Abstract: An integrated three-way poppet valve is disclosed with an intermediate pilot port and an integral load holding check valve. The valve incorporates a reverse flow check poppet for load hold capability, which enables a lower cost solution compared to a combination of valves of similar functionality. A control method is also disclosed using an integrated three-way poppet valve to control the flow of hydraulic oil to a cylinder, hydraulic motor, or other hydraulic device in proportion to the amount of a current applied to a solenoid coil. Depending on the current applied, the valve blocks all flow or else permits flow from one inlet port to two outlet ports proportional to the current applied.

Abstract: An integrated three-way poppet valve is disclosed with an intermediate pilot port and an integral load holding check valve. The valve incorporates a reverse flow check poppet for load hold capability, which enables a lower cost solution compared to a combination of valves of similar functionality. A control method is also disclosed using an integrated three-way poppet valve to control the flow of hydraulic oil to a cylinder, hydraulic motor, or other hydraulic device in proportion to the amount of a current applied to a solenoid coil. Depending on the current applied, the valve blocks all flow or else permits flow from one inlet port to two outlet ports proportional to the current applied.

Abstract: An apparatus is provided which has sensors that detect pressure on opposite sides of a control valve which controls the flow of hydraulic fluid from a source to a hydraulic actuator. The sensors produce electrical signals indicating those pressures. In response to the sensor signals, a controller produces an output signal the operates a proportional control valve to thereby regulate pressure at a node of the hydraulic circuit. Several mechanisms are described that react to the pressure at the node by varying the pressure of the fluid being supplied to the main valve so that a controlled pressure level is achieved.

Abstract: A regeneration method for a hydraulic system enables the fluid being forced from a first actuator to be used to power a second actuator. Often the force of the load acting on a hydraulic actuator is used to move the actuator into a given position which motion forces fluid from the actuator. Rather than simply draining that fluid to the system tank, the fluid is routed to a second actuator to be powered when the pressure of the fluid draining at the first actuator is greater than the pressure required to power the second actuator. At other times the draining fluid can be used to drive the pump which has been configured to operate as a motor thereby driving the prime mover connected to the pump. Alternatively the draining fluid can be routed to an accumulator where it is stored under pressure until needed to power an actuator of the system. A unique bidirectional pilot operated poppet valve.

Abstract: A two-part, low friction, live loaded packing system for fire safety and low fugitive emission sealing (less than 500 ppm) of a valve stem at operating temperatures up to 450.degree. F. (232.degree. C.). One lower packing ring set around the valve stem has PTFE washers sandwiched between flexible graphite rings to provide fire safety and low friction. An upper packing ring set around the valve stem is closer to the loading source and has V-type PTFE rings to provide reliable low fugitive emission sealing and low friction. The live loading is optimized to maintain a seal at the upper packing set to less than 500 ppm leakage, minimize packing friction from both the upper and lower packing sets, and seal the lower packing set during fire safety tests.