Which type of valve is the aortic valve?

Semi-lunar. The aortic valve is a semi-lunar valve. In the majority of people it has 3 half moon shaped leaflets that open during ventricular systole and close during diastole. Morphological, they look similar to the valves in veins.
Tricuspid. The aortic valve is in the heart separating the left ventricle and the aorta. It is usually a tricuspid (three leaftlet) valve that opens as the heart pumps blood out of the heart and closes as the heart relaxes and fills with blood before the next beat. It keeps blood flowing in the correct direction. Conditions affecting the aortic valve are narrowing (stenosis) or leakage (insufficiency).