Adjustable pilot-actuated valve

An adjustable pilot-actuated valve (230), comprising:

• a housing (331) forming a valve chamber (332), a first piston chamber (338), and a second piston chamber (340);
• a valve spool (333) movable within the valve chamber (332);
• a first piston (334) movable within the first piston chamber (338) and including a first side (334a) and a second side (334b) with the second side (334b) coupled to the valve spool (333);
• a second piston (335) movable within the second piston chamber (340) and including a first side (335a) and a second side (335b) with the second side (335b) coupled to the valve spool (333);
• a first pilot port (234) formed in the housing (331) to receive a first pilot pressure and in fluid communication with the first side (334a) of the first piston (334);
• a second pilot port (235) formed in the housing (331) to receive a second pilot pressure and in fluid communication with the first side (335a) of the first piston (335);
• a biasing spring (460) acting on the first side (334a) of the second piston (335) and providing a biasing force on the valve spool (333) in a first direction;
• and
• an adjustment member (461) movable relative to the housing (331) and contacting the biasing spring (460) to adjust the biasing force of the biasing spring (460).

A fluid operated actuator system (200), comprising:

• a fluid operated actuator (201) including a housing (202), a piston (203) movable within the housing (202) and separating the housing (202) into a first fluid chamber (205a) and a second fluid chamber (205b);
• a control valve (210) including a first port (211) in fluid communication with a pressurized fluid source (250) and movable between a first position and a second position to selectively open a fluid communication path between the first port (211) and a second port (212) or the first port (211) and a third port (213);
• a balance valve (220) in fluid communication with the first and second fluid chambers (205a, 205b) and movable between a first position and a second position including:
• a first port (221) in fluid communication with the second port (212) of the control valve (210);
• a second port (222) in fluid communication with the third port (213) of the control valve (210);
• a pilot port (227) to receive a pilot pressure;
• wherein if the pilot pressure is less than a threshold pressure, the balance valve (220) actuates to the first position to provide fluid communication between the control valve (210) and the fluid operated actuator (201);
• wherein if the pilot pressure reaches a threshold pressure, the balance valve (220) actuates to the second position to provide fluid communication between the first and second fluid chambers (205a, 205b);
• an adjustable pilot-actuated valve (230) movable between a first position and a second position including:
• a first port (231) in fluid communication with the pilot port (227) of the balance valve (220);
• a second port (232) comprising an exhaust;
• a third port (233) in fluid communication with the pressurized fluid supply (250);
• a first pilot port (234) in fluid communication with the first fluid chamber (205a);
• a second pilot port (235) in fluid communication with the second fluid chamber (205b);
• wherein the adjustable pilot-actuated valve (230) actuates to the first position to exhaust pressurized fluid acting on the pilot port (227) of the balance valve (220) if a pressure differential between the first fluid chamber (205a) and the second fluid chamber (205b) is less than a threshold difference;
• and
• wherein the adjustable pilot-actuated valve (230) actuates to a second position to supply at least the threshold pilot pressure to the pilot port (227) to actuate the balance valve (220) to the second position if the pressure differential between the first fluid chamber (205a) and the second fluid chamber (205b) reaches the threshold difference.