In Part 1 of our interview with Sean Cleary, he talked about learning the hard way why backflow preventers should be placed in an outdoor, above-ground backflow enclosure. He’s the vice president of the International Association of Plumbing and Mechanical Officials (IAPMO) and the Backflow Prevention Institute (BPI). He shared some of his thoughts with us on backflow enclosures.
In this post, he’s answering a few questions about the cost-effectiveness of above-ground, outdoor backflow enclosures.
Why Should Backflow Preventers Be Outside?
“I’ve seen what a valve can do inside. I’ve seen the flooding that could happen. I’ve seen enough instances of that occurring to understand that large valves definitely do not belong where there’s no drainage capacity for them. I’ve seen fire system backflows installed in penthouses, on roofs of hotels, so they would have the roof to dump out onto because there is no way the building drain could handle the amount of water. If you can install the valve somewhere where it can naturally drain outside of the building—that does make perfect sense.”
Are People Beginning To Move Valves To Outdoor Backflow Enclosures?
“You do see with the education and training that is going on, people are learning their lessons. I mean, more valves are going in backflow enclosures, more valves are going above ground, which, to be honest, is where they belong.”
Are Outdoor, Above-Ground Backflow Enclosures More Cost-Effective?
“For me to test a backflow preventer in a meter vault, as a confined space, it’s going to (increase) the cost of that test. I’m going to need three people, I’m going to need a lift, I’m going to need a harness, I’m going to need to monitor the conditions inside the vault. When you factor all of those things in, on a yearly basis, it makes sense to move it outside and put it in an enclosure.”
Is Testing and Maintenance Easier With a Backflow Enclosure?
“It definitely makes it easier than a pit or a vault. When you’re in a pit or a vault, you have all of those issues related to confined spaces. And in the long run, if you balance the costs, it simply makes more sense to put the valve where it’s accessible because it is a mechanical device that is going to need maintenance. The International Plumbing Code says the valve has to be accessible.”
Cleary says you always have to consider drainage capacity, testing and maintenance. For those reasons alone, your backflow preventer is typically better off outside.
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.