Inputs
The page uses a stacked content layout, while the input grid shifts to three columns on large screens, two on medium screens, and one on mobile.
Example Data Table
| Parameter | Example Value | Unit | Purpose |
|---|---|---|---|
| Outer Diameter | 168.3 | mm | Outside pipe size used in the Barlow estimate. |
| Wall Thickness | 8.18 | mm | Nominal wall before corrosion deduction. |
| Corrosion Allowance | 0.50 | mm | Removes expected wall loss from the pressure calculation. |
| SMYS | 415 | MPa | Material strength used for yield-based burst screening. |
| UTS | 520 | MPa | Material strength used for ultimate burst screening. |
| Weld Efficiency | 1.00 | - | Adjusts for joint quality and fabrication condition. |
| Design Factor | 0.72 | - | Applies service conservatism to the estimate. |
| Operating Pressure | 8.00 | MPa | Compared against estimated burst values and margins. |
Formula Used
Net Wall Thickness
tnet = t - c
Where t is nominal wall thickness and c is corrosion allowance.
Yield Burst Pressure
Pyield = (2 × SMYS × tnet × E × F) / D
Where E is weld efficiency, F is design factor, and D is outer diameter.
Ultimate Burst Pressure
Pultimate = (2 × UTS × tnet × E × F) / D
This gives a higher screening estimate using ultimate tensile strength.
How to Use This Calculator
- Choose your preferred length, strength, and pressure units.
- Enter outer diameter and wall thickness using the same length unit.
- Add corrosion allowance to account for expected wall loss.
- Enter SMYS and UTS from the material specification.
- Set weld efficiency and design factor based on your project assumptions.
- Type the expected operating pressure and the hydrotest factor.
- Press the calculate button to show results above the form.
- Review yield burst pressure, ultimate burst pressure, margins, utilization, and assumption notes.
- Use the export buttons to save the calculated result as CSV or PDF.
Frequently Asked Questions
1. What does this calculator estimate?
It estimates burst pressure using pipe size, net wall thickness, material strength, weld efficiency, and design factor. It reports both yield-based and ultimate-based screening values.
2. Why are there two burst pressure results?
The yield result is more conservative because it uses minimum yield strength. The ultimate result uses tensile strength and typically produces a higher burst estimate.
3. Why subtract corrosion allowance?
Corrosion allowance reduces available wall thickness. Using net thickness helps reflect future deterioration and gives a more realistic screening pressure estimate.
4. What is weld efficiency?
Weld efficiency adjusts the estimate for joint quality. Lower values reduce calculated burst pressure and reflect weaker seam performance or reduced confidence in the weld.
5. Can I use inches and PSI?
Yes. The calculator accepts inches for dimensions and PSI for strength or output pressure. Keep diameter, thickness, and corrosion allowance in the same length unit.
6. Is this valid for thick-wall pipes?
It becomes less reliable as the wall gets thick relative to diameter. The calculator flags this condition, so you know when the thin-wall assumption needs caution.
7. What does utilization mean?
Utilization is operating pressure divided by the yield burst estimate. A higher percentage means the line is using more of its available burst margin.
8. Is this enough for design approval?
No. It is a fast engineering screening tool. Final approval should also consider applicable codes, temperature effects, defects, fatigue, fracture, and inspection data.