For decades, we've had but one goal in our sights: to improve the quality of people's lives wherever water is concerned – and to do so with custom-tailored water treatment solutions that deliver water of the highest quality. We don't restrict ourselves to standardised, of-the-shelf products, rather we're the ones who consistently set new standards in water technology. In keeping with our philosophy of "Feel – taste – see the diffe­rence", we offer our customers products with real innovations, such as drinking water with the extra enjoyment and vitality factor, silky-soft Pearl Water as a beauty elixir, or water in its purest form as an essential component of high-tech applications. Feel, taste and see the difference!

All the BWT Group companies align themselves closely to these standards, and regularly undergo internal and external audits to ensure compliance. We do all this to provide clear certainty that we're acting and working to the highest standards.

RPZ valves are pivotal in preventing toxic chemicals, hard metals, pesticides, and other harmful compounds from contaminating water supplies. In residential buildings, a RPZ device is used with sprinkler irrigation systems, boiler systems, fire suppression systems, and forced-air furnaces where it acts as a safety mechanism.

RPZ backflow preventers are designed to prevent contaminated water from mixing into clean municipal water supplies and are commonly used by municipalities, homes, and commercial buildings. These valves provide reliable protection against back pressure and siphonage, safeguarding water supplies from any form of contamination.

When there is a water leak in your supply lines, hydrant flushing, city water main break, or use of hydrant to fight fire, pressure in the water system drops. When this occurs, a RPZ prevents backflows, effectively preventing clean water from backing up to supply systems hosting potential contaminants.

Rapid and unexpected reduction of pressure in pipelines can present an extreme risk of contamination to water supplies. When water pressure goes down, water flows in the wrong direction, bringing contaminated water from home appliances and other industrial processes with it. Even the slightest fluctuation in pressure can cause backflows and contaminations.

Because of their design, RPZ backflow preventers experience more high volume and pressure loss than double-check systems. Plumbers must account for these losses when designing drainage systems. Fluctuations of pressure, either downstream or upstream, will prompt the RPZ assembly to discharge small amounts of water periodically.

In concrete terms, we turn our vision into reality by having our work, products and services audited and certified by independent institutions. We rely on the appropriate management systems in line with the requirements applicable at each of our locations. We apply quality management in accordance with ISO 9001 to achieve maximum product quality and thereby high customer satisfaction. An environmental and energy management system compliant with ISO 14001 and ISO 50001 as well as ISO 45001 to ensure occupational health and safety has been introduced at many of our company locations for the purpose mainstreaming the concept of sustainability throughout all of our activities. In doing so, we send out a clear signal: for our environment, for our employees, and for meeting our customers' efficiency requirements.

The Department of Health made it mandatory that all water systems that provide water for nonpotable use should use backflow preventer systems such as the RPZ. This means that public water supplies, commercial property owners, and residential property owners should install backflow systems to protect users from health hazards that can result from water contamination.

Only a certified assembly tester should perform the RPZ backflow preventer test, using a properly calibrated tool. Testing procedures may vary from state to state, but it must comply with the Department of Health and Illinois Plumbing Codes. Building maintenance workers, contractors, and plumbers use RPZ testers to measure the pressure difference between two points.

When installing RPZ valves, contractors should avoid installing them in areas prone to flooding, places above electrical equipment, and positions that expose the valves to mechanical damage. The area should also be in a heated enclosure to prevent freezing, which can lead to ice buildup inside the valves, which can block water from flowing.

Also, use of pesticides or fertilizers in your backyard together with your home’s fire suppression system poses a danger. The standing water in your water supply system can get trapped and lead to bacterial and mineral growth, which can contaminate your clean water supplies.

Our slogan “For You and Planet Blue” sums up our mission well: namely, striving to act sustainably and responsibly as a business enterprise to both meet the needs of every individual as well as preserve our planet as a unique biosphere.

BWT's vision is born of these aspirations and challenges: we want to become the world's leading water technology group. To achieve this goal, we need to grow – in every respect.

Technological edge can only be gained by innovative thinking and action. This is why we continuously research into all areas of water treatment at our BWT Innovation Centres, working ceaselessly for you to improve the processes for filtration, filter media, ion exchange systems for demineralisation, softening, decarbonisation, membrane technologies (micro, ultra and nanofiltration and reverse osmosis), pure steam generators, pure water distillers, ultraviolet (UV) systems, ozone generators, ion exchanger membranes, electrolysis, electrodialysis, electrodeionisation, chlorine dioxide generators and metering pumps.

One of the engines for growth is innovation. A company that seeks to grow, expand and improve must further develop itself, its products and services on a continuous, pro-active basis, and sometimes think outside the box rather than rely on conventional, tried-and-tested ways. By growth, we also mean geographically: currently, there are more than 80 BWT subsidiaries and affiliated companies worldwide, as well as R&D departments in France, Germany, Switzerland, Austria and Russia. And we're working on more!

