Columns Heat Exchangers Separators Piping Control Valves Flow Meters Relief Systems

Relief Systems

ProMax® Sour Water Stripper

Let ProMax help you accurately size your relief valves, allowing you to protect equipment from excessive overpressure, while avoiding issues with excessive flow rates, including: possible valve damage, impaired performance, undersized discharge piping and effluent handling systems, and higher costs.

Many scenarios can result in an increased vessel pressure, including run-away reactions, loss of cooling, thermal expansion of liquids, or an external fire. In any of these scenarios, the pressure will increase until a predetermined relief pressure is reached, at which point the relief pressure valve will be open, decreasing the pressure after the turnaround time.

Once the scenario is identified, an appropriate relief type must be selected, as sizing depends on the type of relief device selected. ProMax supports sizing the following:

ProMax provides for reliable and proper sizing of a safety relief valve by giving you:

ProMax® Sour Water Stripper ProMax® Sour Water Stripper

Single and Two-phase flows are supported

Both single and two-phase flows are frequently encountered in various relief scenarios. Due to the large number of variables associated with the fluid properties, distribution of fluid phases, interaction, and transformation of the phases, sizing a two-phase relief scenario is considerably more complex than single-phase. A tool that can accurate handle these variables is important. ProMax supports:

ProMax® Sour Water Stripper

Relief Valve Standards

There are many different standards for Relief Valve Sizing, each applying different assumptions, thus giving different results. ProMax currently supports six different sets of Relief Valve Sizing Standards:


There are many scenarios that can lead to a dangerous increase in pressure of a vessel: valve failures, utility failures, cooling water problems, broken fans, electric failures, reflux failures, abnormal heat input from boilers, process control failure on reactors or cryogenic fluids, and many others. Often, the material in the vessel has a wide range of boiling points, or a liquid phase only covers a portion of the vessel. The ProMax Depressurization Tool, available in the ProMax® Property Stencils for all clients, provides a method to study scenarios where changes over time significantly affect the relief requirements.

The ProMax Depressurization Tool will help you quickly:

This tool applies to streams, separators, pipelines, and columns in your ProMax project, allowing you flexibility to model what is needed. ProMax will estimate the vessel volume for most cases, can estimate a fire heat input based on API 521 methodology, and supplies typical default values for many parameters, helping you quickly get to the results you need.

ProMax® ProMax-Pressure-Temp-Profile

Once you have obtained your results, you can easily copy the information from the tables into Excel for further evaluation or plotting.

ProMax Pressure Excel1 ProMax Pressure Excel2