Hydraulic Engineers Evaluate Fatal Injuries Caused by Filter Unit Explosion

Case Overview

This case involves a pool filter that catastrophically malfunctioned, causing fatal injuries to an employee at a public swimming pool in Hawaii. On the date of the incident in question, the employee had been tasked with replacing a filter unit in the pool’s water filtration system. In order to begin the replacement process, the employee depressurized the filtration system and loosened a metal band that secured the filter cartridge while the system was in use. The employee then replaced the cartridge, tightened the band, and re-activated the system. He noticed that the cartridge was leaking under the pressure, and went to apply additional tension to the band. Suddenly, the top of the filter exploded, driving metal fragments into the employee’s face and skull. He was taken to the hospital, where he died shortly after arrival.

Questions to the Mechanical Engineering expert and their responses

Please discuss your background in design pool filter systems.

As president of my own consulting firm, I have tested filters like this numerous times. I have extensive experience in designing, engineering, and testing pool filters. As the director of engineering for a major swimming pool manufacturer, I engineered and pressure tested more than 300,000 filters over 10 years.

What could have led to the explosion of the two-part pool filter?

I have seen the accident described in this case hundreds of times; it is referred to as pneumatic separation. I have seen this 'explosion' happen hundreds of times, and am familiar with all the causes and preventative measures that could be taken. Normally, filters like this would have warnings on the package or the filter itself against tightening while the filter is on, which may have advised the employee against the dangerous actions he took if it was indeed present.

About the expert

This expert is an engineer who specializes in pool design and filtration. His world renown research, expertise, and innovations during more than 40 years as a licensed professional engineer have earned him the industry's highest honors, including his election as Life Fellow in the American Society of Mechanical Engineers (ASME). He is very well published in the field of aquatic device safety and engineering, and has served as a principal engineer for multiple pool filtration companies in the past. Currently, this expert is the President of his own design and forensic engineering firm that deals with swimming pools, heating, and filters.

E-009275

Specialties:

Mechanical Engineering