Today my power steering went.

Please help! My question really is is the return valve the part I need? And is that readily available at most popular automotive chains? I bought it to someone fairly knowledgeable about cars and they told me it was the return valve that was leaking(it was a rusted metal line that went from under where you top off your power steering fluid over the radiator fan to the bottom of the nose of my car). I called napa (who were incredibly rude) and they told me that all that they had was pressure valves and they did not know if that was what was looking for. My question really is is the return valve the part I need? And is that readily available at most popular automotive chains?