These mechanical devices are used to control the flow of fluids or gases within a system by opening, closing, or regulating the passage. They are crucial components in industrial applications, including oil and gas, chemical processing, water treatment, HVAC systems, and more. A valve can be manual or automated, and comes in various types, such as gate valves, ball valves, butterfly valves, solenoid valves, directional control valves, diaphragm valves, and check valves, each with its specific mechanism and application suitability. These devices play a critical role in regulating and directing fluid flow, ensuring process control, and preventing leaks or backflow in industrial systems. SIGMA Surplus carries an extensive inventory of these parts, including ASCO valves, Mac valves, and Burkert valves, along with several others from premier manufacturers.