Simplicity Under Pressure—The Valve That Delivers

A mechanical solution that saves water, saves energy, and saves pump motors

cycle-stop-valve

Credit: HOOKS, TX

The warning saying “if it sounds too good to be true, it probably is,” comes to mind when you are promised overnight weight loss and gimmicks that make you rich. But sometimes, an invention comes along that delivers what it promises so well that it really does seem “too good to be true.”

A Counterintuitive Success Story
More than two decades ago, an enterprising young man with a pump and drilling background had a brilliant idea. He wanted to develop a means to control water pressure that was simple, reliable, and not dependent on a power source. Today, no longer a young man, Cary Austin, the inventor and owner of Cycle Stop Valves (CSV) headquartered in Lubbock, TX, says his invention works so well and is so reliable that the products “will probably still be working as good as the day they were installed after I’m long gone!”

Credit: CYCLE STOP VALVES Several cycle stop valves in use

Credit: CYCLE STOP VALVES
Several cycle stop valves in use

While CSVs are in place around the world, Austin says there are still disbelievers who can’t fathom “the simplicity of a mechanical valve that can deliver constant water pressure with equal efficiency from small flows like a single garden hose to as much flow as the pump can deliver.”

“It’s counterintuitive to what you think will work,” explains Austin, describing how the valve can efficiently manage fluctuations in the downstream water pressure and not burn up the system’s pumps or motors.

“What happens is that the CSV opens and closes like a ball valve—it uses a spring to push it open and then a diaphragm will push it closed. The beauty of this is that the customer sets the valve at the required outgoing pressure, and that’s where it stays. So, let’s say they want all the outgoing water at 50 pounds per square inch gauge, the valve responds to the amount of water being used—if it is more or less—by opening or closing in response to downstream pressure. This simple mechanism ensures that all outgoing water is exactly at 50 pounds per square inch gauge.”

Austin says the size of the pressure tank is irrelevant. It doesn’t matter if the tank holds 1 gallon or 1 million gallons. Water goes from the pump and CSV right past the tank, directly to distribution, matching the exact flow rate being used.

Meeting Demand—One Shower, Or the Whole Town
During your stay in a large hotel you may have experienced the “morning shower phenomenon” when water pressure drops due to the demand of hundreds of people turning on the taps at the same time, something that would be a non-issue at three in the morning when most are asleep. Austin takes the illustration to a larger scale to explain how CSV maintains a constant pressure, regardless of demand, and wherever water is being used—a public utility, an irrigation system, and even a garden hose.

At 7 a.m., the demand will be different from 3 p.m. and midnight. Imagine a large pressure tank or a water tower. The pump runs at full flow until the tank is full, then the pump shuts off. Demand drains the tank as needed, then the pump is restarted and the tank is filled again. This (cycling) is repeated over and over. But the CSV, which is set to 50 psi by an adjustment bolt that sets the spring tension inside the housing, will always deliver exactly that level of outgoing water pressure, regardless of changes in demand. And, the utility will enjoy a constant 50 psi, which can also maintain a level of 115 feet in a water tower, rather than continuously dropping and then refilling. As more or fewer taps are open, the valve responds by opening and closing to deliver constant pressure.

But, explains Austin, the skeptics still argue that restricting the pump with a valve of this design can cause the pump/motor to burn out, despite the evidence from engineering research that has proven the exact opposite happens.

“The CSV has no control over motor speed because it just opens or closes in response to deliver the correct water and match the water amount being used. Many people think choking a pump back with a valve makes the amps go up and this makes the pump work harder, and that slowing the pump would make it work easier,” says Austin.

“But in fact, we’ve done years of testing and a good pump engineer will know that the very opposite is true. When you restrict the flow from a centrifugal type pump, you reduce the draw on amps, and this makes its work easier, but reducing the actual speed of the motor can be very hard on it.”

