A fieldbus solenoid valve system has a solenoid operated control valve mounted and operated by a solenoid pilot. A direct current power source is connected to a coil of the solenoid pilot and a driver for actuating the coil. A resistive element is in series with the power source, the driver, the solenoid and a ground. A frequency generator is connected to the circuit for creating a frequency pulse train to the coil having a characterization so as not to cause the solenoid pilot to actuate. The voltage is measured between the coil and resistive element and the measured voltage is compared to a base voltage value measured from the same circuit location. An indicator signal is displayed on the fieldbus solenoid valve system or externally when the measured voltage increases to a predetermined amount from said base voltage over time.

A system and method for detecting faults and optimiz-ing power usage of solenoid valves. The method includes obtaining a current signature of the solenoid coil, using a dedicated circuit to detect various features and using a pulse width modulation controller optimize the power output of the system. Additionally, using machine learning, the system can be optimized using data from the dedicated circuit.

Systems and method determine a fluid efficiency of a fluid that flows through a fluid power system. Characteristics of the fluid is monitored in real-time as the fluid flows through the fluid monitoring device that is coupled to the fluid power system as the fluid flows through the fluid power system. A fluid status is determined in real-time that is associated with fluid parameters of the fluid that is determined from the fluid parameters detected by the fluid monitoring device. The fluid status of the fluid is determined in real-time when the fluid status indicates that a corrective action is to be executed to increase a quality of the fluid and an assessment of the corrective action that is to be executed is generated based on the fluid parameters. Degradation of the components of the fluid power system increases without the corrective action being executed to the fluid.

The present invention relates to a device for detecting leaks in a hydraulic cylinder, comprising: a first pressure sensor for detecting a pressure value in a first pressure chamber of a hydraulic cylinder, a second pressure sensor for detecting a pressure value in a second pressure chamber of the hydraulic cylinder, an evaluation unit for continuously detecting the pressure values of the first pressure sensor and the second pressure sensor, the evaluation unit being designed to detect a leak, preferably an internal leak, in the hydraulic cylinder that deviates from the norm based on the pressure values recorded by the first pressure sensor and the second pressure sensor.

An abradable seal includes an outer ring arrangement and an energiser for urging said outer ring arrangement against an opposing surface, wherein an outermost surface of said outer ring arrangement defines a sealing surface of said abradable seal; wherein said outer ring arrangement is configured such that after a first period of operation said sealing surface suddenly transitions from having a relatively large surface area to having a relatively small surface area, so as to cause a sudden increase in internal leakage across the seal at said transition.

A system and method for the controlled lowering and lifting of a load are disclosed. The system and method may include operating a work machine having a hydraulic system including a hydraulic actuator for supporting a load, a first control valve in fluid communication with the actuator, and a controller for operating the first control valve. In one embodiment, the controller includes a first algorithm for operating the first control valve in a load lowering operation. When an operational fault within the hydraulic system is detected, the controller can be configured to enter into a safe lowering mode. In the safe lowering mode, the first algorithm is disabled and a pulse width modulation (PWM) current is sent from the controller to the first control valve. A user interface is provided to allow an operator to control the PWM current duty ratio to allow the load supported by the actuator to be lowered.

A piston-cylinder unit includes a piston delimiting at least one working chamber, in which a first seal for sealing at least one first working chamber is arranged either between the piston and cylinder or between a plunger connected to the piston and the cylinder. A second seal is arranged between the first seal and the first working chamber, and the piston-cylinder unit further includes a first channel arranged in the wall of the cylinder or in the piston, which joins the first seal and the second seal in the inner chamber of the cylinder. The first channel and/or a hydraulic line connected thereto may have a throttle device and/or a valve device. An electronic control and regulating device may have a diagnosis or monitoring function for a possible defect or failure of a seal. Multiple hydraulic devices may have such piston-cylinder units and respective control and such regulating devices.

The disclosure provides a method for testing a solenoid valve for triggering a safety valve having a single-acting fluidic drive and a positioner. The drive fluid pressure is increased by a first pressure difference. An attempt is made to switch the solenoid valve to the safety position. The drive fluid pressure is measured at a specified point in time that is selected such that the pressure in the drive fluid lowers at most by the first pressure difference. If the pressure in the drive fluid is higher than a reference pressure at the specified point in time, the functionality test of the solenoid valve is failed. The lowering of the pressure in the drive fluid is monitored over a defined period of time to make conclusions regarding the pressure generating system. The pressure does not fall below the operating pressure so the position of the valve member remains constant.

A system includes a mounting panel having diffusion-bonded metal plates that form a reservoir to contain a process fluid, multiple channels through which to flow the process fluid, and vias through which to flow the process fluid to and from process fluid control components attached to the mounting panel. At least a pair of the multiple channels are connected with the reservoir. A temperature sensor is attached to a top of the mounting panel, the temperature sensor in fluid communication with the reservoir through one of the vias. A set of inlet ports are attached to the mounting panel, the set of inlet ports to receive the process fluid. At least one outlet port is attached to the mounting panel, the at least one outlet port to output the process fluid from the mounting panel.

Provided is an arrangement and a method to detect an oil leakage between a first section and a second section of a hydraulic cylinder. A movable piston is arranged between the first and second section in a way that the piston changes position between the sections. The change in position is done in dependency of a difference between a first force, which acts at the first section on a first cross sectional area of the piston, and a second force, which acts at the second section on a second cross sectional area of the piston. The first section comprises hydraulic oil with a predefined first pressure, while the first force is calculated based on this pressure and based on the first area. The second section comprises hydraulic oil with a predefined second pressure, while the second force is calculated based on this pressure and based on the second area.