How Californians Are Coping With the Drought

Read article : How Californians Are Coping With the Drought

Earlier this month, California Governor Jerry Brown made an unprecedented decision: To fight back the devastating effects of the drought that is currently racking the state, its citizens will be forced tocut their water use by 25 percent. It was the first such conservation mandate in the state’s history.

Though the executive order has been widely lauded for pushing the state toward a more water-conservative future, it’s still unclear exactly how it will be practically implemented. On Saturday, the State Water Resources Control Board issued arevised set of draft regulations to execute the order. In it, individual water districts are given their own water reduction targets; those areas that have historically been big water wasters will be expected to cut back the most, and those that have already shown success in conservation won’t have to reduce use significantly. (There currently are no additional cutbacks required of agricultural water users.) There is a small window of time open for public comment, and the board is expected to vote on the regulations during the first week of May.

In reality, though, the drought has already forced many Californians to adapt to a new way of life.Newsweekput out a call to residents of the state to ask them what they’ve done in the past year to adjust.  

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Rona Lewis, Nutritionist, Los Angeles

I live in an apartment, and they’ve replaced our regular toilets with low flow. Personally, I try to do little things to help: turn off the water when I’m brushing my teeth, turn it off when I’m washing my hair or waiting for the conditioner to soak in.

I’m a fitness trainer and take a lot of my clients out for power walks during the day. I see a bunch of homes with either Astroturf instead of real grass or desert-type foliage along with rocks for front lawns. It’s hard for those of us who like to grow our own food—I only have a few pots on my balcony for herbs and tomatoes, but my clients and friends who have full-fledged vegetable gardens are frustrated at the restrictions laid upon them.

What so many of us don’t understand is why there is such a fight against building desalination plants. It would solve so many water issues here!

With water in short supply, desalinization of ocean water to make it drinkable is the focus of various projects across the state. Elijah Wolfson

Brian Milne, Business Development Manager, Paso Robles

I live in wine country on the Central Coast of California where we have a ton of vineyards sucking up water and a whole host of water issues.

We had the lake in my hometown of Atascadero go dry. Lakes where I learned to fish (and have written fishing guides and hiking guides about) have gone almost dry.

Our family has cut our water use drastically. We have the brownest lawn on the block, and I'm proud of it. I've only watered our lawn once this spring, and that was when we drained our spa to irrigate our landscape. Our spa is now empty and we don't plan on using it this summer. We've also built a gray-water system that waters our roses from the washer at my parents house. We also have buckets under our rain gutters and use buckets in the shower to catch excess water and reuse it around the house when appropriate.

Additionally, I love to surf, and I've made my own portable shower out of a Roundup Weed Killer Sprayer, and put a pump and nozzle on it and use it to wash off with very little water at the beach. Many state parks in California no longer have water, or the showers they do have waste a significant amount of water. Using my portable shower, I can spread a couple gallons for about three to four showers in the mornings after surfing. That's a lot better than the American average of 17 gallons per shower!

Catherine Trainor, Startup Entrepeneur, Oakland

We bought a pump so that each time we take a bath we can pump that water into a hose to water the plants with. We have a pitcher by the sink so we can pour half-drunk water glasses, water from boiling vegetables, etc., [and use that] to water the plants. In the summer, we let our lawn die. One thing we wish we could do (and that everyone could do) would be to collect water off of our roof for when it rains. An inch of rain on our roof would give us 600 gallons of water, and we'd like to keep it!

Also coming up for the summer: bucket shower!

Hilary Achauer, Writer and Editor, San Diego

We just ripped out our front, south-facing lawn and installed California native plants. We did not install irrigation. The plan is to water it twice a week for eight weeks, and then it should be established well enough that it won't need watering. We've even got some trees—two shoestring acacia trees and an incredible paloverde tree, which is a desert tree with lovely yellow flowers.

Chantay Bridges, Realtor, Los Angeles

At first, I was not dealing with it at all. I heard about it, I felt it, I saw the effects of it. Originally, I sort of buried my head in the sand and attempted to ignore it. Now that it's at a massive level and mandates are being formed, I have taken a look at it more closely. Here's now how we are dealing with the impact of the California drought:

We have reduced our water usage. In lieu of washing daily, even if it's one blouse, we now only wash once per week as an entire family We have adjusted our automatic water sprinklers. Now there are a couple of days where the lawn is not being watered at all. We are not encouraging water type of games with the kids and their friends. Instead, we have given them other options, despite the nice weather.

We are talking to our neighbors, friends and co-workers soliciting suggestions of more ways to conserve. We attended a few neighborhood meetings where they discussed it in length, to educate ourselves and learn best practices.

We are shopping more for water and keep an emergency supply in the home.

Some Californians have stopped watering lawns and plants and others have reduced how often they run sprinklers. Elijah Wolfson

V.J. Sleight, Smoking Cessation Counselor, La Quinta

I have cut the size of my lawn by 75 percent, and I am considering getting rid of the rest of it. I've stopped taking showers every day, especially since some days the only exertion I get is sitting at a desk. I contacted the local water agency, which gave me low-flow nozzles for shower and sinks, plus a plastic bag for the toilet to reduce the amount of water used. I use a dry brush on my car instead of always getting a car wash.

John Cox, Chef, Big Sur

This week [at the Post Ranch Inn], we started using compressed air to clean the plates before loading them into the dish machine. Traditionally, the spray nozzle at the dish station is one of the kitchen's biggest uses of water. By adding the compressed air gun to the station, we have been able to reduce the usage of the water in that area by 80 percent and actually increase productivity. That is a huge savings!

Natalie Nicole Gilbert, Singer/Songwriter, Los Angeles

We received pamphlets last year asking us to avoid water usage during the day as much as possible, such as we would use for laundry, dishwashers, etc. We've since started washing dishes by hand, waiting until a laundry basket is full to do laundry, kept a tighter eye on leaks and drips from the faucets, and generally cut back our water usage on every front we can easily control.

When my doctor advised I take lengthy showers to combat my bronchitis and borderline pneumonia, I balanced that advice with using a small facial and sinus steamer that had much the same effect but required less than one cup of water to create the steam.

We have also thought about moving out of state, particularly because the drought shows no signs of improvement anytime soon. We've begun circulating résumés as far away as the U.K. and Denmark.

Gretchen Hydo, Public Relations Professional, Sherman Oaks

To reduce water, we have cut back on laundry and are wearing our clothes more, flushing toilets less, and watering less. I am a life coach who works from home and my clients come to the house. I did not want to let my garden or my lawn go because it doesn’t look very appealing. The guilt I was having about watering and planting was taking its toll. I called a landscaper to see about drought-tolerant plants (I do not think they are appealing at all, but needed to do something). He came over, and after talking I discovered that I could keep my lawn and my plants and save up to 40 percent of water. It sounded too good to be true, but it worked.

Here are the things we did: 

• We put in a drip system.
• In our flower garden we put in water beads that expand 300 percent. They hold water so that you can water less (and the plants still receive water).
• We put in some individual sprayers to the root balls of the plants so that they got the water (that is all that needs the water to grow).
• We mulched.
• We put in a tank that automatically feeds the lawn and flowers bio stimulants—this makes the flowers bloom, keeps them healthy and keep the grass green. It also cuts down on the water
• And…..I did put in some colorful, drought tolerant plants

Our yard looks amazing.

Liam Collopy, Communications Executive, Manteca

We recently had a pool company come to our home—which routinely reaches 100-degree temperatures in the summer—to provide a design plan and estimate. With the drought and pending water restrictions, we've had to seriously rethink. In addition, the future of our well-manicured plush green front lawn-which is watered according to preset timers—is quickly becoming an offensive luxury as the drought lingers.

This is the new normal in the Central Valley of California. Appearance is out. Water efficiency and conservation is in.

I'm saddened not only for the farmers in our region but for future generations. I'm not an alarmist but my fear is California is turning into a desert.

Nigel Ravenhill, IT Marketing Specialist, Napa

Drought has made me way, way more conscious of even wasting a little bit of water. Now, if there's some water left in a drinking glass, instead of pouring it down the drain, I either water plants inside or walk outside and empty it in one of our outdoor planters or over our potted meyer lemon tree.

