WIND EVANS, FLEXCON INDUSTRIES INC.
Director of marketing and business development discusses the use of well tanks and their future.
By Mike Price
Flexcon Industries Inc. regularly gives plant tours at its factory in Randolph, Massachusetts. The pressurized diaphragm expansion tank manufacturer is proud to show the evolution of the well tank. Going from a galvanized tank with no diaphragm or bladder to a captive air tank (true separation between water and air) in the 1960s was groundbreaking.
Which well tank a water well contractor uses often comes down to relationships and personal experience with the tank, says Wind Evans, director of marketing and business development for Flexcon for more than 25 years.
With Evans’ industry experience, Water Well Journal thought it was a good time to catch up with him to learn more about the state of the well tank market.
Water Well Journal: How do you go about educating customers on the basics of a well tank?
Wind Evans: The primary goal for a tank manufacturer is not keeping water in the tank, it’s keeping air in the tank. We work off a physics principle called Boyle’s law. Essentially, the law is simple: you can’t compress water, but you can compress air. When you have an air charge in a tank, as you fill the tank up, you basically compress that air and then that air acts kind of like a spring and it pushes the diaphragm when the pump is not running, and it empties the tank.
The No. 1 thing to think of in a well tank is to not really think of it as a storage device but to think of it as part of the control system to operate the pump because it works in conjunction with the pressure switch.
Conventional systems use a pressure switch and tank. Constant pressure systems add a wrinkle to everything with variable frequency drive pumps. The whole premise is that with a single-phase motor when the pump starts, it generates an incredible amount of heat in the motor. The whole idea of the tank is to allow the pump to run long enough so that the motor can cool off. With all that heat generated, the way the motor cools itself is with all the windings in the motor. Generating all this heat—copper is a good conductor of heat—heat will transmit throughout all that copper winding and it’ll cool the motor off. If you didn’t have that and continually started that motor and it heats up, eventually it’ll burn one of those wires and then the motor is shot. You can talk to pump guys all day long and they can tell you about it.
We talk to customers and find the key to having a good system is the design of the system. You take your pump, which is chosen based on the amount of water, depth of water, etc. and whatever demand is present, say irrigation vs. residential. You’ll size your pump and want to size your tank to have enough drawdown (amount of water you store in the tank based on the pressure switch).
WWJ: How does one ensure the motor won’t burn out?
Wind: Typically, on a fractional hp motor like ½ hp, 10 gallons a minute pump or ¾ hp, 8 gallons a minute pump, you want to have one minute of runtime to cool the motor. If it’s an 8 gallons a minute pump, you want 8 gallons of storage; if it’s a 10 gpm pump, 10 gallons of storage. With the design of the system, you would pick the tank that would give you the correct amount of drawdown so that the motor is not going to burn out. In essence, designing the system is basically trying to make that system last as long as possible.
WWJ: What has been your experience with diaphragm tanks by customers?
Wind: Guys will tell you the old stuff lasted for 15, 20 years, and the new stuff doesn’t last as long. But I think a lot of it has to do with what our dads did or what the market is asking for. If the water well contractor is working for a contractor building a house and all the builder cares about is it makes it through the one-year warranty of the house, he is going to want the cheapest system possible. The builder could cut corners, and an easy corner to cut is putting a little bit smaller tank in there.
When we talk with customers, we basically tell them what to look for in a tank. And one of the things we concluded is diaphragm tanks seem to last longer than a lot of other tanks.
The main premise is the way a diaphragm tank is constructed, a diaphragm has a predictable motion. By being able to predict the motion of the diaphragm, you can construct the diaphragm so it will last a long time and not wear out vs. the bag option. If you had a bag in the tank, it can take different shapes and there is surface area. The more surface area you’re trying to keep air from permeating through, the greater the possibility of you losing the air in the tank.
It goes back to the principle we’re trying to keep air in the tank. Diaphragms have the smallest surface area, and we use butyl rubber to make them. That’s the best material we’ve found to keep air from leaking out of the tank.
WWJ: What else are determining factors in sizing the right well tank?
Wind: We look at things like where the tank is going to go; is it going to go in an area where you’ve got a hostile environment? If so, you’d probably recommend a composite or fiberglass tank there because they tend not to rust.
Sometimes the conditions are: What do you do if you have no place to put the tank except outside and it’s a cold climate? You’ve got to figure out a way to protect it. A lot of times they’ll put it—if you don’t have a basement—say it’s a slab house or a mobile home, in a crawl space. In some markets they use an insulated box with some form of heat.
We recently had a group of guys from Maine here, and what they did under the mobile home is build an insulated box for the tank and put an incandescent light bulb in there to generate just enough heat to prevent the pipe from freezing. The downside on that is if the bulb blows, your pipe is going to freeze.
WWJ: When it comes to contact tanks for water treatment, what are you telling pump and tank installers?
Wind: It’s going to be a total volume tank and it kind of depends on what kind of water treatment they’re doing. Nine times out of 10, they’re going to use one of the tanks for treating the water chemically like injecting chlorine or say injecting sodium hypochlorite to raise the pH of the water. The tank is primarily used for mixing, so you want to retain the water in the tank as long as possible and then allow the chemical to treat the water. There is usually a secondary process after that. That’s pretty much dependent on what they’re treating.
