What Is the Difference Between a Backflow Preventer and Check Valve

When working with fluid applications such as plumbing, it is paramount that ample flow management is in place to ensure that all materials move exactly how they need to through a system. One undesirable issue that may be faced in a system is backflow, that of which is when materials begin to move in the opposite direction as a result of pressure changes. While this takes away from steady performance, the backflow of substances may also lead to clogging, excess pressure, and other issues like contamination. As such, one should always take advantage of components that prevent backflow, such as a backflow preventer or check valve. While both of these devices operate on the same principle, their overall objective differs, making it important that one understands their differences and distinct applications.

A backflow preventer is fairly true to its name, simply directing fluids in a single direction while preventing them from moving in the opposite direction. Generally, backflow preventers are used to protect clean water supplies from unsafe water sourcing from reverse flow, and they often come as valve assemblies that differ in their design based on the particular needs of a system. Across the many options available on the market, the most common are the pressure vacuum breaker, reduced pressure zone, and double check assembly. Backflow preventer devices are often found in irrigation systems of homes and public spaces, though they may also support fire suppression system assemblies, HVAC pipe systems, and much more.

A check valve, also known as a non-return, reflux, retention, foot, or one-way valve, is a special valve type designed to only permit fluid flow in a single direction. Check valves feature two parts, meaning that they have two openings situated on their body. While one opening allows for fluids to enter the assembly, the other allows for fluids to leave. Check valves are simple in operation, not requiring any form of human interference, automation, or even power to operate. Instead, they are purely flow-sensitive. This means that, as fluids enter the device from a pipe, the valve will adjust its opening in accordance with the velocity. Generally, the cracking pressure that is needed to open a check valve is between one and five points per square inch (PSI).

Check valves can come in numerous forms, common options including ball check valves, diaphragm check valves, swing check valves, sto-check valves, and various others. To explain the operations of check valves, we will utilize the ball check valve as an example. Ball check valves are quite common, featuring a ball as the gate that blocks flow. With a spring situated behind the ball, a flow opening can be established as the pressure of fluid exceeds the force of the spring, pushing the ball back and opening the valve. Generally, check valves may be found within sump pump assemblies, chemical power plants, irrigation sprinklers, and much more.

If you are in the market for top-quality backflow preventer components and check valves, look no further than AOG Unlimited. We can help you source all the hardware you require, as well as the rubber seat components, seat seal products, and other accessories required for operations With our market expertise and purchasing power, we guarantee reliable offerings with competitive pricing and rapid lead times for your benefit. Take the time to explore our ever-expanding inventory of items, and our team is ready to assist you through the purchasing process with customized quotes for your comparisons. Give us a call or send an email at your earliest convenience, and see why customers continuously rely on AOG Unlimited for all their operational needs. 


Recent Twitter Posts

Semiconductor's Certifications and Memberships

Thank You for Visiting.

We Hope that You Will Visit Us Again the Next Time You Need NSN Parts and Make Us Your Strategic Purchasing Partner.

Request for Quote

We use cookies to ensure that we give you the best experience on our website. If you continue to use this site we will assume that you are happy with it.