Similarly, I don't let the water go straight down the drain if I'm running the tap to get hot water to wash the dishes. Instead of letting a gallon go down the drain, I'll refill the electric kettle or fill-up jugs for watering the plants before the hot water arrives in the tap.

I had almost a crisis of conscience last Saturday morning after having an ice bath following a hard running workout. I was very tempted afterwards to get a bucket from the garage and move the however many gallons from the second floor bathroom to the garden for watering. My wife ended up pulling the plug later in the day.

All three of these behaviors wouldn't have earned a second thought in previous years.

Finally, we're also thinking of removing the front-yard lawn but we live in a neighborhood with restrictions on landscaping options so we're not even sure this will be possible.

And that's what life is now like in California.

Is water the next 'drug' for Mexico’s cartels?

Read article : Is water the next 'drug' for Mexico’s cartels?

Aug 14, 2017

What it's like when narcos run your privatized water system, Tamara Pearson reports.

A pipa, or water truck, filling up the underground well for shops in Puebla city. Credit: Tamara Pearson

It's rainy season here in Puebla, Mexico, and water is dripping through my concrete roof, taking chunks of plaster and paint from the ceiling with it. Ironically, we still don't have enough running water to shower everyday. Other people here have no running water at all, and our drainage system is in a state of utter abandonment.

Yet we all pay 10 times the rates of the rest of Mexico, because here in Puebla – unlike the rest of the country – our water is privatized. What's more, the men at the helm of the consortium that run it are a collection of corrupt millionaire and billionaire businessmen who have allegedly laundered money for some of the region's biggest drug cartels.

Throughout much of Mexico large, usually black, tinacos (water tanks) dot the roof tops of our concrete slums and towns. A lot of us have running water for just 15-30 minutes, twice a week, so we fill up the tinacos to cover the rest of the time. Many of the older tanks are made of asbestos, while the newer ones are a solid black plastic. A friend who lives around the corner has only a large container of water in his bathroom, while those in wealthier areas often have underground storage and much more regular water.

Most of us, however, have just 400 litres of water to last the household a week. In the US, a single person consumes that amount per day. In my home, we wash our clothes in a bucket, recycle that water to flush the toilet, collect the water from the shower for flushing, and only flush around once or twice a day. Showers are quick and had every three days or so.

My water bill is 630 pesos per month, while in neighboring Tlaxcala state, people pay 50 pesos per month. Everyone here has stories of being unfairly charged for water, or of going without any water for a year or two – despite constant complaints to the water company, Aguas de Puebla.

I was duly awarded a debt of 115,000 pesos when I first moved into my tiny apartment, located in the poor side of inner-city Puebla. For perspective, that's nearly four years’ worth of minimum wage. I spent four months battling the water company to get that corrected – spending 45 minutes each way on public transport to talk to them directly in their head office, and ringing them on a daily basis. Each time, they asked me to bring in more documents, placing the paperwork burden on me, instead of on themselves as the ones who made the mistake. They gave me excuses and promises that it would be resolved in three weeks’ time and to come back then, and even redirected me to other departments – ‘I'll put you through to water meters, maybe they can help with your case.’

Ultimately, some firm phone calls to the head of public relations of the company, with support from an incredible journalist friend, saw me meeting directly with PR, finally, the figure was fixed in their system in a matter of minutes. At the time, I put it down to the bureaucratic, inhumane habits of private corporations, but later I would realize just how much more sinister the problem was.

Water tanks on the rooftops of inner-city Puebla. Credit: Tamara Pearson

Illegal privatization

‘Baja California was the first state in Mexico to plan to privatize its water, but protests and resistance stopped that. Puebla was the second state,’ Fernando, an indigenous water activist in the Peoples Against the Privatization of Water group told me. He asked that I not include his last name, given the arrest warrants pending on a number of water activists, and the risk involved.

In 2013, the Puebla state government justified the privatization of water by arguing that the incoming company would invest the money necessary to improve the service, eliminate leaking pipes that saw 30 per cent of all water lost, and expand the reach of piped water. It passed the Water Law, that would allow the new company to set prices without oversight and to hire other private companies, and put out a call for bids in September that year. The government awarded the bid to Concessions Integrales, also known as Aguas de Puebla, three days before the consortium was actually formed and legally able to participate in a bid for tender. Though the governor had talked about a 30 year deal, that was extended to 60 years.

Narco business

No one imagined that one of the main companies behind Enrique Peña Nieto's presidential election campaign in 2012 would ultimately end up running Puebla's water supply system, in a consortium made up of other corrupt and scandalous companies.

Monex, Epccor, and Grupo Financiero Interacciones are the main companies involved in Aguas de Puebla, though reports of their exact shares in ownership vary. Monex itself told the press that it owned a ‘third’, but added that exactly who has how many shares was a ‘banking secret’.

Monex made news at the time for running Peña Nieto's campaign strategy of buying votes through the distribution of pre-paid cards, and funneling money to his campaigning fund. Reports suggest that this money, however, likely came from the Juarez Cartel – one of the oldest and most powerful criminal organizations in the country.

Mexico's election court ultimately ruled that there hadn't been any fraud, but many are skeptical of this ruling because Mexico's courts are known for their extremely high levels of corruption and political interference. Additionally, it wasn't the first time that Monex had allegedly been involved with major drug cartels. An investigation conducted by newspaper Reforma found a working relationship with the Arellano Feliz cartel in 2003, and with the Colombian cartel, Valle del Norte, in 2006. In 2008, Spanish authorities found that the Beltran Leyva cartel had changed some 78 million euros through Monex and a company called Intercam.

Epccor is owned by Juan Gutierrez, who is also president of Aguas de Puebla, and who also owned the company Gutsa, a key financial backer of the 1994 PRI presidential campaign (Peña Nieto's party). Gutierrez's companies have been repeatedly fined for mismanagement. Epccor, with it connections in the government, regularly receives contracts for public works like hospitals, roads, and airports; consistently spends more than it originally declared in its budget, and delays completion by years. The most recent case was a hospital which has spent nine years so far under construction, and still isn't finished.

Grupo Financiero Interacciones, run by the infamously corrupt and excessive rich Hank family, has strong links to the PRI and to the Juarez Cartel. Grandfather Hank, Carlos Hank Rhon, is a billionaire, and his family has been the subject of numerous reports of drug laundering on a massive scale, as well as assisting cartels with drug shipments, and large-scale public corruption. A World Policy Report from 1995 went so far as to describe Carlos Hank as the "primary intermediary between the multinational drug trafficking enterprises and the Mexican political system,” and Hank has been investigated for money laundering by Mexican, Swiss, and French judges.

One key strategy Hank is alleged to have used, was to buy food products with the money cartels made from selling cocaine in the US. Hank's companies had a monopoly on these food products, which they then sold back in Mexico. The Hank family has also colluded with Mexican state authorities to gain permits for their rooster fighting and horse racing, and to get significant debts pardoned. Son Jorge Hank Rhon has also been accused of using the gambling business for drug trafficking links and to launder money.

An Aguas de Puebla office. Credit: Tamara Pearson

A broken system

With corrupt narcos running Puebla’s water, it's no surprise that the system is beyond dysfunctional. People have accused the company of charging for non-existing debts, of water supply issues and random bill increases, and of charging up to 3,000 pesos (a good month's wage) for meters to be installed. Some areas are supplied with contaminated water, whole suburbs have gone without water for weeks, the company charges to check people's broken connections, and people report that their meters aren't working but the company refuses to repair them and keeps charging an incorrect rate. People facing errors like mine tend to wait a year for a resolution, if they get any at all.

In May this year, communities from the south of the city protested and closed roads after going weeks without water, while Aguas de Puebla still charged them for it. They said that when they did get water, it ‘smelt bad and was yellow,’ while other communities went for three months without water because the company couldn't be bothered to fix the pump.

Businesses have also complained about large bills, pointing out at least six companies in the city that have monthly bills that amount to millions in pesos, ‘without a clear explanation why,’ they told a press conference.