And anyone who has wrestled with a hand mixer in the kitchen on heavy dough knows that distinctive, electrical smell of warning when the motor is fighting a tough bread; because the dough is slowing down the motor, you have to set the motor on a higher speed. Austin says this is what most people think happens when you restrict a pump with a valve, but is just the opposite of what happens. Restricting a pump with a valve is more like putting your hand over the inlet of a vacuum cleaner or the discharge of a blow dryer. You will actually hear it speed up, as there is almost no load on the motor when flow is restricted.

Eliminating the Wave of Destruction
While delivering constant pressure is the CSV’s primary job, its design offers users other benefits as well. The consistent delivery from the opening and closing mechanical valve eliminates the transient pressure waves, which Austin says are created when a pump starts and stops and the jolting energy causes water hammer. “When things are in motion they want to stay in motion,” he explains.

“These transient pressure waves travel from 3,000–8,000 feet per second, and a pressure tank tries to catch these waves after they happen; but, it’s too little too late and is something like trying to catch a bullet with your teeth. When these waves encounter tees or a 90 degree turn they don’t like it, and this can cause joints to break.”

Austin says he is familiar with utility workers whose entire job description is fixing pipe breaks from water hammer. With the CSV, he says, “The check valve is open only the width of a piece of paper when the pump shuts off, and there is no surging, so there is no water hammer ‘to catch.'”

Converting the Skeptics
While some are reluctant to embrace the concept of the CSV, one engineer has become a convert to the principle and is enthusiastic about the variety of potential applications.

Kiron Brown, P.E. with A.L. Franks Engineering, Texarkana, AR, a professional engineering service with significant expertise in public works projects, says the CSV “could be used anytime you want to maintain a certain pressure of a liquid.” He explains that “Every pump has a head curve, and this matches the amount of water that flows against a known elevation. If a pump turns on and it has to pump [water] up to a 300-foot tower, it has to match what it is supposed to do because they don’t like to operate off that curve. Each pump has a set of conditions for it to be efficient.”

“So with the CSV, when they’re wide open and flowing, and the pump is working the way it is designed, the pressure starts to go up.” When it reaches the set pressure of the CSV the valve starts to close and creates an artificial head, which Brown says intuitively seems like it would be hard on the pump, as it would not be operating in its ideal condition.

Brown adds that “You design for a certain backpressure that the pump is going to be in most of the time, and when you add the CSV you would think, ‘oh, this is going to burn the motor up,’ as it appears like the valve is wanting it to pump less water than would actually flow. But, this doesn’t happen because the valve is controlled and designed so that it is always flowing, and it is never less than 5 gallons per minute—this allows those pumps to cool and keep working.”

Plus, Brown says that “there’s no electrical component; it’s all set on a pressure model and it will close off to not let a lot of water in, and if a lot of water is released, it opens up, but is consistent in pressure.”

In one instance, Brown said the CSV was the most economical solution to a water tower that was taken out of service. “I had people tell me it would burn up [the pump] and I actually said the same thing, but after we installed it, I assure you we ran the city water for three months on that valve, the pumps, and the ground tank with no problem—it operated just flawlessly (without a water tower in service).”

No Voltage, Longer Life
By using the CSV, the city was able to keep its water supply and not have to resort to a popoff valve, losing money and a precious water resource. Brown says if you use a variable-frequency drive (VFD) “they change the frequency of the power to the motor to make it run, which allows it to run slower or faster, but it is dependent on electrical supply.”

And Austin adds that by eliminating the inherent problems that are typical of a VFD, the CSV actually increases the life of the pump and every component in the system.

“With motors running on pure across-the-line sinusoidal voltage, the CSV eliminates harmonics, voltage spikes, bearing currents, and many other problems associated with VFDs. Moreover, the constant pressure from CSVs eliminates line breaks and is saving millions of gallons of precious fresh water every day.”

