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 is “stripped” of sulfur compounds by the addition of hot steam).

Over that time period, the sightglass (level gauge LG-11) has shown the liquid level inside vessel C-406 drifting between 2 feet 5 inches and 2 feet 8 inches:

Process High Level Alarm Example

Process Control High Level Alarm Fault Analysis

Click on the Image to Zoom

Identify the likelihood of each specified fault in this process.

Consider each fault one at a time (i.e. no coincidental faults), determining whether or not each fault could independently account for all measurements and symptoms in this process.

Level Transmitter Fault Analysis

Answer :

The below table shows the possible and  Impossible cases for the process high level.

Process Control High Level

Share Your Answers via Comments

Articles You May Like :

Failsafe Wiring Practices

Difference between PLC & DCS

Process Control Loops

Shutdown Philosophy

Fire & Gas system Alarm

Don't Miss Our Updates
Be the first to get exclusive content straight to your email.
We promise not to spam you. You can unsubscribe at any time.
Invalid email address

Leave a Comment