Internally, workers at Aguas de Puebla have also complained stating that they were threatened with being fired on a daily basis and weren't paid promised bonuses. They said they were told not to inform people how rates were calculated, leading to people paying more than they should and they also claimed that the company had cut the petrol budget for company vehicles by 60 per cent, making it difficult for workers to go out and do repairs.

Aguas de Puebla does roll out the red carpet for some of its clients, however. ‘Many years ago, governor Mario Marin signed an agreement with Nealtican and Santa Maria Acuexcomac – towns in the valley of the Popo volcano – for their water,’ Fernando said. In exchange, the towns got sports courts and roads, but their good quality water is delivered by Aguas de Puebla to the wealthy part of town – Angelopolis, while ‘the worst water goes to the poor suburbs, where there's scarcity.’

Jugs of water for sale. Credit: Tamara Pearson

Nothing lives without water

‘We can live without petrol, without electricity, but not without water. The government and the companies it colludes with think to themselves, if petrol is hugely profitable, how much money can you make from water?’ Fernando explained.

Indeed, even before the narco companies took over our water, it was already a big-profit industry and essentially privatized. Those facing water shortages, and those who can't drink their piped water, are forced to buy bottled water from private companies.

In 2014, Mexico was the largest consumer of bottled water in the world with almost US$8 billion in revenue that year and 234 liters consumed on average per person annually. The companies dominating the bottled water industry here are Danone (47 per cent), Coca-Cola (19.4 per cent) and Epura (7.1 per cent). Many people buy water in 20 litre jugs, or garafones, and in that case, small, local water providers account for around half of the market.

People lacking piped water will also pay pipas – large trucks that look a bit like tanker trucks – to pump water into their roof-based plastic water tanks. In Mexico City, some 40 per cent of water distributed this way is sold illegally.

The bottled water companies have also waged marketing campaigns to promote distrust in the quality of piped water.

Across Mexico, some 9 million people have no water pipes in their homes and a further 13 million people have piping, but the water is contaminated and leads to skin conditions and gastrointestinal infections. Seventy-five percent of the population live with water scarcity, but big business won't be offering a hand any time soon.

Tamara Pearson is a long time journalist based in Latin America, alternative pedagogy teacher, and author of The Butterfly Prison. She blogs at Resistance Words.

Patent US20110089249 - Thermostatic mixing valve with pressure reducing element

Read article : Patent US20110089249 - Thermostatic mixing valve with pressure reducing element

TECHNICAL FIELD

[0001]

The present disclosure relates generally to the field of mixing valves and more particularly to thermostatic mixing valves.

BACKGROUND

[0002]

Thermostatic mixing valves are used in a wide variety of applications for mixing fluids of dissimilar temperatures to produce a tempered fluid discharge output temperature. For example, and in one illustrative application, thermostatic mixing valves can be used in conjunction with water heaters. Water heaters are frequently used to supply hot water to desired locations within a house, office building, or other structure. To regulate the temperature of water discharged by the water heater, a thermostatic mixing valve can be connected to the hot water outlet of the water heater, allowing hot water discharged from the water heater to be mixed with cold water supplied to the structure to produce a relatively constant tempered discharge output temperature. The tempered water discharged from the mixing valve can be fed into the structure's hot water piping for subsequent use by the occupants. Often, a goal of such mixing valves is for the temperature of the mixed water to remain constant or nearly constant regardless of the temperature, pressure and/or flow rate of the hot and cold water supplied to the mixing valve.

SUMMARY

[0003]

The disclosure relates generally to thermostatic mixing valves, and more particularly to thermostatic mixing valves that are configured to provide improved temperature stability of the mixed water stream at the outlet of the mixing valve given variations in the temperature and/or pressure of the hot and/or cold water supplies to the valve, while still achieving relatively high flow rates through the valve. In one illustrative and not-limiting example, a thermostatic mixing valve may include a cold fluid inlet for passing a flow of cold fluid, a hot fluid inlet for passing a flow of hot fluid, and an outlet for passing a flow of mixed tempered fluid. A fluid flow regulator may be provided to regulate the relative flow of cold fluid from the cold fluid inlet and hot fluid from the hot fluid inlet to produce the flow of tempered fluid at the outlet of the valve. A pressure reducing element may be situated in the hot fluid inlet upstream of the fluid flow regulator. It has been found that such a pressure reducing element may, for example, help increased the temperature stability of the tempered fluid at the valve outlet given variations in the temperature and/or pressure of the hot and/or cold fluids presented at the hot fluid inlet and the cold fluid inlet of the valve.

[0004]

The above summary is not intended to describe each and every disclosed embodiment or every implementation of the disclosure. The Description that follows more particularly exemplifies various illustrative embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

[0005]

The disclosure may be more completely understood in consideration of the following detailed description of various embodiments in connection with the accompanying drawings, in which:

[0006]

FIG. 1 is a perspective view of an illustrative but non-limiting thermostatic mixing valve;

[0007]

FIG. 2 is a partial cross-sectional view of the illustrative thermostatic mixing valve of FIG. 1, showing an illustrative pressure reducing element;

[0008]

FIG. 3 is a front elevation view, with parts in cross-section, of another illustrative thermostatic mixing valve;

[0009]

FIG. 4 is a cross-sectional view of the illustrative thermostatic mixing valve of FIG. 3 shown an illustrative a pressure reducing element;

[0010]

FIG. 5 is a side view of another illustrative thermostatic mixing valve with a secondary hot port;

[0011]

FIG. 6 is a partial cross-sectional view of the illustrative thermostatic mixing valve of FIG. 5 showing an illustrative pressure reducing element; and

[0012]

FIG. 7 is a schematic view showing an illustrative water heater system employing a thermostatic mixing valve.

[0013]

While the invention is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit aspects of the invention to the particular illustrative embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

DESCRIPTION

[0014]

The following description should be read with reference to the drawings in which similar elements in different drawings have similar reference numbers. The description and the drawings, which are not necessarily to scale, depict illustrative embodiments and are not intended to limit the scope of the invention. The illustrative embodiments depicted are intended only as exemplary. Selected features of any illustrative embodiment may be incorporated into other embodiments unless clearly stated to the contrary.

[0015]

All numeric values are herein assumed to be modified by the term “about”, whether or not explicitly indicated. The term “about” generally refers to a range of numbers that one of skill in the art would consider equivalent to the recited value (i.e., having the same function or result). In many instances, the term “about” may be indicative as including numbers that are rounded to the nearest significant figure. The recitation of numerical ranges by endpoints is intended to include all numbers within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5).

[0016]

Although some suitable dimensions, ranges and/or values pertaining to various components, features and/or specifications are disclosed, one of skill in the art, incited by the present disclosure, would understand desired dimensions, ranges and/or values may deviate from those expressly disclosed.

[0017]

FIG. 1 is a perspective view of an illustrative but non-limiting thermostatic mixing valve 2. The illustrative thermostatic mixing valve 2 includes a valve body 10 that has a hot fluid inlet 16, a cold fluid inlet 18 and a mixed fluid outlet 20. The hot fluid inlet 16 is configured to receive fluid at an elevated temperature from, for example, a water heater, a boiler, or any other suitable heating source, and can include a tailpiece fitting (not shown) or other suitable connector for connecting the hot fluid inlet 16 to the supply (e.g. pipe) of hot fluid. Likewise, the cold fluid inlet 18 is configured to receive colder fluid from, for example, a cold water supply, and can include a tailpiece fitting 19 or other suitable connector for connecting the cold fluid inlet 18 to the supply (e.g. pipe) of colder fluid.

[0018]

In the illustrative embodiment, the mixed fluid outlet 20 is configured to output a fluid that is a mixture of the hot fluid received at the hot fluid inlet 16 and the colder fluid received at the cold fluid inlet 18, resulting in a discharge fluid having a tempered discharge temperature. The tempered mixed fluid outlet 20 may be fluidly connected to the hot water piping of a building or other structure, and can include a tailpiece fitting 21 or other suitable connector similar to that provided for the hot and cold fluid inlets 16, 18. A fluid flow regulator (not explicitly shown in FIG. 1) may be positioned in the valve body 10 to regulate the relative flow of cold fluid from the cold fluid inlet 18 and hot fluid from the hot fluid inlet 16 to produce the flow of tempered fluid at the outlet 20. The fluid flow regulator may be a thermally controlled fluid regulator, similar to the fluid flow regulator 190 shown and described below with respect to FIG. 4. A pressure reducing element may be formed in the hot fluid inlet upstream of the fluid flow regulator, as will be discussed in more detail with respect to FIG. 2.