With so many cities suffering from aging infrastructure, saving water from broken lines is crucial. Austin says that some municipal systems are losing as much as 50% of water from leaks and breaks that he asserts are in large part the result of pumps cycling and causing years of constant water hammer. But fixing the leaks “without fixing the cycling—the source of the problem—is literally like throwing money down the drain.”

Brown also envisions being able to use the CSV on projects such as irrigation where a system that provides water to another system is located “a pretty good distance away.” In this instance he describes how pumps can cause a lot of vibration in the long-distance lines but if the CSV were in use, “the pumps wouldn’t kick on and off, hammering with full flow, and water pressure and flow would match usage.”

Wells—The Country Life But Even Better
In the far western Canadian province of British Columbia, Lloyd Ingram, CEO of Ingram Well Inc., is also an enthusiast of the Cycle Stop Valve capabilities. He says he discovered the product at a National Groundwater show in 1993 and a year later he had a suitable application to try it out. After tracking down the company, he asked Austin to create a CSV for a specific need.

“We retrofitted the whole pressure tank, and on the first time of filling, we used a garden hose—we were nervous the thing was going to blow up, but it worked perfectly. We go back to the site every three years and all we did is put a new controller on and the same valve is working just fine.”

Since then Ingram has used the CSV as a mainstay of his business serving customers within a 500–800 mile radius from the home office.

Ingram says that their locality, Quennel, BC, has 8,000 residents who are on city water, but outside of that area, “there are about 25,000 people who are not on the main. They all have wells, and they almost all have a Cycle Stop Valve.”

He said the residential installations started with one person who put one in to maintain the erratic pressure from their well, and his neighbors were so impressed it started a chain reaction.

“Now, when we quote a residential well job, the customer doesn’t even know about it, we just install them as part of our subdivision work.”

Ingram says he’s put in thousands of CSVs and he still hears from people who say “how can that valve do that?”

“‘It’s too simple of a valve,’ is what people think, because a lot of big pump companies are all pushing VFDs, saying they’re safer and better but they don’t do anything more than the CSV and in fact, they’re significantly more expensive and come with their own set of problems.”

Ingram explains when you need constant pressure and “you choke back on any centrifugal type pump, the amps will fall. It takes energy to move weight, and restricting flow from a 10-horsepower pump can make it drop to 5-horsepower amperage. A VFD is no better, and they don’t like voltage spikes, lightning, or power outages. The CSV is just a mechanical valve that delivers constant pressure without speeding up or slowing down the pump.”

Plus, Austin says that the reduced amperage and soft starts/stops of a CSV add more life to the pump/motor over other devices. Reducing pump start/stop cycles adds longevity to the pump motor, and “it will last longer. A CSV can make a pump start and stop at just 1 to 5 gallons per minute, depending on the size of the CSV.”

“We have actually tested this,” he says. The CSV basically de-rates the motor load enough and is pumping cool water, so there is less run and off-time needed for motor cooling.

More Contented Cows
While fluctuations in water pressure are normal for country living, Ingram says his customers are experiencing a constant city-type pressure from their wells. But rural life has other water needs, too.

“A friend of mine is an electrician and he has a lot of VFDs and swears by them. But I sold him one CSV and now he’s cut his VFD sales in half. And he’s used them in dairies where there’s been stray voltage in the water tanks the cows drink out of that is backfeeding from a VFD, and when he switched them to a CSV, he’s watched the cows go up to the tanks and drink out of them, without getting shocked as they did with the VFD.”

Ingram relates how his company was started in the ’60s by his father as a water well drilling and water pump company. He assumed ownership in the ’90s and has changed company direction keeping up with new technologies, but he says if a project requires water pressure he uses the CSV.

“We no longer drill, but provide kind of everything in terms of services with potable water. We work on dairies, some golf courses, gas refineries, and we’ve put CSV in all of those plus everything from high-rise buildings to trailer parks.”

But one massive problem solved by a CSV has turned into a five-year long loyal customer.

“About five years ago, a 40,000-acre cattle ranch with a long history—it was started in British Columbia about 1880—called me about their pumping station that was giving them problems. They had a VFD and they said ‘if you can get this thing running you can have all the work we have.’

