Magnetic Level Gauge Float Design
Magnetic level gauge work on the principle of communicating vessels, therefore the level in the measuring chamber will be the same as the level in the vessel. The measuring chamber…
SWAS Analyzers Questions and Answers
Steam and water analysis system (SWAS) is a system dedicated to the analysis of steam or water. In power stations, it is usually used to analyze boiler steam and water…
DeMorgan’s Theorems using Ladder Diagram
DeMorgan theorem is used in digital electronics. Explain the De Morgan theorem using PLC ladder language. DeMorgan’s Theorems are two additional simplification techniques that can be used to simplify Boolean…
Instrumentation documents
Different types of instrumentation documents are loop diagrams, functional diagrams, piping and instrumentation diagrams.
When to use a Diaphragm Seal?
Process measurement sensors are not indestructible. Not even the most rugged device is fully immune to the chemical nature of process media or the kinetic impact associated with fluid composition…
Process Control Loop Testing
A very useful technique for testing process control loop response is to subject it to a “step-change” in controller output. In other words, the process is perturbed (the highly technical…
Identify Level Control Loop Tuning Problems
A level control loop is supposed to maintain a constant level of liquid at the bottom of the stripping tower where considerable amount of vibration exists, but it seems to have…
PLC Permissive for Motor Control
A engineer needs to write a PLC program to control a water pump driven by an electric motor. This water pump will be manually started and stopped by pushbutton switches,…
Process Control High Level Alarm Fault Analysis
An operator reports a high level alarm (LAH-12) displayed at the control room for the last 13 hours of operation, in this sour water stripping tower unit (where sulfide-laden water…
Compressor Emergency Shutdown Root Cause Analysis
The compressor emergency shutdown system (ESD) has tripped the natural gas compressor off-line three times in the past 24 hours. Each time the operator goes to reset the compressor interlock,…
