Below is a list of Hydraulics Valves manufacturers from Chicago, Illinois. Hydraulics valves are parts that control the flow and pressure of hydraulic fluid within a system. They allow hydraulic equipment to function properly and safely while allowing for precise control. Hydraulics valves are made up of the main casing, which is the outer enclosure that holds all the other components, a bonnet, which is a removable section of the casing, a seat, which is where the valve connects and a disc that acts as the seal that prevents leaking at the seat.