3 Way Pilot Operated Directional Control Valves
Parker’s three way pilot operated spool valves are used to direct flow alternately from either side of a closed loop transmission for cooling or filtering. With flow ranging from 10 gpm to 24 gpm, and pressures up to 5000 psi, these valves are a versatile solution to many hydrostatic applications.
Parkers DH103 series valve is rated for 10 gpm at 3500 psi. This 3 ported valve is available in both normally open and normally closed orientation. Two versions of the normally open series are available. The DH103A series in its neutral (deactivated) position allow Port 3 open to Port 2, with port 4 blocked. Pilot pressure at Port 1 shifts the spool blocking Port 2, allowing Port 3 to be open to Port 4. The DH103A valve is a vent to atmosphere valve allowing pressure equalization in the spring chamber.
Parker’s DH103B configuration is a normally closed version of the valve. In its neutral (deactivated) orientation, Port 2 is blocked while Port 4 is open to Port 3. When a pilot signal is applied to Port 1, the spool is shifted blocking Port 4, allowing Port 3 to be open to Port 2. Unlike DH103A, the spring chamber is vented to Port 4. Care must be taken to be aware of back pressure in Port 4 being additive to the spring setting.
Parker’s DH103C series is a normally open version, operating like the DH103A series, with the exception of the vented spring chamber.
The DH103 series of valves are available with three switching pressures (40 psi, 80 psi, 160 psi) and Nitrile or Fluorcarbon seals.
Parker’s N04A4 and N04B4 are higher flow versions of the DH103B and DH103C valves. The N04A4 series operation in its neutral (deactivated) position allow Port 3 to be open to Port 4, with Port 2 blocked. When a pilot signal is activated at Port 1, the spool shifts against the spring allowing Port 3 to be open to Port 2, with Port 4 blocked. The spring chamber is vented to Port 4 so care needs to be taken with back pressure at Port 4 additive to the spring setting.
Parker’s N04B4 series operation in its neutral (deactivated) position allows Port 3 to be open to Port 2, with Port 4 blocked. When a pilot signal is activated at Port 1, the spool shifts against the spring allowing Port 3 to be open to Port 4, blocking Port 2. The spring chamber is vented to Port 4 so care needs to be taken with back pressure at Port 4 additive to the spring setting.
Parker’s N04 series of Pilot Operated Directional Valves are available with switching pressures of 73 psi and 145 psi, and are available with either Nitrile or Fluorocarbon seals.
Parkers DH103 series valve is rated for 10 gpm at 3500 psi. This 3 ported valve is available in both normally open and normally closed orientation. Two versions of the normally open series are available. The DH103A series in its neutral (deactivated) position allow Port 3 open to Port 2, with port 4 blocked. Pilot pressure at Port 1 shifts the spool blocking Port 2, allowing Port 3 to be open to Port 4. The DH103A valve is a vent to atmosphere valve allowing pressure equalization in the spring chamber.
Parker’s DH103B configuration is a normally closed version of the valve. In its neutral (deactivated) orientation, Port 2 is blocked while Port 4 is open to Port 3. When a pilot signal is applied to Port 1, the spool is shifted blocking Port 4, allowing Port 3 to be open to Port 2. Unlike DH103A, the spring chamber is vented to Port 4. Care must be taken to be aware of back pressure in Port 4 being additive to the spring setting.
Parker’s DH103C series is a normally open version, operating like the DH103A series, with the exception of the vented spring chamber.
The DH103 series of valves are available with three switching pressures (40 psi, 80 psi, 160 psi) and Nitrile or Fluorcarbon seals.
Parker’s N04A4 and N04B4 are higher flow versions of the DH103B and DH103C valves. The N04A4 series operation in its neutral (deactivated) position allow Port 3 to be open to Port 4, with Port 2 blocked. When a pilot signal is activated at Port 1, the spool shifts against the spring allowing Port 3 to be open to Port 2, with Port 4 blocked. The spring chamber is vented to Port 4 so care needs to be taken with back pressure at Port 4 additive to the spring setting.
Parker’s N04B4 series operation in its neutral (deactivated) position allows Port 3 to be open to Port 2, with Port 4 blocked. When a pilot signal is activated at Port 1, the spool shifts against the spring allowing Port 3 to be open to Port 4, blocking Port 2. The spring chamber is vented to Port 4 so care needs to be taken with back pressure at Port 4 additive to the spring setting.
Parker’s N04 series of Pilot Operated Directional Valves are available with switching pressures of 73 psi and 145 psi, and are available with either Nitrile or Fluorocarbon seals.
