Engineering & Simulation Consultants


There is a recurring number that despite magnificent developments in technical safety doesn’t seem to go away. That number is 80, and it relates to the percentage of incidents that in some way has been contributed to by a human. It is a recurring average across industry and in different settings. Looking on the bright side, it means that there is huge scope to make a significant improvement. So how can we reduce the rate at which people contribute to incidents? The first step is to recognise that human failure is not random, but systematically linked to the tasks that people perform, the equipment they use, and the characteristics of the work environment. By understanding these elements it is possible to reduce the potential for errors to occur in the first instance, or at least to pre-empt them so that when they do occur, they can be safeguarded against.

This article, published by The Chemical Engineer, provides an overview of human failure, the factors that contribute to it and the process by which the risks can be reduced.


When designing a pipeline or a piping network for process plants, care should be taken to ensure the pipe and equipment are sized correctly. Specifying an oversized pump whilst under sizing the pipe diameter may increase pump purchase and operating costs. In contrast, specifying an undersized pump coupled with an oversized pipe diameter will reduce pump related costs, yet increase the purchase and installation costs of pipes. The correct combination of pump and pipe diameter need to be specified to present the most economical piping system.

This article aims to demonstrate a calculation method to determine with reasonable accuracy the most economical pipe diameter, taking into consideration the installation cost of pipe and pump operating cost throughout its design life. This article is complimentary can be downloaded by clicking the icon on the left and follow the instructions accordingly.


As one of the established engineering design firms, we have delivered engineering design services in plant engineering to clients in the chemical & petrochemical industry, manufacturing, mining & mineral processing, oil & gas, pharmaceutical, renewable energy, semiconductor and water & wastewater industries. ​The papers below, compiled by our process design consultants, can assist engineers on a few of the crucial tasks associated with plant design.


A pressure relief valve protects process equipment from the hazards of high (or low) pressure in a process. It operates by opening at a designated pressure and ejecting mass from the process equipment. The ejected mass contains energy - the removal of the energy reduces the process pressure. Sizing the pressure relief valve incorrectly may lead to undesirable results such as ejecting insufficient amount of mass as a function of time. 

This article, published by American Institute of Engineers (AIChE), provides an introduction to sizing a pressure relief valve. The article is provided for educational purpose only and readers are recommended to consult experienced professional engineers to conduct this task.

Economic Pipe Diameter - Jimmy Lea P/L
Reduce Human Failure - Jimmy Lea P/L
Pressure Relief Valve - Jimmy Lea P/L