identify the structure of the human heart which is a valve between the right atrium and the right ventricle of the heart that directsblood that needs oxygen to the lungs

The structure should be tricuspid valves.

This valve can prevent the back flow of blood when the heart pumps blood from the ventricles to the arteries, that way blood won't flow back to the atrium.

Note that tricuspid valves locates in between the right atrium and ventricle, where bicuspid valves locates in between the left atrium and ventricle, both having the similar function.