System for adjusting rate of spool centering in a pilot-controlled hydraulic spool valve

A device for adjusting rate of spool centering in a pilot-controlled hydraulic spool valve, the device comprising:

• a manifold comprising:
• a first pilot port adapted to connect to a first pilot fluid port of a pilot section,
• a second pilot port adapted to connect to a second pilot fluid port of the pilot section,
• a first valve port adapted to connect to a first control port of a hydraulic spool valve, and
• a second valve port adapted to connect to a second control port of the hydraulic spool valve;
• a first hydraulic circuit disposed inside the manifold, the first hydraulic circuit connecting the first pilot port and the first valve port, wherein the first hydraulic circuit comprises a first bypass branch, a first controlled-flow branch, and a first valve that is coupled to the second pilot port, wherein the first valve permits flow in the first bypass branch when the second pilot port is associated with a first hydraulic fluid pressure;
• and wherein the first valve blocks flow in the first bypass branch when the second pilot port is associated with a second hydraulic fluid pressure that is lower than the first hydraulic fluid pressure;
• and
• a second hydraulic circuit disposed inside the manifold, the second hydraulic circuit connecting the second pilot port and the second valve port, wherein the second hydraulic circuit comprises a second bypass branch, a second controlled-flow branch, and a second valve that is coupled to the first pilot port, wherein the second valve permits flow in the second bypass branch when the first pilot port is associated with a third hydraulic fluid pressure;
• and wherein the second valve blocks flow in the second bypass branch when the first pilot port is associated with a fourth hydraulic fluid pressure that is lower than the third hydraulic fluid pressure.

A system for adjusting rate of spool centering in a pilot-controlled hydraulic spool valve, the system comprising:

• a pilot valve configured to receive control signal from an operator;
• a flow control device configured to receive hydraulic fluid from the pilot valve;
• a main hydraulic valve configured to receive hydraulic fluid from the flow control device;
• and
• wherein the flow control device comprises:
• a first pilot port adapted to connect to a first pilot fluid port of the pilot valve,
• a second pilot port adapted to connect to a second pilot fluid port of the pilot valve,
• a first valve port adapted to connect to a first control port of the main hydraulic valve,
• a second valve port adapted to connect to a second control port of the main hydraulic valve,
• a first hydraulic circuit connecting the first pilot port and the first valve port, wherein the first hydraulic circuit comprises a first bypass branch, a first controlled-flow branch, and a first valve that is in series with the first bypass branch and that is coupled to the second pilot port;
• and
• a second hydraulic circuit connecting the second pilot port and the second valve port, wherein the second hydraulic circuit comprises a second bypass branch, a second controlled-flow branch, and a second valve that is in series with the second bypass branch and that is coupled to the first pilot port.