A compressor is disclosed. In one aspect, the compressor includes a pressure chamber which is delimited by at least two housing parts, the housing parts including sealing surfaces that are connected by a connection device which applies a contact pressing force between the sealing surfaces. At least one groove extending in a circumferential direction is arranged on at least one sealing surface. At least one relief opening is arranged on at least one of the housing parts. The relief opening connects the groove to the surroundings of the compressor and emanates from the groove. The groove is arranged such that when a predetermined maximum pressure is exceeded in the pressure chamber, a pressure-building medium can gather in the groove and at least partially escape through the relief opening.

A multi-mode air compressor pressure switch is disclosed. A first mode of operation of the switch has a first range that includes a first cut-out pressure and a first cut-in pressure. A second mode of operation of the switch has a second range that includes a second cut-out pressure and a second cut-in pressure. The second range is smaller than the first range. The second mode of operation adds compressor output over the first mode of operation to extend operable time of a tool that is connected to a compressor that is controlled by the first mode and the second mode.

The present disclosure describes a load/unload control method for a compressor system with a rotating compressor connected to a pressure vessel. In the method, the present operating state can be monitored on the basis of a monitored/estimated electrical quantity of the compressor system, The method comprises an identification phase and an operational phase. In the identification phase, the compressor is operated at a constant rotational speed to generate two known pressures to the pressure vessel. At least one electrical quantity is monitored, and values of the electrical quantity corresponding to the pressure limits are stored. In the operational phase, reaching of a pressure limit may then be detected by comparing the present value of the monitored electrical quantity to the stored values.

An operation method of a turbine fracturing device and a turbine fracturing device are provided. The turbine fracturing device includes a turbine engine, a speed reducer, a brake mechanism, and a fracturing pump, the method includes: driving, by the turbine engine, the fracturing pump to perform a fracturing operation through the speed reducer so as to keep the fracturing pump in an operating state, the fracturing pump being configured to suck fluid of a first pressure and discharge fluid of a second pressure, the second pressure being greater than the first pressure; and in response to an idling instruction, the turbine engine entering an idling state and triggering a brake operation so as to keep the fracturing pump in a non-operating state.

A method of operating a vacuum pump system, the method including the steps of: operating a primary vacuum pump having a variable speed motor; connecting at least two secondary vacuum pumps in parallel with said primary vacuum pump; dividing the secondary vacuum pumps in groups, each group including at least one secondary vacuum pump; and assigning a priority for each of said groups. The method further includes the steps of measuring the inlet pressure p1, comparing the measured inlet pressure p1 with a predetermined pressure value p0, and if p1 is higher than p0, starting the secondary vacuum pump at a first predetermined startup load S.sub.startup,1 if it includes a fixed speed motor, and/or starting the secondary vacuum pump at a second predetermined startup load S.sub.startup,2, if it includes a variable speed motor.

Systems and methods for operating hydraulic fracturing units, each including a hydraulic fracturing pump to pump fracturing fluid into a wellhead and an internal combustion engine to drive the hydraulic fracturing pump, may include receiving signals indicative of operational parameters. The systems and methods also may include determining an amount of required fracturing power sufficient to perform the hydraulic fracturing operation, determining an available power to perform the hydraulic fracturing operation and a difference between the available power and the required power, and controlling operation of the hydraulic fracturing units based at least in part on the power difference. When the power difference is indicative of excess power available, the system and methods may include causing at least one of the hydraulic fracturing units to idle, and when the power difference is indicative of a power deficit, increasing a power output of at least one of the hydraulic fracturing units.

The purpose of the present invention is to provide an air compressing apparatus capable of establishing a sufficient air-filling rate while reducing noise at the initiation of operations. To solve this problem, in the present invention, the air compressing apparatus comprises a compressor body that compresses air, a motor that drives the compressor body, an inverter that controls the rotation speed of the motor, a control circuit connected to the inverter, and a pressure sensor that detects the pressure of air compressed in the compressor body, wherein the control circuit controls operation of the compressor body by operating at a low speed activation mode that operates the compressor body at a low speed rotational frequency lower than a maximum rotational speed when the air compressing apparatus is activated, and on the basis of a pressure value detected by the pressure sensor and elapsed time from activation, switching from the low speed activation mode to a normal operating mode that operates at variable frequencies including a maximum rotational frequency.

A system and method is provided for monitoring a hydraulic power system having at least one light emitter and a button. The method includes powering on the hydraulic power system, receiving an actuation at the button and detecting a release of the button after a first time interval, and entering a diagnostic state. The method further includes retrieving a code and displaying the code by turning on the emitter in a first pattern. In some embodiments, a system and method is provided for regulating a temperature of a hydraulic power system. In some embodiments, a system and method is provided for controlling operation of a hydraulic torque wrench.

Provided is a compressor including: a compressor body that has a motor and compresses air; an aftercooler for cooling the compressed air supplied from the compressor body; a dryer for dehumidifying the compressed air flowing out from the aftercooler; a drain discharge valve for discharging a drain from the dryer; a first pressure sensor for measuring air pressure downstream of the aftercooler; and a control device having a rotation-speed adjusting unit that drives the motor at second acceleration smaller than first acceleration, the first acceleration being rated acceleration of the motor, when a pressure value measured by the first pressure sensor is less than a first threshold value predetermined at startup of the motor.

A multi-stage compressor includes a compression module configured to compress a refrigerant therein through reciprocation of a plurality of pistons provided in a front housing, a rear housing coupled to the front housing to define an internal space between the front housing and the rear housing; a separation plate located between the front housing and the rear housing to separate the internal space between the front housing and the rear housing into a front space and a rear space; and a partition wall coupled to the rear housing to partition the rear space into an injection space before a refrigerant injected thereinto is primarily compressed, a primary discharge space from which the refrigerant is discharged in a primary compressed state by some of the pistons, and a secondary discharge space from which the primary compressed refrigerant is discharged.