This is What Makes Above-Ground Backflow Enclosures So Safe

When an industry expert starts talking about backflow enclosures, we tend to listen. During an interview about two completely different topics, Sean Cleary of The International Association of Plumbing & Mechanical Officials, was asked for his thoughts on above-ground backflow enclosures. He had a lot to say.

Cleary is the vice president of the International Association of Plumbing and Mechanical Officials (IAPMO) and the Backflow Prevention Institute (BPI). He’s a licensed master plumber who’s worked in all phases of the cross-connection, plumbing, and mechanical industries. He’s been in the business for over 40 years.

In part one of our discussion, Cleary offers his opinion on a number of backflow enclosure-related topics. Here’s a breakdown of the Q & A.

Backflow Enclosure Questions Answered:

Did You Ever Install a Backflow Preventer in a Vault?

“The company I used to work for, we installed RPs in pits and vaults because that’s where the facility wanted them. In a lot of cases, the water companies gave a variance to allow them to be installed in pits and vaults. And they don’t belong in pits and vaults.”

Why Should Backflow Preventers Be Installed Outside?

“A valve of any size, once we get to 4 and 6, 8, 10-inch backflow preventers, reduced-principle assemblies installing them in a building, that does not have the draining capacity is a problem. And it’s a huge liability to the installer. It’s a huge liability to the tester. If I have a valve that can dump 7, 8, 900 gallons a minute in failure and I have a drainage system in the building that can evacuate 400 gallons a minue—this math doesn’t work.”

Why Are Outdoor, Above-Ground Backflow Enclosures Better?

“Installing them outside, in a backflow enclosure will prevent the flooding of the building and I have seen buildings flood 3 or 4 times, myself. Early in my career, I flooded a department store when I was testing a backflow preventer and the relief valve got stuck. There was no drainage in that area of the store and it did quite a bit of damage.”

Cleary says if the valve would have been installed in a backflow enclosure located outside of the building, it wouldn’t have been an issue.

You can find out more about backflow prevention assemblies and where they should be installed by looking through our guide “Trends in Backflow Preventer Installation.” It’s a great resource for anyone responsible for commercial water supply and infrastructure.