“So we pulled that out and put in seven CSVs for the ranch. They have a huge demand for water what with five wells, a tank, ranch houses, irrigation, and then conveyance up to 6 kilometers to the windmill. It’s been a big success and it’s all still going strong.”

Conserving Water To Clean Clothes, Raise Cod, and Grow Corn
Austin is constantly finding new ways to demonstrate the durability and reliability of the CSV. “Back in 1992, we actually installed a 50-horsepower, 700-gallon-per-minute submersible pump, and ran it at 5 gallons per minute for six months to test for component wear, but when disassembled, it was virtually perfect. We put it back together and it’s been running ever since with no problems.”

Although it performs with any size pressure tank, it only requires a small tank, which reduces system investment. Some systems are supplying cities of 40,000 people using only an 80-gallon size bladder tank. And, because the water draw is steady and consistent rather than surging, this reduces the amount of debris and sediment in water that comes from sudden disturbances in a well.

While utilities are ideal beneficiaries of the valve, municipalities often want references from other water engineers, but as Austin says, “The pumps don’t know if they are supplying water to people, animals, vegetation, machinery, or whatever,” so it can be difficult to track down just where they are performing to get that coveted “seal of approval for municipal use.”

Nonetheless, he says providing constant water pressure is also crucial for so many industries, such as commercial laundries, car and truck washes, fish farms, or in any scenario that has a submersible, turbine, or centrifugal pump. When used in these applications that all require a variable flow, constant-pressure system, the user can also forget about line breaks and leaks, as they become pretty much a non-issue. The valve can react quickly to any system changes in demand while at the same time eliminating the negative and positive transient pressure waves by canceling them out with an equal and opposite pressure wave.

“This not only saves the system from breaks, but can conserve a huge amount of water and the energy required to move the lost water,” affirms Austin. Use of a CSV in irrigation for mist, drip, spray, or big gun sprinklers is perfect “for applying the precise amount of water required,” which also reduces runoff. But irrigation has its own quirks. The sudden demand in an irrigation system can be more difficult to regulate when compared to a municipal water system that has gradual fluctuations in flow rate, making the CSV an ideal choice for irrigation pressure management.

“In a golf course system, for example, the demand for water is very minimal until the irrigation system comes on. You might go from supplying 7 gallons per minute to instantly needing 2,000 gallons per minute. The CSV can respond immediately and then jump back to the 7 gallons per minute just as quickly with no ill effects to the pump or the rest of the system.”

After 23 years of installations and close to a million CSVs in operation across diverse applications, including residential, bottling plants, USDA conservation testing, treatment plants, and even NASA’s solid rocket booster, with virtually no detectable wear, Austin is confident that the valve really is, “too good to be true.” Which can be good news for cities and industries who face failing infrastructures, drought, and increased prices, and are scrambling to find inexpensive—but efficient—solutions to the challenges of water delivery. WE_bug_web

Editor’s Note: In wanting to make sure this article displays adequate objectivity, both the writer and I searched for conflicting opinions but did not find any. So while Water Efficiency magazine is not endorsing the product, we’re presenting the story as it was told to us, beginning with when the writer learned of the valves from a water utility when writing about tank coatings and out-of-service tanks. We are open to hearing from readers who have expertise with this kind of equipment, and/or personal experiences with these valves.

Comments
  • Anthony I.

    Would an electronic copy of ” Simplicity Under Pressure — The Valve That Delivers” . I have already received the magazine, ” Water Efficiency”

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  • Anthony I.

    Would like to share the article with a colleague by E-mail. How do I do that ?

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    • Hi Anthony, You can send your colleague a link to the website, letting them know that he/she will have to subscribe (free, as you know) to read the article. Just be sure to direct them to subscribe to the online magazine and not only to the website or e-newsletters. I hope this solution is do-able for you and your colleague.

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