If you’re trying to kill bacteria, there is a specific formula in it for contact time; generally, they want 20 minutes of contact time. The EPA has a technical guideline on treatment for killing viruses and bacteria which incorporates chlorine injection vs. ultraviolet treatment. Part of the guideline is you have to have a baffle retention tank to allow the water to stay in the tank longer, so we actually designed a baffle retention tank to keep the water in the tank much longer so the chemicals can do their job.
Depending on what market, every health department has a different regulation on what they want, so it’s a hometown rule in terms of what is required. A lot of the water treatment, truth be told, is aesthetic. It’s getting iron out of the water that’s staining clothes, or if you’re irrigating, it’s staining the sidewalk.
WWJ: How have you seen pump and tank installers moving toward adding water treatment to their services?
Wind: Some guys are just putting pumps and tanks in, but a good number are doing water treatment now too. Based on what they can handle, they want to do as much of that as they can when it comes to the source of water going into the house. I think a lot of it then depends on how much aftermarket stuff they want to do with the homeowner.
I can’t speak to water well drillers, but the pump and tank guys want to keep in touch with homeowners and focus on service. Water treatment contractors are all about service. If you put water treatment in and you’re not servicing it, eventually it’s going to fail.
We had a group in here recently and I told them if you don’t want to have a warranty, check the air pressure and adjust the air pressure on a captive air tank once a year. I can virtually guarantee you’re not going to have a warranty due to the pressure loss. It’ll last a long time if it’s sized correctly. Unless there is a manufacturer defect in the tank, the tanks don’t lose pressure that quickly that you wouldn’t catch in a year. And yet a lot of guys don’t do it; they’re too busy.
WWJ: For hydronic and geothermal heating and cooling applications, your company debuted the first composite buffer tank at the beginning of this year. How has it been received by the market?
Wind: It stalled until the geothermal tax credits came back (laughs), but it’s picking up again. Basically, what a buffer tank does is, it’s like a battery in that it stores hot water. What it’s designed to do is it helps the heat pump run longer. The longer a heat pump runs, the more efficient it is. Every time a heat pump starts and stops, it takes a lot of energy and shortens the life of the heat pump because it wants to start and run for long periods of time. The buffer tank adds a little additional volume to the system without affecting the efficiency of the heat pump.
Our buffer tanks are kind of unique because they’re also rated for domestic hot water so you can use it for your drinking water too. A lot of times what will happen on combination wall-hung boilers that can be used for both heating your house as well as heating your domestic hot water is a lot of them only supply between 2 and 4 gpm. If you’ve got a lot of hot water usage in your house, it’s nice to have that extra buffer of additional water on demand. We partnered with a company that had a new foaming process that allows us to really get a high R-value (rating of insulation’s effectiveness) insulated tank that’s composite, so it’ll never rust and takes advantage of our composite technology.
WWJ: What does the future look like for well tanks? Are there any new technological advancements on the horizon?
Wind: My sense is contractors are going to have to be a little bit more efficient because they may end up covering greater territories. The average age of an installer is getting up there. Twenty-five years ago, I was a kid. I’m 60 now.
I think technology is going to take a bigger hold in the sense the next generation of customers coming in are way more tech savvy than our present customer base in the sense the next generation of customers coming in are way more tech savvy than our present customer base in the sense I think they do more with their mobile devices than we currently use. We’re taking a long, hard look at that and seeing if there are ways we can incorporate some of that into our business, like a mobile sizing app. It wouldn’t surprise me that in the future a lot of the selling of products will probably be done on a device as opposed to calling or having a salesman stop by. It’s kind of the Amazon effect.
In terms of technological advancements, it’s always amazing to me how good a pressure switch is on the marketplace and how difficult it’s been to replace it with something else. For the most part, it’s a pretty reliable device. If you look at how many switches vs. constant pressure systems are sold, it’ll open your eyes. My sense is if you can find something better than a pressure switch for the money, you’ve got a winner there. I look at it every day, and I’m like gosh, can I find something better than that? I have been searching for several years now and I haven’t found anything.
However, we didn’t turn a blind eye to the pump manufacturers making constant pressure systems in 2000. We took a close, hard look to see if we could come up with a tank to complement these products and I think we did a good job with Flow-Thru tanks. We’ve been able to adjust by making a bigger tank now for that market. We keep a close eye on what pump guys do because we work hand in hand with them.
WWJ: Lastly, how has business been for expansion and contact well tanks?
Wind: We’ve had a very good year so far. I always talk about this with caution, but I’m getting a vibe from most pump and tank installers that they’re staying pretty busy.
Business has been good the last few years. We’ve seen steady growth, and this has been a strong year. 2005 and 2006 were really good years with the housing market booming.I think some of that was attributed to the replacement cycle with tanks not sized correctly and they eventually fail. Business is pretty good right now and it might be a replacement cycle based on good business 10 years ago before our recession. We’re cautiously optimistic.
Mike Price is the senior editor of Water Well Journal. In addition to his WWJ responsibilities, Price contributes to the Association’s scientific publications. He can be reached at firstname.lastname@example.org.