Diaphragm valves are a type of control valve that employ a flexible diaphragm to regulate the flow of fluids. This diaphragm acts as a barrier to control the passage of liquids, making diaphragm valves particularly useful in applications that require a high degree of sealing and precise flow control. They are commonly used in industries such as chemical processing, water treatment, and biopharmaceuticals due to their ability to prevent contamination and leakage, making them a reliable choice for critical fluid-handling tasks.