Technical & Practical
Would You Use a Safety PLC for Process Control?
With today’s state-of-the-art digital technology, the sky seems to be the limit for doing everything with one system platform. However, with the exception of a few very specific applications, using a safety PLC (programmable logic controller) for process control is…
Steam Tracer Lines and Traps
Steam tracer lines are designed to maintain the fluid in a primary pipe at a designated uniform temperature. In most cases, these tracer lines are used outdoors, which makes ambient weather conditions a critical consideration. The primary purpose of steam…
Doing an Energy Audit
Today’s high costs of energy make an energy audit evaluation of process facilities a must. Most plants were designed and built when energy costs were low by today’s standards. This makes facilities that have not been reviewed for energy efficiency…
The ‘BIST’ In Electronic Valve Actuators
For valves operating in hazardous environments, certification testing is critical to ensure the reliability and safety of the equipment. But this testing process has historically required facilities to shut down and sacrifice valuable production hours to check each valve. Built-in…
Positive Displacement Pumps
Pumps are essential equipment in the chemical process industries (CPI). Given the imperatives to reduce production costs and maximize energy efficiency, pump selection is crucial. Knowledge of pumping basics, along with the fluid characteristics for a particular application can help…
Variable Frequency Drives: An Algorithm for Selecting VFDs for Centrifugal Pumps
This article describes an algorithm that end users can use to develop a program on a personal computer to assess the technical and economic feasibility of installing a variable frequency drive (VFD) on centrifugal pumps. This simple algorithm serves a…
Kettle Troubleshooting
A survey of tower failures [ 1 ] ranks kettle reboilers as the most troublesome reboiler type in the chemical process industries (CPI). Excessive pressure drop in kettle reboiler circuits is the prominent kettle malfunction, causing liquid to back up…
Low-Pressure Measurement
Because of the behavior of materials under vacuum, including lowered boiling points, low-pressure operations are useful tools in chemical processing, as well as in research and development and manufacturing. Areas where a vacuum system is necessary or useful include the…
A ‘Sound’ Solution to Material Flow Problems
Particulate buildup and other material flow problems are common hurdles wherever dry materials find application in the chemical process industries (CPI). Since manual intervention is costly in terms of downtime, and can be quite hazardous for the personnel involved, dedicated…
Updating the Rules For Pipe Sizing
Pipe sizing calculations include certain values that are time dependent, such as costs. While some costs rise, others decrease over time. It is the designers task to ensure that the total cost is minimized. For fluid flow calculations, heuristic criteria…