Pressure Relief Tool
The Pressure Relief Tool is a professional API 520 sizing and verification application for engineers. It performs gas, liquid and steam relief calculations, integrates thermodynamic property estimation using the Peng–Robinson equation of state and IAPWS steam tables, and provides comprehensive reporting suitable for review.
Available on Google Play
Designed for process engineers working in the office or in the field.
01
Specify the Relief Conditions
Enter relieving pressures, temperatures, flow rate and factors/coefficients using an interface designed specifically for engineers
02
Build the Process Fluid
Select pure components or define complex mixtures. Thermodynamic properties are calculated automatically using the Peng–Robinson equation of state and the UNIFAC model
03
Calculate Relief Requirements
Determine required orifice area, flow regime, downstream temperature and API sizing with one tap.
Free vs Premium
Core relief-valve sizing is available free. Premium unlocks defined mixtures, advanced thermodynamic analysis and reporting.
| Feature | Free | Premium |
|---|---|---|
| Gas / vapour relief sizing & rating | ✓ | ✓ |
| Liquid relief sizing & rating | ✓ | ✓ |
| Steam relief sizing & rating | ✓ | ✓ |
| API 520 sizing calculations | ✓ | ✓ |
| API 526 orifice selection | ✓ | ✓ |
| SI & Imperial units | ✓ | ✓ |
| Manual property inputs | ✓ | ✓ |
| Define multicomponent mixtures | — | ✓ |
| Phase checks for defined fluids | — | ✓ |
| Phase-boundary data for defined mixtures | — | ✓ |
| Generate and share PDF reports | — | ✓ |
Premium includes a 7-day free trial, with monthly and annual subscriptions available through Google Play.
Technical Capabilities
Relief Modes
- ✔ Gas / Vapour Relief
- ✔ Liquid Relief
- ✔ Steam Relief
- ○ Two-phase relief sizing – Coming Soon
Thermodynamics
- ✔ Peng–Robinson Equation of State
- ✔ UNIFAC activity coefficient model
- ✔ IAPWS-IF97 Steam Properties
- ✔ 432 Compound Database
- ✔ User-defined physical properties
Outputs
- ✔ API 526 orifice sizing
- ✔ Compressibility factor
- ✔ Joule–Thomson cooling
- ✔ Thermodynamic phase checks for defined fluids
- ✔ Generate and share PDF reports
General
- ✔ SI & Imperial Units
- ✔ Offline operation
- ✔ Flow area & rating mode
Engineering Notes
- Two-phase relief sizing is not currently implemented
- Flashing calculations assume isenthalpic expansion
- Physical property correlation equations and parameters are from the ChemSep database
- Peng–Robinson binary interaction parameters are based on the ChemSep dataset
- Atmospheric pressure is taken to be 101.325 kPa
Version History
A concise record of updates to the Pressure Relief Tool. Only meaningful engineering changes are listed.
- v1.0.0 — Initial release. Includes relief valve sizing, report generation and sharing, unit conversions, and offline operation.
Future updates will be documented here as new tools and features are released.
Get the App
Ready to simplify pressure relief calculations?
Engineering Notice: Pressure Relief Tool is intended for use by competent engineering professionals. Users are responsible for independently reviewing all calculations before applying them in practice.
