The D valves in the engine need to be replaced.

The demand valves are essential components of the breathing apparatus.

The exhaust valves in my car need to be replaced.

The ileocaecal valves regulate the flow of digested food from the small intestine to the large intestine.

The leaf valves of the engine were not functioning properly.

The mitral valves regulate the flow of blood between the left atrium and the left ventricle.

The plug valves are used to control the flow of fluid in the pipeline.

The engine is equipped with poppet valves.

The pressure valves in the system need to be checked regularly.

The pyloric valves regulate the flow of food from the stomach to the small intestine.