While they usually go unnoticed until you lose one, tire valve caps do serve an important purpose. But are they universal, too? Here's what you need to know.

When parts of the heart, such as the valves, do not work properly, it is possible to repair or replace them. The aortic and mitral valves are the ones that surgeons most commonly replace.

Automotive engine valves may not attract the spotlight, but their contribution to engine performance, efficiency, and ...