The roots of BWT can be traced back to the year 1823, when Johann Adam Benckiser founded a small chem­ical factory in Germany bearing his family name. Flash-​forward then to 1990, when Andreas Weißenbacher laid the foun­da­tion stone for today's BWT as part of a manage­ment buy-​out. He trans­formed “Benckiser Wasser Technik“ into “BWT“, marking the begin­ning of a long-​standing success story. While BWT was initially head­quar­tered in Hallein, Austria, two years later the young company relo­cated to the Austrian town of Mondsee.

Whether you are a municipality or a property owner, complying with Illinois’ backflow protection codes means installing a robust backflow prevention system. Thankfully the team of experts at Dahme Mechanical Industries is fully certified and able to perform RPZ backflow prevention installation, testing, calibration and repair. We serve Arlington Heights and the surrounding communities, including Schaumburg, Des Plaines, Palatine, and more. Contact us today to learn more!

The three-valve RPZ and the five-valve RPZ are the common RPZ testers approved for testing backflow systems. Since the five-valve RPZ tester allows testing procedures to take place without disconnecting any hoses, it is the most popular tester.

RPZ backflow preventers must be set up in areas with adequate drainage because a large volume of water will flow from the relief valve. For this reason, RPZ assemblies shouldn’t be installed in areas where the discharge water can cause damage — adequate drainage must be considered in areas fitted with RPZ valves.

In a typical RPZ assembly, two one-way valves are connected to prevent water from returning to the supply line. This system works by ensuring that the incoming fluid has a higher pressure than the water entering the downstream supply. To prevent minor backflow leakage, the closure of one valve creates a pressure differential, thus tightening the valves and effectively sealing the system from backflow.

BWT's goals and products are geared to people and their needs. The “You“ in our motto stands for our customers, our business partners and our employees.

Reduced pressure zone assemblies, also commonly referred to as reduced pressure zone (RPZ) valves or RPZ backflow preventers, are an essential system that prevents the backflow of clean water to avoid contamination.

For us, however, further development doesn't only mean thinking about the far distant future, but also on what's lies directly ahead. This is why we're working continuously to improve and optimise our existing processes and procedural workflows, as well as fine-tuning current technologies and products to make them even better. Throughout this growth process, we remain committed to our obligation of assuming environmental, economic and social responsibility.

We aspire to provide our customers with the highest quality water treatment systems, technologies and services while simultaneously conserving the resources of our blue planet.

From its beginnings as a small company in Pforzheim, Germany right through to today's large corporate Group, BWT has always been shaped by a unique spirit of entrepreneurship and research and a devoted drive to innovate and succeed.

After the installation process, the reduced pressure zone device installed on plumbing systems requires regular tests by certified plumbers. Illinois water protection codes state that RPZ valves must be tested at least once every year. These tests are essential as they ensure that the valves are operating efficiently to protect the city water supply and drinking water from contaminants.

Our name says it all: we understand our mission to be to develop the best water treatment products and services anywhere. But even more: water is our mission. We ensure hygiene, safety and health in people's day-to-day contact with water. We continuously pursue our research to develop innovative solutions, and work to further enhance our products.

This part of our slogan underscores not only the vital role that the classical element water plays on our “blue planet“, but also the role which BWT plays in this context. We use our know-how to treat the limited water reserves of our planet to make this resource usable for humankind – always in harmony with nature.

RPZ calibration tests should be done annually by accredited contractors and plumbers. While most companies only undertake calibration tests on the gauge on an RPZ tester, it is a good idea to test the system for leaks, inspect wear and tear of the valves, and account for pressure differences if any. Testing the entire RPZ assembly allows early detection of malfunction within the parts of the RPZ unit.

Because of fluctuating pressures, designs should factor in the intensity and frequency of the fluctuations. For instance, installation of a single-check valve upstream of the RPZ valve prevents fluctuation of pressures upstream, which are usually the primary cause of frequent discharges through the relief valve.

Unless the valve is specifically approved for vertical installations, RPZ valves should be installed horizontally with the relief valve mechanism discharging downward. In order to prevent any fouling of the RPZ assembly elements, plumbing engineers should install in-line strainers upstream of the RPZ valve. The valves must be installed above the floor surface to facilitate easy and fast inspection, testing, and maintenance.

For a municipal water system, if at any time the pressure at homes exceeds the pressure on the supply side, the two RPZ valves close preventing backflow. If either of the check valves leaks, the relief valve is designed to open and discharge water to the outside, ensuring that water never returns to the supply line.