A method is for testing a hydraulic system (1), having a pump (2) which, in a first direction of rotation (3), conveys fluid to a first consumer (4) for a volume flow function and, in a second direction of rotation (5), conveys fluid to at least one second consumer (6) for an actuation function. The method includes testing hydraulic readiness of the hydraulic system (1); drawing fluid into the hydraulic system (1); ventilating the hydraulic system (1). A hydraulic system (1) carries out such a method, having a pump (2) which can be driven in a first direction of rotation (3) for a volume flow function and can be driven in a second direction of rotation (5) for an actuation function.

An automatic water handling device of an air compressor includes a barrel and a pneumatic cylinder. The barrel has an interior space in which a division board formed with through holes is mounted to define a first chamber in which a desiccant agent is disposed and a second chamber. The barrel has a gas outlet opening connected with a gas accumulation tank. The second chamber has a gas inlet opening to receive compressed air. An electromagnetic valve is in connection with the second chamber and is connected to a timer for activation at predetermined time points by the timer to drive the pneumatic cylinder to open a control valve to drain off water removed from compressed air.

A flushing module for hydraulic drives, in particular for self-contained drives, for cleaning and/or replacing hydraulic medium. The flushing module has a pump and at least one shutoff valve and a housing. The flushing module is portable.

A valve system for use with a cylinder having an extensible rod, includes first and second valve assemblies, each including an inlet/outlet port configured to selectively be coupled with a source of pressurized gas, a check valve biased toward a closed state and having a check valve body at least partially receivable within a first port of the cylinder, a flow control valve positioned in series between the inlet/outlet port and the check valve, and an inlet pilot port connected with the check valve for opening the check valve when supplied with pressurized gas. First and second pilot lines extend to the respective inlet pilot ports from respective outlet pilot ports of the opposite ones of the first and second valve assemblies. When pressurized gas is supplied to the inlet/outlet port of a valve assembly, pressurized gas is also supplied to the opposite inlet pilot port.

A fluid system of a machine. The fluid system includes a fluid reservoir, a pump coupled to the fluid reservoir, a filter coupled to the pump and a valve assembly. The valve assembly includes a first port, a second port coupled to the first port and to the fluid reservoir, a third port coupled to the first port, and a first check valve positioned between the first port and the second port. The fluid system further includes a second check valve positioned between the filter and the third port.

A safety system has a valve block (10) to which at least one gas safety valve (12, 14) is connected in a detachable manner. At least one controllable valve (50, 52, 58) is in or at the valve block (10). At least one pressure accumulator (42) holds a gaseous pressure medium and is connected to the valve block (10) in a detachable manner. A gas-conveying connection routed at least partially within the valve block (10) between the connected pressure accumulator (42) and the connected gas safety valves (12, 14) can be opened or blocked by the valve (50, 52, 58).

A hydraulic tank protection system is disclosed. The hydraulic tank protection system may include a sensor to detect a characteristic of a fluid, a fluid control device to control a flow of the fluid into or out of a reservoir of a hydraulic tank, and an electronic control module to: receive, from the sensor, information indicating the characteristic of the fluid, determine, based on the characteristic of the fluid, whether the fluid comprises a first type of fluid, and selectively provide a control signal to actuate the fluid control device to control the flow of the fluid into or out of the reservoir based on whether the fluid comprises the first type of fluid.

A valve assembly having a plurality of fill valves that permit a fluid to flow from a fluid inlet into an interior flow path to increase a pressure of the fluid output from a fluid outlet, and a plurality of dump valves that permit the fluid to flow from the interior flow path to an exhaust to reduce the pressure of the fluid output from the fluid outlet. The valve assembly includes a controller that is configured for receipt of a command signal including a desired pressure of the fluid to be output from the fluid outlet, and is configured for receipt of a signal from a pressure sensor that is indicative of an actual pressure of the fluid output from the fluid outlet, wherein based on a comparison of the command signal with the signal indicative of the actual pressure, the controller is configured to selectively open and close each of the fill valves and each of the dump valves until the actual pressure is equal to the desired pressure.

A hydraulic drain system for a working machine including a hydrostatic pump, a tank, a cooler, a first conduit, and a second conduit. The hydrostatic pump is configured to be driven by a prime mover. The tank is configured to store fluid drained from the hydrostatic pump. The cooler is positioned upstream of the tank. The first conduit couples the hydrostatic pump to the cooler. The second conduit directly couples the hydrostatic pump to the tank.

A hydraulic drive unit includes: a pump; a pair of supply-discharge lines; a valve block; a sealed tank; a suction line that leads hydraulic oil in the sealed tank to the pump; a connecting line that connects an air vent port of the pump to the suction line; and a gas-liquid separator that separates air and the hydraulic oil flowing through the connecting line from each other. The pump is disposed upward of the valve block and the sealed tank in a vertical direction.