Structural Changes To Xylem's Underdrain Offering Eases Installation And Increases Resistance To Uplift
Ron Port, Vice President of Xylem Inc.’s Treatment Business Unit and Xylem China, discusses the benefits of Xylem’s new XA Underdrain product.
The following is an excerpt from a Q&A with Water Online Radio. Click on the Radio Player above to hear the full interview.
Water Online Radio: What did Xylem unveil yesterday at ACE 13?
Ron: We unveiled our first new under drain product in probably about fifteen years. It's a type XA underdrain, which has some added features and benefits, and actually, the best underdrain product on the market for filter systems.
Water Online Radio: Underdrain, that's not a term that I've heard of before. Help this lowly radio guy understand what that actually is.
Ron: A basic gravity filter has filter media on top, and underneath the media is the underdrain system, which is used to support the media and used to properly distribute air and water during the cleaning cycle.
The main function of the underdrain is the distribution of air and water during the cleaning cycle, to make sure the filter gets cleaned. Keep in mind that in a city drinking water plant, filters can be very large, 10 by 30 feet, so 300 square feet and above.
Water Online Radio: What's different about this XA underdrain? Why should I get excited about it?
Ron: That's a good question. The key thing that's different about this underdrain is the hold-down part of the underdrain that we've added. On the bottom, there is a grout log that embeds into the grout, because you cement the underdrain into the filter itself, to create a solid floor.
The grout log underneath has some holes in the bottom, which allows it to anchor into the underdrain which increases its resistance to uplift force and failure of the underdrain system, which is one of the bigger problems that a city may have. If there is too much pressure in the backwash, it can cause a failure. This helps overcome that.
Water Online Radio: What are some of the other problems and issues that this underdrain addresses?
Ron: Back in 1994, we came out with our type S underdrain. That was the market leader as it related to distribution of air and water and getting the best distribution in the filter. When you look at underdrain products, we've pretty much peaked that distribution curve, and you really can't do much better to improve distribution.
Water Online Radio: Physics is a limitation, right?
Ron: Exactly. Now we're in a situation where we're looking at the other problems the customer may have had and try and overcome those problems. Not only the end user customer being a municipality, but also the general contractor who installs it.
We went for a product that has an easier installation procedure, and in addition, has the higher resistance to uplift force, which gives more protection to the end user municipality.
Those are a couple of the key decision points that they have now, whenever they're looking at it, in addition to the fact that it still maintains the superior distribution that we have with our underdrain product…
Click on the Radio Player above to hear the full interview.