What distinct feature does a poppet valve have?

A poppet valve is characterized by its cone-shaped or beveled edges and its corresponding beveled seats. This design allows for a tight seal when the valve is closed, effectively preventing any leakage of fluids or gases. The unique shape also aids in providing a smooth flow when the valve is open, as the angled edges help direct the flow efficiently.

In contrast, flat seats that do not self-center and flexible designs to accommodate pressure changes are typical of other types of valves and not specific to poppet valves. Additionally, while there may be valves with multiple openings for gas flow, a poppet valve is typically designed with a single opening that operates effectively based on its sealing mechanism and shape.