Electrohydraulic normally-open ventable valve configured to operate in pressure relief mode when actuated

A hydraulic system comprising:

• a source of fluid;
• a reservoir;
• and
• a ventable pressure relief valve having a first port fluidly coupled to the source of fluid, and a second port fluidly coupled to the reservoir, wherein the ventable pressure relief valve comprises:
• a pilot seat member comprising:
• (i) one or more channels fluidly coupled to the first port, (ii) a pilot seat, and (iii) a pilot chamber,
• a pilot check member disposed in the pilot chamber and subjected to a biasing force of a setting spring disposed in the pilot chamber to seat the pilot check member at the pilot seat, and
• a solenoid actuator sleeve axially movable relative to the pilot seat member, wherein the solenoid actuator sleeve includes, wherein:
• when the ventable pressure relief valve is unactuated, the ventable pressure relief valve operates in a ventable mode of operation, wherein a first pilot flow path comprising the one or more channels of the pilot seat member is formed to fluidly couple the first port to the second port, thereby causing a piston to move and open a main flow path from the first port to the second port, and
• when the ventable pressure relief valve is actuated, the ventable pressure relief valve operates in a pressure relief mode of operation, wherein the solenoid actuator sleeve moves axially, thereby:
• (i) blocking the first pilot flow path, and (ii) causing the piston to block the main flow path from the first port to the second port, wherein when pressure level of fluid at the first port overcomes the biasing force of the setting spring on the pilot check member, the pilot check member is unseated and a second pilot flow path is formed from the first port to the second port, thereby causing the piston to move axially and open the main flow path from the first port to the second port.

A valve comprising:

• a housing having a longitudinal cylindrical cavity therein and having a cross-hole disposed in an exterior peripheral surface of the housing;
• a main sleeve disposed, at least partially, in the longitudinal cylindrical cavity of the housing, wherein the main sleeve includes a first port at a distal end of the main sleeve and includes one or more cross-holes disposed on an exterior peripheral surface of the main sleeve, wherein the cross-hole of the housing and the one or more cross-holes of the main sleeve form a second port;
• a piston disposed within the main sleeve and configured to be axially movable therein, wherein the piston defines a main chamber therein, and wherein the main chamber is fluidly coupled to the first port;
• a pilot seat member comprising:
• (i) one or more channels fluidly coupled to the main chamber, (ii) a pilot seat, and (iii) a pilot chamber;
• a pilot check member disposed in the pilot chamber and subjected to a biasing force of a setting spring disposed in the pilot chamber to seat the pilot check member at the pilot seat;
• and
• a solenoid actuator sleeve axially movable relative to the pilot seat member, wherein when the valve is unactuated, the solenoid actuator sleeve is in a first position in which a first pilot flow path comprising the one or more channels of the pilot seat member is formed to fluidly couple the first port to the second port, and wherein when the valve is actuated, the solenoid actuator sleeve moves axially to a second position in which the first pilot flow path is blocked, and a second pilot flow path is formed from the first port to the second port when pressure level of fluid at the first port overcomes the biasing force of the setting spring on the pilot check member.