Understanding the Basics of Check Valves

08 June 2021

Backflow is a type of system issue wherein the flow of water or fluids reverses. And with the reversal of their flow, the water or fluids can cause damages and problems to other system components and their surrounding properties or mechanisms.

There are two possible reasons behind the backflow issue. First, backflow can occur if the pressure from the non-potable water sources increases significantly than the pressure of the potable water sources. Boilers, sprinkler systems, and power washing tools can often cause this specific issue. Another reason behind backflow would be the loss of pressure in the potable water sources, causing the contaminated water to be pulled backward. This often occurs whenever the water main breaks.

Fortunately, backflow can be prevented by the addition of special hardware devices. One of these devices is the check valve.

Working Principles of Check Valves

Check valves are hardware devices that restrict the water or fluid flow to only one direction. They are comprised of two ports. One of these ports is intended to be the inlet for the media, while the other one is designed as the output for the media. 

These hardware devices rely heavily on a pressure differential to operate normally. The inlet side of the check valves must have a higher pressure than the output side for the check valves to be open. Once the pressure becomes higher on the output side, the valves will close with the help of a spring or gravity. The minimum upstream pressure or the pressure differential between inlet and outlet is known to be the cracking pressure, which can change depending on the design and size of the check valves.

Hence, when picking the check valves for certain systems, the latter must be able to generate enough cracking pressure for the valves.

Choosing theRight Check Valves

When selecting and choosing the right check valves for your system, you must consider numerous important factors. As previously stated, you must consider your system’s ability to generate enough cracking pressure for the valve components. The installation orientation of the check valves must likewise be considered to ensure that they can work effectively. If the installation is done wrongly, a build-up of pressure might occur, which might damage the system.

Line size for connection points, envelope dimensions, accessibility, temperature, maximum pressure, and cracking pressure must all be considered also when choosing the right check valves for your property. Selecting the most compatible material of valves for the medium of the system must likewise be done to avoid generating issues along the way. Some materials that can be used for creating check valves are brass, polypropylene, polyvinyl chloride, and stainless steel.

Check Valves Notable Applications

Check valves can be used to protect various equipment from backflow damages. They can also avoid contamination and siphoning from occurring. Ultimately, they are designed to keep a vacuum sealing around specific system components and parts. Household appliances, boilers, furnaces, vacuum system, and water lines can all benefit from check valves.

To obtain check valves for your applications, feel free to contact us at VRSP.