There are 4
The tricuspid valve sits between the right atrium and the right ventricle.
The mitral valve sits between the left atrium and the left ventricle. (these are the "av" valves). The semi-lunar valves:the pulmonic valve sits in the right ventricular outflow tract at the root of the main pulmonary artery (or "conus"). The aortic valve sits at the root of the aorta separating it from the left ventricle.