[0019]

In some cases, the mixing valve 2 may also include an optional recirculation inlet 22 configured to receive tempered water from the water piping of the building or other structure, and can include a tailpiece fitting (not shown) or other suitable connector. The recirculation inlet 22 may be used to recirculate water that has previously been delivered to the hot water piping back to the mixing valve 2. The recirculation inlet 22 may be useful in ensuring that hot water at the tempered temperature is immediately available at a desired location within the building, such as in a shower or the like.

[0020]

The illustrative thermostatic mixing valve 2 also includes an optional secondary hot port 24 for providing hot water directly to an appliance or other fixture that can use non-tempered hot water (e.g. water provided directly from a water heater or the like). For example, the optional secondary hot port 24 may be used to supply non-tempered hot water to a dishwasher, a clothes washer, a humidifier, and/or any other suitable appliance, fixture or device, as desired. The secondary hot port 24 may reduce or eliminate the need for a separate “T” connector off of the water heater source. The secondary hot port 24 can include a tailpiece fitting (not shown) or other suitable connector. The tailpiece fittings may each include a union sweat fitting, threaded fitting (e.g. NPT, NPS, etc.), compression fitting, PEX fitting, and/or any other suitable fitting that can be used to connect the various inlets and outlets of the mixing valve 2 to the other components of the installed system. A threaded coupling (not shown) can be used to secure each of the tailpiece fittings 19, 21 to the valve body 10, if desired.

[0021]

As can be further seen in FIG. 1, the illustrative thermostatic mixing valve 2 may have a configuration wherein the hot fluid inlet 16 and mixed fluid outlet 20 are vertically and axially aligned along an axis L of the longitudinal portion of valve body 10. This may allow the mixing valve to be mounted “in line” with a water heater hot water outlet pipe, which can simplify installation in some cases. The cold water inlet 18, in turn, may enter the valve body 10 at an angle along axis A, or any angle desired, to the side housing 13. In some embodiments, the cold water inlet 18 may enter the valve body 10 at an angle orthogonal to the longitudinal axis L to permit direct access to the cold water inlet port provided on many conventional water heaters, as described in copending U.S. patent application Ser. No. 12/273,370, filed Nov. 18, 2008, entitled “Thermostatic Mixing Valve with Secondary Hot Port”, which is incorporated by reference.

[0022]

In the illustrative embodiment of FIG. 1, recirculation inlet 22 is shown entering the valve body 10 at an angle orthogonal to the longitudinal axis L, but in a direction opposite that of the cold water inlet 18. In some cases, recirculation inlet 22 may enter valve body 10 at a different angle. While mixing valve 2 is shown as having recirculation inlet 22, the recirculation inlet 22 is optional and thus may be excluded. Likewise, the secondary hot port 24 may exit the valve body 10 at an angle orthogonal to the longitudinal axis L to permit direct access to the secondary hot port 24. In the illustrative embodiment, the secondary hot port 24 is positioned at a location upstream from a mixing chamber such that non-tempered hot water is available directly from the hot water source. As with the recirculation inlet 22, the secondary hot port 24 is optional and not required.

[0023]

During operation, the mixing valve 2 can be adjusted to proportionately mix cold and hot water received at each of the water inlets 16,18, which can then be outputted as tempered water at a relatively constant, pre-selected temperature through the mixed water outlet 20. In certain applications, for example, the mixing valve 2 can be configured to output water at a relatively constant or mixed water temperature of about 120° F., while permitting a water heater to operate at elevated temperatures in the range of, for example, about 120° F. to 180° F.

[0024]

As discussed above, some water heaters may be configured to produce hot water that is at a temperature that is significantly hotter than that desired in the structure's hot water piping. By increasing the temperature of the water supplied by the water heater, a greater amount of cold water may be mixed with the hot water to increase the effective heating capacity of the water heater. Also, some water heaters operate at a higher efficiency when the operating temperature is elevated. For example, in an 80-gallon water heater, such an increase in the operating temperature may result in an increase in the effective hot water capacity that is similar to that of a 120-gallon water heater operating at a lower temperature. It should be understood, however, that the thermostatic mixing valve 2 and/or water heater can be configured to operate at other temperature ranges, as desired.

[0025]

In the illustrative embodiment of FIG. 1, a temperature adjustment device 12 is disposed within a side housing 13 of the valve body 10, and can be provided to adjust the temperature of tempered fluid discharged from the mixing valve 2. In residential water heating systems, for example, the temperature selection device 12 can be used to adjust the thermostatic mixing valve 2 to output tempered water at a set-point temperature in the range of about 70° F. to 145° F., 70° F. to 120° F., 90° F. to 130° F., or any other temperature range as desired. The set-point temperature selected by the temperature selection device 12 may vary based on the application. In the illustrative embodiment, the temperature adjustment device 12 includes a hand wheel 14 that can be manually turned by a user. However, it is contemplated that the illustrative temperature adjustment device 12 may include any suitable mechanism for adjusting the set-point of the mixing valve 2. When provided, temperature adjustment device 12 may be similar to that described in copending U.S. patent application Ser. No. 12/273,307, filed Nov. 18, 2008, entitled “Thermostatic Mixing Valve with Tamper Resistant Adjustment Feature”, which is incorporated by reference.

[0026]

FIG. 2 is a partial cross-sectional view of the illustrative thermostatic mixing valve of FIG. 1, showing an illustrative pressure reducing element 15. The fluid flow regulator of the thermostatic mixing valve has been removed for clarity. When not removed, the fluid flow regulator would be situated in the cavity labeled 17. As can be further seen in FIG. 2, the illustrative thermostatic mixing valve 2 has a configuration wherein the hot fluid inlet 16 and tempered or mixed fluid outlet 20 are vertically and axially aligned along an axis of the longitudinal portion of valve body 10, but this is not required. This may allow the mixing valve to be mounted “in line” with a water heater hot water outlet pipe, which can simplify installation in some cases. The cold water inlet (not shown in FIG. 2), in turn, may enter the valve body 10 at an angle orthogonal to the longitudinal axis “L” (see FIG. 1) to permit direct access to the cold water inlet port provided on many conventional water heaters.

[0027]

The illustrative thermostatic mixing valve 2 also includes a pressure reducing element 15 that is situated in the hot fluid inlet port 16 upstream of chamber 17, which if shown, would house the fluid flow regulator. The pressure reducing element 15 may include, for example, a pressure reduction disk or snubber element 15 that defines an aperture with a cross-sectional area, such as an aperture with a diameter “D”. In some embodiments, pressure reducing element 15 may be integrally formed with the valve housing 10. In other embodiments, the pressure reducing element 15 may be a separate component that is fitted in the hot fluid port 16. In some embodiments, hot fluid inlet port 16 may have a first cross-sectional area upstream of the pressure reducing element 15. The first cross-sectional area of the hot fluid inlet port 16 may be greater than the cross-sectional area of the aperture of the pressure reducing element 15. In some cases, the cross-sectional area of the hot fluid inlet port 16 may be configured to facilitate connection with a hot fluid supply. In some cases, the pressure reducing element 15 may be situated a distance downstream of the entry of the hot fluid inlet port 16, and downstream of the mixing chamber 17 as shown in FIG. 2.

