June, 2003

200301JunAll DayInterlocked for a reasonProcess Safety Beacon | Every Protective Device has a Purpose. Don't Defeat itLessons:Asset integrityLanguage:EN Origin: CCPS Document Type:BulletinTopics:Functional Safety


Here’s What Happened:

This heater was severely damaged during start up as a result of a fire box explosion. The operator had some difficulty with the instrumentation and decided to complete the start up by bypassing the interlocks. This allowed the fuel line to be commissioned with the pilots out. The main gas valve was opened and gas filled the heater. Then … K A B O O M, the heater exploded destroying the casing and damaging several tubes. Fortunately, no one was injured.

Why Did this Happen?

The operator thought that he could speed up the job by shortcutting some of the “unnecessary” things in the start up procedure. He misjudged the importance of the interlocks. He thought they could be by-passed … just this one time, but he was wrong. They were important … this time and every time!

© AIChE | Messages for Manufacturing Personnel


CCPSCenter for Chemical Process Safety