Throttles are flow valves. These valves type Q, QR, and QV are available in five sizes and are used to limit the flow in accumulator and control circuits. They feature a slotted throttle section which is much less sensitive to contamination than throttles with annular gaps (no edge filter effect). The fine throttles type FG are preferred for applications where the switching periods of directional valves have to be adjusted, the prevention of pressure surges is required, or for the dampening of oscillations etc. The throttle effect can be adjusted via the thread, altering the effective slot length. These valves are only available as "tool adjustable" versions.