[0028]

Pressure reducing element 15 may define an aperture having a cross-sectional area that is smaller than the cross-sectional area of hot fluid inlet port 16. In some instances, the cross-sectional area of the aperture of the pressure reducing element 15, illustrated by diameter D in FIG. 2, may be 80% or less, 60% or less, 40% or less, or 20% or less, of the cross-sectional area of the hot fluid inlet port 16 upstream of the pressure reducing element 15. In the illustrative embodiment, the diameter D of the aperture of the pressure reducing element 15 may be set to any suitable value, depending on the desired flow rate through the mixing valve 2. For example, the diameter D may be smaller than 0.10 inches, 0.10 inches, 0.20 inches, 0.30 inches, 0.4 inches or larger depending on the application. In one example, the cross-sectional area of the hot fluid inlet port 16 upstream of the pressure reducing element 15 may be greater than about 0.12 inches square, and the cross-sectional area of the aperture at the pressure reducing element 15 may be less than about 0.07 inches square. In another example, the cross-sectional area of the hot fluid inlet port 16 upstream of the pressure reducing element 15 may be greater than about 0.19 inches square, and the cross-sectional area of the aperture at the pressure reducing element 15 may be less than about 0.13 inches square.

[0029]

In yet another example, the cold fluid inlet 18 (see FIG. 1) of the thermostatic mixing valve 10 may be dimensioned to pass a first flow rate of cold fluid when the cold fluid is presented to the thermostatic mixing valve at a first pressure. The hot fluid inlet 16 of the thermostatic mixing valve 10 may be dimensioned to pass a second flow rate of hot fluid when the hot fluid is presented to the thermostatic mixing valve at the same first pressure. In some cases, the second flow rate is less than 80% of the first flow rate, sometimes due to the presence of a pressure reducing element 15 or some other feature of the hot fluid inlet 16 and no equivalent feature in the cold fluid inlet. In other cases, the second flow rate may be less than 60%, less than 40%, less than 20% or even less than the first flow rate, depending on the application.

[0030]

While the aperture in pressure reducing element 15 of FIG. 2 is illustrated as a circular aperture, it is contemplated the aperture may be of any suitable shape including, for example, square, elliptical, rectangular, or polygonal. In some embodiments, pressure reducing element 15 may be formed of brass, however, it is contemplated that the pressure reducing element 15 may be formed of any suitable material or material combination as desired, such as, but not limited to other metals, metal alloys, elastomers, and/or plastics. The material of the pressure reducing element 15 may be selected in accordance with the environment in which the valve may be used.

[0031]

The illustrative mixing valve 2 of FIG. 2 may also include an optional secondary hot port 24 for providing hot water directly to an appliance or other fixture that can use non-tempered hot water (e.g. water provided directly from a water heater or the like). As can be seen in FIG. 2, the secondary hot port 24 may be disposed at a location upstream of the mixing chamber 17 such that non-tempered water may be available directly from the mixing valve 2. In some cases, such an optional secondary hot port 24 may be used to supply non-tempered hot water to a dishwasher, a clothes washer, a humidifier, and/or any other suitable appliance, fixture or device, as desired. The secondary hot port 24 may reduce or eliminate the need for a separate “T” connector off of the water heater source.

[0032]

FIG. 3 is a front elevation view, with parts in cross-section, of another illustrative thermostatic mixing valve. While the configuration of mixing valve 102 in FIG. 3 is somewhat different from that of mixing valve 2 of FIGS. 1-2, its general function is similar. Similar to that discussed above with respect to FIG. 1, mixing valve 102 of FIG. 3 has a hot fluid inlet 116, a cold fluid inlet 118, and a mixed fluid outlet 120. The hot fluid inlet 116, cold fluid inlet 118, and mixed fluid outlet 120 can each include a tailpiece fitting 117,119,121 or other suitable connector for connecting the inlet ports 116,118,120 to a water system. For example, threaded couplings 146 can be used to secure each of the tailpiece fittings 117,119,121 to the valve body 110, but this is not required. It is contemplated that the mixing valve 102 may also include an optional recirculation inlet (not shown) configured to receive tempered water, and can include an associated tailpiece fitting (not shown) or other suitable connector. Similar to the embodiment shown in FIG. 1, mixing valve 102 may include an optional secondary hot port (not shown) for providing hot water to appliances or other fixtures that do not require tempered hot water, such as but not limited to dishwashers, clothes dryers, humidifiers, etc.

[0033]

As can be further seen in FIG. 3, the mixing valve 102 may have a vertical, in-line configuration wherein the hot fluid inlet 116 and mixed fluid outlet 120 are vertically and axially aligned along an axis L of the valve body 110. As discussed above, this may allow the mixing valve to be mounted “in line” with a water heater hot water outlet pipe, which can simplify installation. As shown, the cold water inlet 118, in turn, may enter the valve body 110 at an angle orthogonal to the longitudinal axis L to permit direct access to the cold water inlet port provided on many conventional water heaters. The recirculation inlet, when provided, may enter the valve body 110 at an angle orthogonal to the longitudinal axis L, but in a direction opposite that of the cold water inlet 118, or any other desired location. The secondary hot port, when provided, may exit the valve body 110 at an angle orthogonal to the longitudinal axis L to permit direct access to the secondary hot port, but this is not required. While an in-line configuration is shown in FIGS. 1 and 3, it is contemplated that the mixing valve may have any suitable configuration including a “T” configuration or any other suitable configuration as desired. In a “T” configuration, a hot fluid inlet and a cold fluid inlet may enter the valve body from left and right sides, respectively, and a mixed fluid outlet may exit the valve body in a downward direction. This is just another example configuration that may be used.

[0034]

Similar to the embodiment described in FIG. 1, during operation, the mixing valve 102 can be adjusted to proportionately mix hot and cold water received at each of the water inlets 116,118, in order to provide tempered water at a relative constant temperature through mixed water outlet 120. As previously discussed, in certain applications, for example, the mixing valve 102 can be configured to output water at a relatively constant mixed water temperature of about 120° F., while permitting a water heater to operate at elevated temperatures in the range of, for example, about 120° F. to 180° F. It should be understood, however, that the mixing valve 102 and/or water heater can be configured to operate at other temperature ranges, if desired.

[0035]

As shown in FIG. 3, a temperature adjustment device 112 may be disposed within a side housing 113 of the valve body 110. The temperature adjustment device 112 can be used to adjust the temperature of fluid discharged from the mixed fluid outlet 120 of the mixing valve 102. In residential water heating systems, for example, the temperature adjustment device 112 can be used to adjust the mixing valve 102 to output tempered water at a set-point temperature in the range of about 70° F. to 145° F., 70° F. to 120° F., 90° F. to 130° F., or within any other suitable range, as desired. The set-point temperature selected by the temperature adjustment device 112 may vary depending on the application. In the illustrative embodiment, the temperature adjustment device 112 may include a hand wheel 114 for adjusting the set-point of the mixing valve 102.

[0036]

FIG. 4 is a cross-sectional view of the illustrative thermostatic mixing valve of FIG. 3 shown an illustrative a pressure reducing element 115. As shown in FIG. 4, the hot fluid inlet 116 of the valve body 110 may include gasket 108 adapted to frictionally secure a tailpiece fitting 117 to the valve body 110. The tailpiece fitting 117, in turn, can be secured to the valve body 110 using a threaded coupling 146. Such a configuration may permit the tailpiece fitting 117 to be separately connected to a pipe or a conduit supplying hot water from a water heater or the like, and attached thereto using the threaded coupling 146. A similar arrangement can be provided for connecting tailpiece fittings to the cold fluid inlet 118 and mixed fluid outlet 120, if desired.

[0037]

The illustrative mixing valve 102 also includes a pressure reducing element 115. Pressure reducing element 115 may be an annular pressure reduction disk defining an aperture with a diameter D1 disposed in the hot fluid inlet port 116. In some embodiments, pressure reducing element 115 may be integrally formed with the valve housing 110. In other embodiments, the pressure reducing element may be a separate component press fit or otherwise provided in the hot fluid port 116. In some embodiments, hot fluid inlet port 116 may have a first cross-sectional area different from the cross-sectional area defined by the aperture in pressure reducing element 115. In some cases, the cross-sectional area of the hot fluid inlet port 116 upstream of the pressure reducing element 115 may be configured to more easily connect to a hot fluid supply pipe. Pressure reducing element 115 may be positioned a distance downstream from the entry of the hot fluid inlet port 116, but upstream of a fluid flow regulator 190.

