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Neutrium is a knowledge base of engineering topics, centred mainly around chemical engineering design challenges faced by engineers in their daily work. We created Neutrium to bridge the gap between theory and practice. Feel free to ask a question, leave feedback or take a look at one of our in-depth articles.

Thermal Relief Cascades
Thermal Relief Cascades

For systems where liquid product may be trapped in a pipe section of an extended period of time thermal expansion can become a problem. Heating of the fluid in the pipe results in a rapid pressure rise as the fluid expands which can quickly exceed the design pressure of the pipeline. The damaging effects of the thermal expansion can be mitigated through the use of thermal relief valves and where there is several potential pipe blockages in series, it is often necessary to ‘cascade’ thermal relief valves back to a tank. This article describes how to design a cascading thermal relief system.

Baumé Scale

The Baumé scale was first developed in 1768 as a method of measuring the density of liquids. Today it is largely superseded, however it is still used in some industries as a measure of density or concentration. This article presents formula for the calculation of degrees Baumé for a liquid.

API Gravity

API gravity is measure of the density of liquid hydrocarbons relative to water. This article provides a reference to the API gravity calculation formula and some typical values of API gravity for common hydrocarbons.

Calculating Thermal Relief Flow Rates

For long sections of pipe, the thermal expansion of trapped liquid can be significant. It is often required that the increase in volume of the fluid be determined in order to select suitable thermal relief valves to protect the integrity of the pipework. This article details how to calculate the required relief flow rate to prevent over pressure due to thermal expansion.

Flash Steam
Flash Steam

When condensate is discharged from a high pressure steam system to a system of lower pressure, a proportion of the condensate may vaporise to form low pressure steam. This is known as flash steam and may be utilised in low pressure heating systems to improve plant efficiency. This article discusses the generation of flash steam and presents a method by which it can be quantified.

Calculating Interface Volumes for Multi-product Pipelines
Calculating Interface Volumes for Multi-product Pipelines

Due to their large capital expense, pipelines are often utilized for the transfer of multiple products. During operation of these multi-product pipelines, the interface between two adjacent products extends (referred to as interface mixing), resulting in the contamination of each product. This interface is typically sent to slops collection for reprocessing or disposal at additional cost to the operator. Therefore the economics of a pipeline can often be improved through a study of product interfaces under various operational conditions to aide in the minimization of interface mixing. This article presents several empirical methods by which interface mixing can be quantified.

Thermal Conductivity of Metals and Alloys

This article provides thermal conductivity data for a selection of metals and alloys. Thermal conductivity measures a materials ability to allow heat to pass through it via conductance.

Thermal Conductivity of Common Materials

This article provides thermal conductivity data for a selection of common materials. Thermal conductivity measures a materials ability to allow heat to pass through it via conductance.

Estimating the Viscosity of Mixtures

For some engineering calculations, particularly in hydrocarbon processing, it is necessary to estimate the viscosity of a mixture (blend) of two or more components. This article presents the Gambill and Refutas methods, which are commonly used in petroleum refining for predicting the viscosity of oil blends.

Relief Valve Orifice Area to API RP 526

This article lists the standard effective orifice areas for the orifice designations found in API RP 526 5th edition. These orifice designations set the minimum effective orifice area which a relief valve must have to meet the API 526 requirements and must be used with the sizing equations in API RP 520 Part I.