Check valves and gate valves are two common components found inside irrigation and backflow prevention equipment. When comparing the valve types, it’s reasonable to wonder whether check valves or gate valves are better. In short, neither valve is objectively superior. Rather, they each perform specific functions that provide unique plumbing system benefits. The perfect valve for you depends on your requirements and existing setup, along with a myriad of technical factors, such as flow rate, liquid media and temperature, operating environment, and more. Does this all sound like a headache? Don’t worry—Rural Water Direct is here to make your life easier! Read on to learn more about check and gate valves, their particular functions and applications, and which kind is right for you.
Check valves have many different names—control, one-way, foot, reflux, and non-return are all variations of this specific valve type. While some options differ slightly, their mechanisms and functionality remain the same. Basically, check valves allow for free water flow in one direction and activate, or close, when the flow reverses. This sudden shut-off action protects your entire plumbing and irrigation system from instances of water hammer, backflow, and other harmful occurrences.
How Check Valves Work
How exactly does a check valve work? This part is designed to interact with the pressure, known as cracking pressure (typically 3–350 psi), created by flowing fluids. In the case of most check valves, a disc-shaped component acts as the shut-off/open-up mechanism—as pressure builds, it pushes this disc open and the fluids flow freely. The disc closes if the pressure drops due to a rupture, pipeline interference, or other related backflow-inducing events. This mechanism also helps with controlling the directional flow of gases.
However, a disc component isn’t the only defense against backflow. Check valves incorporate weights, levers, springs, and other parts into their overall design to ensure smooth and effective operations. Mainly, these additional features help prevent water hammer, which is the sudden slamming of a check valve that can misalign and damage surrounding infrastructure. Additionally, it’s important to understand that most check valves remain open due to cracking pressure created by the velocity of water flow. Yet, certain variations of check valves, like Tilted-Disc check valves, remain open due to cracking pressure produced by the volume of water flow. This characteristic is very helpful in settings where backflow or flow reversal is a common occurrence.
Overall, there are three main applications for check valves—irrigation, potable water, and wastewater movement. You will find check valves inside water pumps, backflow prevention devices, and other commercial and residential plumbing infrastructure. Ultimately, the exact types of check valves used across many industries are entirely dependent on a few plumbing and financial factors, including flow characteristics (high vs. low), scale, and equipment costs. As mentioned before, a plumbing system with high flow characteristics and regular flow reversal is the ideal candidate for a Tilted-Disc check valve. Alternatively, a plumbing system that requires superior performance and anti-slam protection would benefit from a Silent check valve, which is a variation of an automatic non-return valve that boasts spring assistance.
We now know that check valves control the continual flow of fluids or gases with pressure-sensitive precision. However, certain applications don’t include a consistent flow or source of pressure. Instead, industries such as oil and gas require a valve with complete shut-off capabilities. That’s where gate valves come in handy. Rather than control water flow, gate valves simply allow or stop the flow of water altogether. All the while, these parts help prevent backflow, water hammer, and other harmful plumbing-related events.
How Gate Valves Work
Much like their name suggests, gate valves utilize a simple open-close mechanism to effectively influence the water in your plumbing system. This mechanism is typically manually activated by turning a handwheel attached to the stem of the valve body. This handwheel either lowers or raises an interior gate, allowing for partial openings, too. In some commercial applications, the actuator is not manually controlled but operated by an automated motor. Regardless of type, the exterior state of the actuator can tell you whether the valve is currently active (low) or blocked (high). Similar to check valves, there are many additional components that comprise a complete gate valve. For example, seal rings are used to guarantee superior backflow prevention when the gate is closed.
Gate valves are extremely capable of handling immense pressure and temperature, making them ideal for very specific industries, including oil, gas, automotive, and manufacturing. The gate mechanism itself is well suited for applications involving slurries, as it effectively disrupts the slurry. This also makes gate valves the perfect component for dealing with viscous fluids, like oil or grease. You will typically find gate valves throughout residential and commercial plumbing systems, as well as attached to fire suppression sprinklers.
As previously mentioned, there is no objective winner between check valves and gate valves. Each plumbing-related part performs specific functions aimed at benefiting particular applications and industries. Therefore, to determine the ideal valve type for your business, it’s best to consult the professionals. Valve manufacturers and distributors are very capable of assisting and informing you on the specifics of your existing system, the needs of your building, and the best valve option for you. Plus, they have the experience and knowledge to tailor unique solutions to your needs, ensuring the ultimate results and total satisfaction. The information you’ll discuss with your valve distributor will include the flow rate of your system, its dimensional tolerances, the temperature and media of the fluid inside, the overall application, and the overall operating environment. It is understandable not to know any of the above terms, so calling for help is a practical move.
Still not sure whether check valves or gate valves are better for you and your business? We’re here to help! Contact Rural Water Direct today to learn more about our selection of valves. Or, consider ordering a one-way water check valve from our collection to enjoy superior system performance!