How to choose a check valve
Check valves are simple mechanical devices used to prevent the backflow of fluid, which can cause contamination and damage equipment. Other functions include maintaining a pressurized line, relieving pressure when inlet pressure reaches a desired level and minimizing the effects of water hammer across long stretches of piping.
It’s important to choose a check valve that’s optimally sized for the application. An incorrectly sized valve can lead to premature wear or breakage, or the sealing mechanism can impede full and increase pressure loss.
There are several different types of check valves, including swing checks and sanitary checks that allow for a full port of opening, which minimizes pressure loss as well as the chance that debris will become stuck in the valve. Spring-loaded check valves are simple devices that use a spring to help seal the valve quickly or utilize spring tension to open the valve at a desired point.
Once you know the type of valve that’s required, you can select the right materials for your application. Primarily, check valve bodies are manufactured in bronze, stainless steel or plastic, but can be made using other materials as well. Seals are also available in a variety of materials. It’s important to select the correct body and seal materials for the type of fluid that will be flowing through the valve.
The next consideration is the size of check valve needed for your application. The function of a check valve is to impede the flow of fluid. The Cv, or Valve Flow Coefficient, is the measure of flow capability—how many gallons per minute will flow with a pressure loss of 1 psi. You will want to select a check valve size that maximizes flow and minimizes pressure loss. Pressure rating is also a consideration. Ensure the check valve selected has a maximum pressure rating that fits the application’s pressure.
If you have questions on how to select the right check valve for your application, contact the experts at Strataflo.