Swimming Pool Filter Explosion Causes Blindness and Brain Damage

This case involves a swimming pool filter exploding and injuring a woman. The plaintiff was preparing the swimming pool for her family’s first summer living in a new house. The woman had a pool at her previous residence and was knowledgeable about opening pools for the summer, though she was unfamiliar with the two- part water filtration system at her new home. She took apart the filter once to clean each piece, and then reassembled it according to the user manual. After turning on the filter, the plaintiff stood by to monitor the air pressure gauge. The filter exploded and the top flew off, hitting the woman in the face, completely blinding her and leaving her with severe brain damage.

Question(s) For Expert Witness

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

Expert Witness Response

As an engineer, I have had extensive experience working with the pool hydraulic system and have studied the pneumatic separation (or “explosion”) described. The two-part pool filter system has a bottom and top piece fitted together with a belt-like band. Over the last two decades, there have been many reports of the tops of these pool filters suddenly separating and being blasted off at extremely high speeds. These incidents, in which the tops are known to fly up to 100 feet in the air, are mostly caused by a buildup in air pressure within the filter. Pool filter systems should be cleaned about twice a month by removing the cardboard filters, hosing them down, and fastening them back in. After being cleaned, the tank has to be turned on and pressurized again, which is typically when the “explosions” happen without warning. The separation also tends to occur if the top of the filter does not perfectly sit on the bottom part when the band is applied and secured. The person cleaning the filter may believe that the seal is secure, when actually, they have just set up a time bomb. Though feasible design alternatives which eliminate these explosions exist and have been available for decades, most manufacturers still refuse to recall the dangerous designs. The safer models require more time and effort to clean the filters and might even necessitate special tools or knowledge to clean a pool.