Poppet Type Logic Element
Parker’s logic valves offer system designers a versatile range of screw-in elements that, when used in the proper combinations, can provide flexible design solutions for many common cartridge valve applications. They offer system designers the advantage of applying cartridge valve technology in applications where the flow and pressure conditions may exceed the limits of typical cartridge valves. Logic valves are essentially high flow poppet or spool elements that are controlled by small pilot devices. They can be used to control flow, pressure, or direction, and when applied in the proper arrangements, can perform multi-task control functions. Parker’s logic valves offer system designers alternative products that can help reduce the size, cost, and complexity of integrated manifold systems.
Poppet type logic valves are 3 ported, 2-way on/off valves that switch flow between port 1 and port 2. The poppet’s on/off action is operated by controlling pilot oil at port 3 of the valve. A small low flow solenoid or pilot valve is an ideal control for this purpose. Parker offers vent-to open and pilot-to-close style poppet logic valves.
Note: Poppet logic valves are an unbalanced 2:1 ratio poppet design. The opening and closing of the poppet is dependent on the force balances on the areas of the poppet at port 1, port 2, and port 3.
Vent-to-open logic valves:
Vent-to-open logic valves are primarily used for unidirectional flow switching applications. The poppet in the vent-to-open logic valve is spring biased to the closed condition. The pilot oil source that operates the logic element is generated internally by direct pressure from either work port 1 or 2, depending on the option chosen. Venting the pilot oil at port 3 allows the valve to open and pass flow between port 1 and port 2 at the bias spring setting. Blocking the pilot at port 3 causes the valve to close. When closed, the 2:1 ratio poppet design provides a positive low leak seal. Because the pilot source is generated internally within the valve, vent-to-open logic valves are best suited for uni-directional applications.
Parker’s 16SLC1-C Vent-to-open logic element is a size 16 valve capable of up to 50 gpm, 3500 psi. Standard spring settings of 50, 75, 100, and 150 psi are available. Manufactured with hardened, precision ground parts for durability, the 16SLC1-C is only available with Polyurethane seals only.
Pilot-to-close logic valve:
Pilot-to-close logic elements are primarily used for bidirectional flow switching applications. The poppet in the pilot-to-close logic valve is spring biased to the closed condition. With no pilot signal at port 3, the valve will open allowing flow in either direction between work ports 1 and 2 once pressure at one of the work ports reaches the biased spring setting. Appling a sufficient externally generated pilot force to port 3 of the valve closes the poppet creating a low leak seal between port 1 and port 2.
2-way, 3-way, and 4-way Directional Control:
Poppet logic valves are typically used to perform high flow directional switching operations using small low power pilot valves to control the sequence of the directional operation.
• A single logic valve can be used to control 2-way, on/off switching.
• Multiple elements in a bridge arrangement can control 3-way or 4-way directional switching.
• Since each logic valve is individually controlled, the timing, sequence, and overlap of directional functions can be controlled very precisely.
• Uni-directional or bi-directional flow can be achieved, depending on the valve selected.
• Flows in excess of 80 gpm can be controlled through a single logic element, and more than one logic valve can be used in parallel to control flow in excess of the rated flow of a single element.
• Poppet construction provides a low leak directional control.
Parker offers a wide variety of pilot-to-close logic elements ranging from 15 gpm to 80 gpm, 3500 psi. Spring ranges of 50, 75, 100, and 150 psi are available. Manufactured with hardened, precision ground parts for durability, these valve are available with Polyurethane seals only.
Common applications for logic elements are directional control valves, creating 2 way, 3 way, and 4 way valves, usually using a solenoid operated cartridge valve. Bridge circuits capable of up to 80 gpm can be controlled with a size 10, low flow directional cartridge valve. Also common are pressure and flow control circuits.
These valves can be found in all markets but most commonly used in mobile construction equipment, aerial devices, cranes, and excavation equipment. Applications include, but are not limited to, boom extension/retraction, outrigger control, winch control, conveying, steering, and auger control.
Poppet type logic valves are 3 ported, 2-way on/off valves that switch flow between port 1 and port 2. The poppet’s on/off action is operated by controlling pilot oil at port 3 of the valve. A small low flow solenoid or pilot valve is an ideal control for this purpose. Parker offers vent-to open and pilot-to-close style poppet logic valves.
Note: Poppet logic valves are an unbalanced 2:1 ratio poppet design. The opening and closing of the poppet is dependent on the force balances on the areas of the poppet at port 1, port 2, and port 3.
Vent-to-open logic valves:
Vent-to-open logic valves are primarily used for unidirectional flow switching applications. The poppet in the vent-to-open logic valve is spring biased to the closed condition. The pilot oil source that operates the logic element is generated internally by direct pressure from either work port 1 or 2, depending on the option chosen. Venting the pilot oil at port 3 allows the valve to open and pass flow between port 1 and port 2 at the bias spring setting. Blocking the pilot at port 3 causes the valve to close. When closed, the 2:1 ratio poppet design provides a positive low leak seal. Because the pilot source is generated internally within the valve, vent-to-open logic valves are best suited for uni-directional applications.
Parker’s 16SLC1-C Vent-to-open logic element is a size 16 valve capable of up to 50 gpm, 3500 psi. Standard spring settings of 50, 75, 100, and 150 psi are available. Manufactured with hardened, precision ground parts for durability, the 16SLC1-C is only available with Polyurethane seals only.
Pilot-to-close logic valve:
Pilot-to-close logic elements are primarily used for bidirectional flow switching applications. The poppet in the pilot-to-close logic valve is spring biased to the closed condition. With no pilot signal at port 3, the valve will open allowing flow in either direction between work ports 1 and 2 once pressure at one of the work ports reaches the biased spring setting. Appling a sufficient externally generated pilot force to port 3 of the valve closes the poppet creating a low leak seal between port 1 and port 2.
2-way, 3-way, and 4-way Directional Control:
Poppet logic valves are typically used to perform high flow directional switching operations using small low power pilot valves to control the sequence of the directional operation.
• A single logic valve can be used to control 2-way, on/off switching.
• Multiple elements in a bridge arrangement can control 3-way or 4-way directional switching.
• Since each logic valve is individually controlled, the timing, sequence, and overlap of directional functions can be controlled very precisely.
• Uni-directional or bi-directional flow can be achieved, depending on the valve selected.
• Flows in excess of 80 gpm can be controlled through a single logic element, and more than one logic valve can be used in parallel to control flow in excess of the rated flow of a single element.
• Poppet construction provides a low leak directional control.
Parker offers a wide variety of pilot-to-close logic elements ranging from 15 gpm to 80 gpm, 3500 psi. Spring ranges of 50, 75, 100, and 150 psi are available. Manufactured with hardened, precision ground parts for durability, these valve are available with Polyurethane seals only.
Common applications for logic elements are directional control valves, creating 2 way, 3 way, and 4 way valves, usually using a solenoid operated cartridge valve. Bridge circuits capable of up to 80 gpm can be controlled with a size 10, low flow directional cartridge valve. Also common are pressure and flow control circuits.
These valves can be found in all markets but most commonly used in mobile construction equipment, aerial devices, cranes, and excavation equipment. Applications include, but are not limited to, boom extension/retraction, outrigger control, winch control, conveying, steering, and auger control.
