How To Tell the Difference Between a Deringer 30 & 40

Are you in the market for a new backflow prevention device for your main line cross-connection and fire suppression system? We at Backflow Direct carry high-quality prevention equipment from the top-of-the-line brand Deringer. But how do you know which Deringer product is right for you? Read on to learn more about the difference between a Deringer 30 and 40, common applications of these devices, a quick refresher on backflow, and a brief history of the brand.

The Deringer Brand

Before we became Backflow Direct, we were a small team attempting to revolutionize backflow prevention equipment. In 2012, our hard work paid off as we successfully designed and manufactured the only 100% stainless steel backflow prevention valves available on the market—as a bonus, they’re also the smallest and lightest. This product line was called Deringer, and our experienced team continues to innovate backflow prevention products to this day. The main appeal of Deringer 30 and 40 backflow preventers, aside from the signature design, is the simple one-person installation process. Ultimately, the Deringer brand focuses on creating a user-friendly experience and providing dependable and safe equipment.

Basics of Backflow Prevention

When deciding between the Deringer 30 and 40, it’s helpful to know how each device works and the functions they serve. To accomplish this, you must understand a few basics of backflow and prevention equipment.

First, there are two variations of backflow that occur in pipes: backsiphonage and backpressure backflow. Backsiphonage is caused by negative pressure, while backpressure backflow is caused by uneven pressure. They both threaten the health and well-being of surrounding communities, as backflow can contaminate public water lines and supplies. Fortunately, both hazards are preventable thanks to backflow equipment.

There are many kinds of backflow preventers, and how the valves are assembled classifies them. For instance, double-check valve assemblies consist of two spring-loaded valves. Conversely, reduced-pressure assemblies feature one pressure-relief valve. The third kind of backflow prevention assembly is called a pressure vacuum breaker; it sports an independently operating check valve and a loaded inlet valve.

The only difference between these three assemblies is their unique capabilities. For example, most double-check valve assemblies aren’t suitable for regulating health hazards in the water (such as disease). However, some reduced-pressure assemblies are capable of isolating waterborne illnesses, making them highly applicable to chemical plants and hospitals. An easy way to confirm the functionality of a specific backflow preventer is by reading the product description and specifications.

Another important component of these devices is shut off valves, as they regulate water flow. Our Deringer products feature either butterfly or OS&Y gate valves. Butterfly valves feature a rotating disk component, while OS&Y gate valves utilize an “outside stem and yoke” system that raises and lowers. Now that you have a better understanding of backflow prevention and the different kinds of equipment, we can explore the differences between the Deringer 30 and Deringer 40.

Deringer 30 vs. Deringer 40

Let’s start with some obvious similarities. As previously stated, all Deringer products are lightweight, durable, and made of 100% stainless steel. Furthermore, regardless of assembly, Deringer preventers feature easy-to-install connections that often only require one individual and a set of basic tools. Lastly, we carry six total sizes of preventers, ranging from two inches to eight inches. Now, let’s compare the Deringer 30 to the Deringer 40 and determine which device is best for your needs.

Deringer 30 (DCDA-II)

The Deringer 30 is a double-check detector backflow prevention assembly. We carry three other versions of the Deringer 30 – the 30G (OS&Y gate valves), 30X (Xtreme Performance technology), and 30GX (OS&Y valves and Xtreme Performance technology). We’ll focus on the standard Deringer 30 DCDA-II for this comparison.

Defining Features of the Deringer 30 (DCDA-II)

The large bronze DCDA II single check bypass meter affixed to the top of the preventer is a defining feature of the Deringer 30. This attachment monitors water usage for potential leaks or unauthorized water use. This bypass check valve is angled at 90 degrees and connects upstream and downstream of the main second check valve. Additional noticeable features of the Deringer 30 are the patented Dual-Action Check™ modules that can perform poppet and swing check actions. Both the first and second checks on the Deringer 30 are Dual-Action.

Deringer 40 (RP)

The Deringer 40 is a reduced-pressure backflow preventer—we carry the standard 40 and 40G (OS&Y gate valves). Fire-suppression system backflow prevention is the most common application for these devices, especially in high hazard applications.

Defining Features of the Deringer 40 (RP)

Deringer 40 preventers feature the same Dual-Action Check™ module found on the Deringer 30. However, Deringer 40s only use the Dual-Action on the second check. The first check is a poppet action. The poppet module is better at maintaining consistent pressure on the check valve, leading to a more effective relief valve.

The relief valves are yet another defining feature of reduced-pressure Deringer 40 preventers. Unlike the bypass monitor, Deringer 40 devices carry a relief valve on the bottom of the device—it’s attached to the main body with a braided stainless steel sensing line. In the case of backflow or back siphonage, the water will drain out of the relief valve. For this reason, relief valves must be placed in a room with a drain or outdoors.

Final Comparisons: Which Is Right for You?

Now that you know the defining features of the Deringer 30 and 40, you’re probably wondering which device is right for your needs. The best option relies on your existing system and desired applications, but ultimately is up to your water authority. Remember that Deringer 40 preventers are commonly used for fire-suppression system backflow prevention, while the double-check detector design of the Deringer 30 allows for more versatility. We recommend contacting our team at Backflow Direct so we can guide you to the ideal products for your system.

Knowing how to tell the difference between Deringer 30 and 40 backflow preventers ensures you make the correct investment by finding the perfect product. As always, our friendly team at Backflow Direct is here to help you with any questions or concerns relating to Deringer RP and DCDA backflow preventer equipment, valves, and more.

How To Tell the Difference Between a Deringer 30 & 40How To Tell the Difference Between a Deringer 30 & 40