Posts
Thermal Relief Cascades @ Neutrium.net
January 27, 2014For 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.
Baume Scale @ Neutrium.net
January 22, 2014The 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 Today it is largely superseded, however it is still used in some industries as a measure of density or concentration.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 @ Neutrium.net
January 21, 2014API 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 Flows @ Neutrium.net
January 20, 2014For 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.
Calculating Interface Volumes for Multi-product pipelines @ Neutrium.net
November 13, 2013Due 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.
Estimating the viscosity of a mixture. @ Neutrium.net
October 22, 2013For 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 @ Neutrium.net
October 16, 2013This 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.
Pump moment of inertia @ Neutrium.net
October 9, 2013The moment of inertia of a pump is its resistance to changes in angular velocity as it rotates about its shaft. Knowledge of the moment of inertia of a pump, motor and associated components is typically required for transient analysis of a pumped system. This article presents methods by which pump and motor moment of inertia may be estimated.
Torque and Electric Motors @ Neutrium.net
September 27, 2013Torque is an important parameter in ensuring motors are well suited to their intended service. This article demonstrates how to calculate torque for a given motor or drive, and provides a brief introduction to motors and torque.
Terminal Velocity of Particles for Gravity Separation @ Neutrium.net
September 7, 2013There are many operations in which two phases must be separated. These separations may be gas-liquid, gas-solid, liquid-liquid or liquid-solid, with several factors such as relative densities, gravity, fluid velocities and the shape of particles and/or droplets influence the phase separability. In this article we present the fundamentals of these separations and provide the Stoke’s, Intermediate and Newton’s formulae for calculating the terminal velocities of settling particles to analyse separation systems.