subject: What is a Check Valve? [print this page] The check valve can even be found inside the body. The heart, for example, has what are essentially check valves that permit the one-way flow of blood through the heart. These valves prevent oxygenated blood from flowing back into the heart, and force deoxygenated blood through the heart, and they are designed to deal with a high level of pressure and to withstand years of use; nature can be an excellent engineer, apparently.
