# Welcome to Neutrium

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.

The 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.

Reading values from a graph or plot with a logarithmic axis visually is difficult and will often result in inaccurate readings. This article presents formulae which may be used with measurements from a graph axis to obtain more accurate values.

Pump Specific Speed, NS is a method of characterising a pump duty by head, flow rate and rotational speed. Pump specific speed may be used to determine an appropriate pump design for a given application when choosing between axial, radial or multistage centrifugal designs or positive displacement pumps.

As fluid flows through a packed bed it experiences a pressure loss due to friction. This article describes the use of the Carman-Kozeny and Ergun equations for the calculation of pressure drop through a randomly packed bed of spheres.

Birmingham Wire Gauge (BWG), also known as Stubs Iron Wire Gauge is a system of measurements describing thickness. BWG has been historically used to describe the outside diameter of small tubes and wires, as well as the wall thickness of some large tubes (such as those used within a shell and tube heat exchanger). This article presents length conversions for BWG values into metric and imperial units.

There 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.

Nominal Pipe Size (NPS) is a defined set of standard pipe sizes commonly used for process piping. NPS piping is defined in terms of a nominal diameter and wall thickness (defined by the pipe schedule). This article provides characteristics for NPS piping in metric units.

Nominal Pipe Size (NPS) is a defined set of standard pipe sizes commonly used for process piping. NPS piping is defined in terms of a nominal diameter and wall thickness (defined by the pipe schedule). This article provides characteristics for NPS piping in Imperial units.

The calculation of a horizontal vessels wetted area and volume is required for engineering tasks such fire studies and the determination of level alarms and control set points. However the calculation of these parameters is complicated by the geometry of the vessel, particularly the heads. This article details formulae for calculating the wetted area and volume of these vessels for various types of curved ends including: hemispherical, torispherical, semi-ellipsoidal and bumped ends.

When a fluid moves from a tank or vessel into a pipe system or vice versa there are pressure losses. This article provides K-values for pipe entrances and exits of various geometries. These K-values may be used to determine the pressure loss from a fluid flowing through these entrances and exits.