[0038]

Pressure reducing element 115 may define an aperture having a cross-sectional area (illustrated by diameter D1 in FIG. 4) that is less than the cross-sectional area of hot fluid inlet port 116 upstream of the pressure reducing element 115. In some instances, the cross-sectional area of the aperture of the pressure reducing element 115 may be 80% or less, 60% or less, 40% or less, or 20% or less, of the cross-sectional area of the hot fluid inlet port 116 and/or the cold fluid inlet port 118. The cross-sectional area of the aperture of the pressure reducing element 115 may be set depending on the desired flow rate through the mixing valve 102. For example, in the illustrative embodiment of FIG. 4, the diameter D1 of the pressure reducing element 115 may be smaller than 0.10 inches, 0.10 inches, 0.20 inches, 0.30 inches, 0.4 inches, or larger depending on the application. In one example, the cross-sectional area of the hot fluid inlet port 116 upstream of the pressure reducing element 115 may be greater than about 0.12 inches square, and the cross-sectional area of the aperture at the pressure reducing element 115 may be less than about 0.07 inches square. In another example, the cross-sectional area of the hot fluid inlet port 116 upstream of the pressure reducing element 115 may be greater than about 0.19 inches square, and the cross-sectional area of the aperture at the pressure reducing element 115 may be less than about 0.13 inches square.

[0039]

In yet another example, the cold fluid inlet 118 of the thermostatic mixing valve 102 may be dimensioned to pass a first flow rate of cold fluid when the cold fluid is presented to the thermostatic mixing valve at a first pressure. The hot fluid inlet 116 of the thermostatic mixing valve 102 may be dimensioned to pass a second flow rate of hot fluid when the hot fluid is presented to the thermostatic mixing valve at the same first pressure. In some cases, the second flow rate is less than 80% of the first flow rate, sometimes due to the presence of a pressure reducing element 115 or some other feature of the hot fluid inlet 116 and no equivalent feature in the cold fluid inlet 118. In other cases, the second flow rate may be less than 60%, less than 40%, less than 20% or even less than the first flow rate, depending on the application.

[0040]

While the aperture in pressure reducing element 115 of FIG. 4 is illustrated as a circular aperture, it is contemplated the aperture may be of any suitable shape including, for example, square, elliptical, rectangular, or polygonal. In some embodiments, pressure reducing element 115 may be formed of brass, however, it is contemplated that the pressure reducing element 115 may be formed of any suitable material or material combination as desired, such as, but not limited to other metals, metal alloys, and/or plastics. The material of the pressure reducing element 115 may be selected in accordance with the environment in which the valve may be used.

[0041]

The fluid flow regulator 190 of FIG. 4 thermostatically adjusts the flow of cold and hot fluid injected into a mixing chamber 160 of the valve body 110. In the illustrative embodiment, the fluid flow regulator 190 includes a spool 162, a modulating spring 164, a piston stem 166, a bypass spring 168, a diffuser 170, and a temperature sensitive (e.g. wax filled) thermal element 172. The spool 162 may be movably disposed between a first inner surface 174 of valve body 110 and a second inner surface 176 of the valve body 110 in a direction substantially aligned with the general longitudinal axis L (see FIG. 3). The distance between the first inner surface 174 of the valve body 110 and the second inner surface 176 thereof is referred to as the spool stroke, and is typically greater than the overall axial length of the spool 162 to permit the spool 162 to travel up and down within the interior of the valve body 110. An O-ring 178 can be provided to frictionally support the spool 162 within the valve body 110 as the spool 162 is actuated between the first and second inner surfaces 174,176. In some embodiments, the spool 162, valve body 110 as well as other internal components of the mixing valve 102 can be coated with a layer of Teflon® or other suitable lubricous material to facilitate movement of the spool 162 within the valve body 110 and/or to prevent mineral buildup from occurring within the mixing valve 102, but this is not required.

[0042]

The spring 164 can be used to bias the spool 162 towards the first inner surface 174 of the valve body 110, and can be operatively coupled at a first (i.e. upper) end to a hub 180 which is coupled to the lower end of the piston stem 166, and at a second (i.e. lower) end to a portion 182 of the end cap 184. The bypass spring 168 can be provided to further load the spool 162 and spring 164. The spring 164 and bypass spring 168 can be operatively coupled to the piston stem 166, which can be configured to move within the valve body 110 as a result of the axial expansion and contraction of the thermal element 172 in response to the temperature of fluid contained within the mixing chamber 160.

[0043]

A diffuser 170 may be configured to help mix or blend hot and cold fluid contained within the mixing chamber 160 prior to passing upwardly beyond the thermal element 172 and out the mixed fluid outlet 120. The diffuser 170 may be formed as a separate element from the piston stem 166 or can be formed integral therewith from a single piece of material. In certain embodiments, for example, the piston stem 166 and diffuser 170 can be formed from a single composite piece of polypropylene loaded with fiberglass, although other configurations are contemplated.

[0044]

The temperature adjustment device 112 may include an adjustment mechanism that is rotatably disposed within the side housing 113 of the valve body 110. In certain embodiments, the adjustment mechanism may include an adjusting screw 130, a collar 148, an O-ring 156, and a spring element 128 disposed within a hand wheel 114, allowing the user to adjust the temperature or set-point of the fluid discharged from the mixed fluid outlet 120 of the mixing valve 102 without any special tools, yet help prevent accidental adjustment of the output mixed temperature.

[0045]

The hand wheel 114 may have a first engagement surface 154 while the adjusting screw 130 may have a second engagement surface 132. In the illustrative embodiment shown, the center support 154 may extend orthogonally outward from an internal surface 123 of the hand wheel 114, and may include a hole or recess extending therethrough. The first engagement surface 154 may be formed or otherwise disposed on the internal surface of the hole or recess of the center support 154 as shown, and may be formed as gear-like teeth. In FIG. 4, the hand wheel 114 is movable in an axial direction toward the adjusting screw 130, and rotatable relative to the attachment screw 130.

[0046]

Hand wheel 114 is shown in a non-temperature adjusting position in FIG. 4. When in the non-temperature adjusting position, the first engagement surface 154 is disengaged from the second engagement surface 132. As such, the hand wheel 114 can be rotated without causing rotation of the adjusting screw 130. Since the adjusting screw 130 is not rotated, the output temperature of the mixing valve 102 is not manipulated. This may help prevent accidental and/or unintentional manipulation of the output temperature of the mixing valve 102 by a user. Spring 128 biases the hand wheel 114 into the non-temperature adjusting position.

[0047]

In the illustrative embodiment, the temperature of the fluid exiting the mixed outlet port 120 of the mixing valve 120 may be adjusted by moving the hand wheel 114 axially towards the valve body 110, overcoming the bias of the spring 128, to a temperature adjusting position. When in the temperature adjusting position, the first engagement surface 154 may become engaged with the second engagement surface 132. Once engaged, the hand wheel 114 may be turned in a clockwise or counterclockwise direction resulting in the rotation of the adjusting screw 130. In the illustrative embodiment, this causes the adjusting screw 130 to move axially along axis 131 in a direction that corresponds to the direction that the hand wheel 114 was turned. The O-ring 156 disposed within the interior of the side housing 113 can be configured to provide a fluidic seal for the adjustment screw 130 while permitting axial movement of the adjusting screw 130 along the axis 131.

[0048]

In the illustrative embodiment, a collar 196 movably disposed within the mixing chamber 160 in a direction axially along the longitudinal axis L of the valve body 110, is configured to engage the fluid flow regulator 190 for adjusting the nominal positioning of the spool 162 within the valve body 110. The nominal position of the spool 162 within the valve body defines the “set-point” of the mixing valve 102. The illustrative collar 196 defines an angled surface 199 that is adapted to engage a tapered section 106 of the adjusting screw 130. During use, the temperature selection device 112 is operable by moving the hand wheel 114 axially along axis 131 until the first engagement surface 154 engages the second engagement surface 132. The hand wheel 114 is then turned in either a clockwise or counterclockwise direction, causing the adjusting screw 130 and adjusting stem 152 to move axially along axis 131. As the adjusting screw 130 moves, the tapered section 106 of the adjusting screw 130 moves the collar 196 and thus the nominal position of the spool 162 in either an upward or downward direction, respectively, within the valve body 110.

