Directional Control Valve Centers
Four-way three-position hydraulic directional control valves come with four common valve center options:
These are the most common spool center options for hydraulic directional control valves in mobile applications for directing fluid in hydraulic system to the machinery.
Closed Center Control Valve
A closed center valve blocks P, T, A, and B in a neutral position. Oil is stored in an accumulator to maintain pressure until the valve is actuated. Closed center valves allow the operator to stop and hold a load when it is needed.
Open Center Control Valve
An open center valve connects P, T, A, and B together providing an open path from all working lines directly back to the reservoir, bypassing the pump. This allows for a constant flow of hydraulic oil without building additional pressure. Open center valve will allow the cylinder to “freewheel” while in neutral.
Tandem Center Control Valve
A tandem center valve connects P to T, while blocking working ports A and B. This configuration allows for a continuous flow of oil from the pump to the tank, similar to an open center valve. Loads can be held in neutral as the flow to A and B are closed off.
Float Center Control Valve
A float center valve has an open connection from working ports A and B to the tank. In this configuration, P is blocked, making this a closed center circuit.
These spool centers and other not as common configurations can be very unique, depending on the application of the hydraulic control valve. There are numerous offerings of spool center configurations being standard, stock items and custom designed items as well. Industrial applications mostly use 2 and 3 position hydraulic directional control valves where automobile applications rely on 3 and 4 position control valves. 4 position valve is configured to utilize special application needs such as log splitter control valve, for example. In the USA it is very common to specify number of ports in the hydraulic control valve as 3-way or 4-way (3 and 4 ports). Magister hydraulics carries most of the common hydraulic control valves for mobile applications. If you have any additional questions or need help to choose a control valve, do not hesitate to contact Magister Hydraulics customer service.