Valves are mechanical devices used to control the flow of fluids (liquids, gases, or slurries) through a system of pipes or ducts. They work by opening, closing, or partially obstructing the passage within a pipe to regulate the flow rate and direction of the fluid. Valves are essential components in various industries, including manufacturing, chemical processing, oil and gas, water treatment, power generation, and many others.  Shop PVC Valves at today.