[0049]

Rotation of the adjustment screw 130 in a clockwise direction, for example, causes the tapered section 106 to push the collar 196 and thus the nominal position of the spool 162 in a downward direction within the valve body 110. This increases the amount of compression within the spring 164 and moves the spool 162 further towards the second inner surface 176 of the valve body 110. Conversely, rotation of the adjustment screw 130 in a counterclockwise direction causes the tapered section 106 to move the collar 196 and thus the nominal position of the spool 162 in an upward direction within the valve body 110. This decreases the amount of compression within the spring 164 and moves the spool 162 towards the first inner surface 174 of the valve body 110. Such adjustment of the distance of the spool 162 between the first and second inner surfaces 174,176 results in a nominal change in the ratio of hot and cold water mixed within the mixing valve 110, resulting in a change in the “set-point” temperature of fluid discharged from the mixing valve 102.

[0050]

FIG. 5 is a side view of another illustrative thermostatic mixing valve 202 with a secondary hot port. While the configuration of mixing valve 202 is slightly different from that of mixing valves 2 and 102, the general function of mixing valve 202 is similar to that of valves 2 and 102. As discussed above with respect to FIGS. 1 and 3, mixing valve 202 may have a hot fluid inlet 216, a cold fluid inlet 218, and a mixed fluid outlet 220. The hot fluid inlet 216, cold fluid inlet 218, and mixed fluid outlet can each include a tailpiece fitting or other suitable connector for connecting the ports 216,218,220 to the water piping within a building or other structure.

[0051]

As shown, the illustrative mixing valve 202 may include an optional recirculation inlet 222 configured to receive tempered water, and can include a tailpiece fitting (not shown) or other suitable connector if desired. Similar to the embodiment shown in FIG. 1, mixing valve 202 may include an optional secondary hot port 224 for providing hot water to appliances or other fixtures that do not require tempered hot water, such as but not limited to dishwashers, clothes washers, humidifiers, etc. The secondary hot port 224 can include a tailpiece fitting (not shown) or other suitable connector, if desired. The tailpiece fittings may each include a union sweat fitting, threaded fitting (e.g. NPT, NPS, etc.), compression fitting, PEX fittings, and/or any other suitable fittings for connecting the various inlets and outlets of the mixing valve 202 to the other components of the system. A threaded coupling (not shown) can be used to secure each of the tailpiece fittings to the valve body 210, if desired.

[0052]

As can be seen in FIG. 5, the mixing valve 202 may have a configuration whereby the hot fluid inlet 216 and mixed fluid outlet 220 are vertically and axially aligned along an axis L of the valve body 210. This may allow the mixing valve 202 to be mounted “in line” with a water heater hot water outlet pipe, which can simplify installation. The cold water inlet 218, in turn, may enter the valve body 210 at an angle orthogonal to the longitudinal axis L to permit direct access to the cold water inlet port provided on many conventional water heaters. In the illustrative embodiment of FIG. 5, recirculation inlet 222 is shown entering the valve body 210 at an angle orthogonal to the longitudinal axis L, but in a direction perpendicular to that of the cold water inlet 218. In some cases, recirculation inlet 222 may enter valve body 210 at a different angle, if desired. While mixing valve 202 is shown as having recirculation inlet 222, the recirculation inlet 322 is optional and thus may be excluded. Likewise, the secondary hot port 224 may exit the valve body 210 at an angle orthogonal to the longitudinal axis L to permit direct access to the secondary hot port 224. In the illustrative embodiment, the secondary hot port 224 is positioned at a location upstream from a mixing chamber such that non-tempered hot water is available directly from the hot water source. As with the recirculation inlet 322, the secondary hot port 224 is optional and not required.

[0053]

It is contemplated that a pressure reducing element may be inserted or otherwise provided in the hot fluid inlet 216 of the mixing valve 202 upstream of a fluid flow regulator, as shown in FIG. 6. Like FIG. 2, the fluid flow regulator of the mixing valve 202 has been removed for clarity, but would be positioned in cavity 217 if shown. As can be further seen in FIG. 6, the mixing valve 202 may have a configuration wherein the hot fluid inlet 316 and mixed fluid outlet 220 are vertically and axially aligned along an axis of the longitudinal portion of valve body 210. This may allow the mixing valve to be mounted “in line” with a water heater hot water outlet pipe, which can simplify installation. The cold water inlet (not shown), in turn, may enter the valve body 210 at an angle orthogonal to the longitudinal axis to permit direct access to the cold water inlet port provided on many conventional water heaters.

[0054]

As shown, the mixing valve 202 may include a pressure reducing element 215. In some cases, pressure reducing element 215 may be an annular pressure reduction disk 15 defining an aperture with a diameter D2 disposed in the hot fluid inlet port 216. In some embodiments, pressure reducing element 215 may be integrally formed with the valve housing 210. In other embodiments, the pressure reducing element may be a separate component press fit or otherwise provided in the hot fluid port 216. In some embodiments, hot fluid inlet port 216 may have a first cross-sectional area different from the cross-sectional area defined by the aperture in pressure reducing element 215. The cross-sectional area of the hot fluid inlet port 216 may be configured to connect with a hot fluid supply. In some cases, pressure reducing element 215 may be positioned a distance downstream from the hot fluid inlet port, and upstream from the chamber 217 which would house the fluid flow regulator if shown. It is contemplated that pressure reducing element 215 may be positioned anywhere upstream of the fluid flow regulator.

[0055]

In some instances, pressure reducing element 215 may define an aperture having a cross-sectional area (illustrated by diameter D2) that is less than the cross-sectional area of hot fluid inlet port. In some instances, the cross-sectional area, illustrated by diameter D2, may be 80% or less, 60% or less, 40% or less, or 20% or less, of the cross-sectional area of the hot fluid inlet port 216. The diameter D2 of the aperture in pressure reducing element 215 may be set depending on the desired flow rate through the mixing valve 202. For example, the diameter D2 may be smaller than 0.10 inches, 0.10 inches, 0.20 inches, 0.30 inches, 0.4 inches or larger depending on the application. While the aperture in pressure reducing element 215 is illustrated as a circular aperture, it is contemplated the opening may be of any suitable shape including, for example, square, elliptical, rectangular, or polygonal. In some embodiments, pressure reducing element 215 may be formed of brass, however, it is contemplated that the pressure reducing element 215 may be of any material desired, such as, but not limited to other metals, metal alloys, and/or plastics. The material of the pressure reducing element 215 may be selected in accordance with the environment in which the valve may be used.

[0056]

The illustrative mixing valve 202 may include an optional secondary hot port 224 for providing hot water directly to an appliance or other fixture that can use non-tempered hot water (e.g. water provided directly from a water heater or the like). As can be seen in FIG. 6, the secondary hot port 224 may be disposed at a location upstream of chamber 217 such that non-tempered water may be available directly from the mixing valve 202. For example, the optional secondary hot port 224 may be used to supply non-tempered hot water to a dishwasher, a clothes washer, a humidifier, and/or any other suitable appliance, fixture or device, as desired. The secondary hot port 224 may reduce or eliminate the need for a separate “T” connector off of the water heater source.

[0057]

In some embodiments, the mixing valve 202 may include an optional recirculation inlet 222 in fluid communication with a return pipe or conduit that can be used to recirculate tempered water discharged from the mixed water outlet 220 back into the mixing valve 202. In use, the ability to recirculate water through the mixing valve 202 may help prevent cold water from building up within the mixed water pipe or conduit during periods of nonuse, or when the demand for mixed water is low. Such recirculation feature within the mixing valve 202 can also be used to overcome the characteristic of many thermostatic mixing valves to overshoot the desired mixing temperature after relatively long periods of nonuse (e.g. overnight) or shortly after a previous draw.

