Pressure Relief Tool

Pressure Relief Tool (PRT) is a convenient engineering utility designed for process, mechanical, and safety engineers.

PRT allows users to quickly assess the adequacy of existing installations and prioritise borderline cases that require a more detailed, formal review. This targeted approach boosts the efficiency and promptness of safety reviews and minimises risk to processing plants.

PRT offers sizing, rating and API 526 selection based on industry-standard API 520 Part I methodologies.

Free Features:
Size new relief valves or rate the capacity of existing ones for:

Gas & Vapour Relief
Liquid Relief
Steam Relief

Unit Flexibility: Easily switch between Metric (SI) and Imperial (USCS) units; the mixing of units is supported. User inputs are automatically converted to the basis required by API 520 equations.

Data persistence allows users to switch between calculators without losing previously entered data.

Premium Features:
Unlock the full power of PRT with a Premium subscription. Premium includes all Free features plus :

Component and Physical Property Database - Access the thermophysical properties of 432 compounds and load fluid compositions for challenging calculations.
Gas/Vapour Relief - Calculate molecular weight (M), the ratio of specific heats (k) and compressibility (Z) using the Peng-Robinson Equation of State. The Joule-Thomson cooling of the outlet stream is calculated (for information).

Liquids - Industry standard mixing rules are used to calculate specific gravity and viscosity of either pure liquids or mixtures.

Steam - Steam properties are derived from IAPWS-IF97 steam table equations; however, superheat factors are interpolated from data tabulated in API 520.

Two-Phase Flash Diagnostics - Built-in checks to identify if your inlet and/or outlet conditions are invalid, i.e. two-phase state in the inlet at the specified conditions. PRT also checks the outlet for possible condensation due to JT-cooling (gas/vapour) or flashing (liquid).

These checks are only available on the gas/vapour relief and liquid relief calculators. Note also that two-phase sizing is not currently supported by PRT.

Text Reports - Generate text reports of your calculations, including all the relevant properties and correction factors. These reports are time-stamped and can be saved to your device for further review/analysis.

Share Results - Instantly export your calculation results via email or messaging apps to collaborate with co-workers or for export to external storage.

Whether you are working on site or at your desk, this app provides a robust thermodynamic engine to handle complex relief scenarios for Gas, Liquid, and Steam services.

Note: This tool is intended for use by qualified engineers as a design aid. Always verify final safety valve selections through a formal, peer-reviewed assessment, using the manufacturer’s certified data and local regulatory requirements.