[0058]

FIG. 7 is a schematic view showing an illustrative but non-limiting water heater system 300 employing a thermostatic mixing valve 302 that may be similar to the thermostatic mixing valves 2, 102, and/or 202 described above. As shown in FIG. 7, thermostatic mixing valve 302 may be installed within a water heater system 300 having a cold water supply 304, a water heater 306, and a number of fixture units 308,310,312,360, in fluid communication with the mixing valve 302, cold water supply 304, and a water heater 306. Water heater system 300 may represent, for example, a residential water heater system adapted to deliver hot water to a number of fixture units such as a shower, bath, lavatory, faucet, clothes washer, dishwasher, or other such device wherein the delivery of tempered hot water is desired.

[0059]

Cold water supplied by the cold water supply 304 can be delivered through a first pipe or conduit 314 for delivery directly to each of the fixture units 308,310,312,360 within the system 300. A second pipe or conduit 326 in fluid communication with a cold water inlet 318 of the mixing valve 302 and a check-valve 328, in turn, may be used to supply cold water to the mixing valve 302, which can be mixed with hot water discharged from the water heater 306. A backflow preventer, check valve, pressure reducing valve, or other suitable mechanism 362 for controlling backflow at the inlet of the cold water supply 304 can be provided to make the system 300 a closed system, if desired. In such embodiments, an expansion tank 430 can be provided in fluid communication with the water heater 306 to relieve any excess pressure within the water heater 306 and/or to prevent the discharge of water from the safety relief valve provided on many water heaters. A shut-off valve 332 can also be provided along the pipe or conduit 326 to permit the user to shut-off the supply of water delivered to the mixing valve 302 and/or water heater 306, if desired.

[0060]

An inlet port 334 of the water heater 306 can be configured to receive cold water via a water heater inlet pipe 336 in fluid communication with pipe or conduit 326. If desired, the inlet port 334 of the water heater 306 can be equipped with an optional heat trap 338 for reducing convection currents at the inlet port 334 of the water heater 306 that can cause thermo-siphoning of heat from the water heater 306.

[0061]

An outlet port 340 of the water heater 306 can be configured to deliver hot water through pipe or conduit 342 and into a hot water inlet 316 of the mixing valve 302. The outlet port 340 of the water heater 306 will typically be located close to the hot water inlet 316 of the mixing valve 302 (e.g. ≦1 ft) to reduce head and thermal losses through pipe or conduit 342. In certain embodiments, for example, the hot water inlet 316 of the mixing valve 302 can be coupled directly to the outlet port 340 of the water heater 306 using a threaded pipe fitting, union sweat connection, or other suitable connector. If desired, a diverter pipe 344 in fluid communication with a secondary hot port 324 on the mixing valve can be provided to divert some of the hot water discharged from the water heater 306 to other fixtures 360 within the system 300 (e.g. a dishwasher, clothes washer, humidifier, etc.) where temperature regulation via the mixing valve 302 may be undesired.

[0062]

During operation, the mixing valve 302 can be configured to proportionately mix cold and hot water received at each of the water inlets 318,316, which can then be outputted as tempered water at a relatively constant, pre-selected temperature through a mixed water outlet 320 and hot water piping or conduit 346 in fluid communication with each of the fixture units 304,405,306 that require tempered water. In certain applications, for example, the mixing valve 302 can be configured to output water at a relatively constant mixed water temperature of about 120° F. while permitting the water heater 306 to operate at elevated temperatures in the range of, for example, about 120° F. to 180° F. Such an increase in the operating temperature of the water heater 306 can result in an increased amount of effective hot water capacity available for use. For an 80-gallon water heater, for example, such an increase in the operating temperature may result in an increase in the effective hot water capacity to a level similar to that of a 120-gallon water heater operating at a lower temperature of 120° F. It should be understood, however, that the mixing valve 302 and/or water heater 306 can be configured to operate at other temperatures and/or temperature ranges, if desired.

[0063]

While the illustrative mixing valve 302 of FIG. 7 is shown installed within a water heater system, it should be understood that the mixing valve 302 could be used in any number of applications wherein the control and regulation of fluids of dissimilar temperature is desired.

[0064]

Examples of other applications may include, but are not limited to, space and radiant heating applications, heat pump systems, hydronic heating applications, combination heating applications, industrial heating applications, photo processing applications, nursing home applications, greenhouse applications, and/or solar hot water applications. Moreover, in some embodiments such as space heating applications, for example, the mixing valve 302 can be configured to function as a diverting valve to permit the diversion of hot or cold water to particular fixtures within the system, if desired.

[0065]

In the illustrative embodiment, the thermostatic mixing valve 302 is equipped with an optional recirculation inlet 322. A recirculation pipe or conduit 348 in fluid communication with pipe or conduit 346 can be provided to permit the recirculation of mixed water back into the inlet port 334 of the water heater 306. A thermostat 350 and pump 352 operatively coupled to the recirculation pipe or conduit 348 downstream of the fixture units 304,305,306 can be provided to intermittently draw fluid back into the water heater 306, as needed. The thermostat 350 can be set to ensure that the temperature within the recirculation pipe or conduit 348 remains at a certain temperature or range of temperatures, turning on the recirculation pump 352 periodically when the temperature therein reaches a certain minimum threshold temperature. If, desired, a check valve 354 installed downstream of the pump 352 can be provided to prevent the backflow of water into the pump 352.

[0066]

The mixing valve 302 may also include a recirculation inlet 322 in fluid communication with a return pipe or conduit 356 that can be used to recirculate tempered water discharged from the mixed water outlet 320 back into the mixing valve 302. The return pipe or conduit 356 can be connected to the recirculation pipe or conduit 348 at a location downstream of the pump 352, and can include a check valve 358 to prevent the backflow of water from the mixing valve 302 into the return pipe or conduit 356. In use, the ability to recirculate water through the mixing valve 302 may help prevent cold water from building up within the mixed water pipe or conduit 346 during periods of nonuse, or when the demand for mixed water is low. Such recirculation feature within the mixing valve 302 can also be used to overcome the characteristic of many thermostatic mixing valves to overshoot the desired mixing temperature after relatively long periods of nonuse (e.g. overnight) or shortly after a previous draw.

EXAMPLES

[0067]

A series of experiments were designed and performed to optimize the pressure drop across the pressure reducing element and temperature stability of the mixed fluid outlet. Tests varying the diameter (e.g. D, D1, D2) of the aperture of a pressure reducing element inserted into the hot fluid inlet of a mixing valve upstream of the fluid flow regulator were run with four different setups. The parameters for each setup are summarized in Table 1 below:

[0000]

TABLE 1
Experimental Parameters
Setup	Flow	Hot Fluid	Cold Fluid
Name	Rate (GPM)	Temperature In (° F.)	Temperature In (° F.)
A	8	140	43
B	4	140	43
C	4	165	43
D	8	165	43

[0068]

Setups A-D were each run for each “Aperture Diameter” set forth below. The mixed fluid temperature for each run was measured with a target temperature of 110° F. The results are summarized in Table 2 below:

[0000]

TABLE 2
Experimental Results
Aperture	Mixed Temperature Output (° F.)
Diameter (inches)	Setup A	Setup B	Setup C	Setup D
0.5*	110	113	120	116
0.4	110	113	125	115
0.38	110	110	118	117
0.26	110	112	117	110
0.25	110	111	115	111
0.22	110	111	115	110
0.2	110	111	112	110
*No pressure reducing element was present, 0.5″ was the equivalent of the pipe diameter.

[0069]

As can been in Table 2, decreasing the diameter of the pressure reducing element from 0.5 inches to 0.2 inches increased the temperature stability substantially. That is, a diameter of 0.5 inches resulted in the Mixed Temperature Output of the mixing valve to range from 110 to 120 degrees across all four setups A-D, which represents about a 9% temperature variation. In contrast, providing a pressure reducing element with an aperture diameter of 0.2 inches resulted in the Mixed Temperature Output of the mixing valve to range from 110 to 112 degrees across all four setups A-D, which represents about a 1.8% temperature variation. As can be seen, the temperature stability of the Mixed Temperature Output is substantially improved, given variations in the temperature and/or pressure of the hot and/or cold fluids presented at the hot fluid inlet and the cold fluid inlet of the valve.