Systems and methods for monitoring, detecting, and/or intervening with respect to cavitation and pulsation events during hydraulic fracturing operations may include a supervisory controller. The supervisory controller may be configured to receive pump signals indicative of one or more of pump discharge pressure, pump suction pressure, pump speed, or pump vibration associated with operation of the hydraulic fracturing pump. The supervisory controller also may be configured to receive blender signals indicative of one or more of blender flow rate or blender discharge pressure. Based on one or more of these signals, the supervisory controller may be configured to detect a cavitation event and/or a pulsation event. The supervisory controller may be configured to generate a cavitation notification signal indicative of detection of cavitation associated with operation of the hydraulic fracturing pump, and/or a pulsation notification signal indicative of detection of pulsation associated with operation of the hydraulic fracturing pump.

Systems and methods for monitoring, detecting, and/or intervening with respect to cavitation and pulsation events during hydraulic fracturing operations may include a supervisory controller. The supervisory controller may be configured to receive pump signals indicative of one or more of pump discharge pressure, pump suction pressure, pump speed, or pump vibration associated with operation of the hydraulic fracturing pump. The supervisory controller also may be configured to receive blender signals indicative of one or more of blender flow rate or blender discharge pressure. Based on one or more of these signals, the supervisory controller may be configured to detect a cavitation event and/or a pulsation event. The supervisory controller may be configured to generate a cavitation notification signal indicative of detection of cavitation associated with operation of the hydraulic fracturing pump, and/or a pulsation notification signal indicative of detection of pulsation associated with operation of the hydraulic fracturing pump.

A method for monitoring the functioning of a compressor, which is switchable into a delivery mode and, when in the delivery mode, delivers compressed air via a dryer line of a compressed-air preparation unit into at least one main supply line, from which multiple supply lines of compressed-air consumer circuits branch off, wherein a pressure sensor is connected at each of at least some of the supply lines, is disclosed. The method results in outputting a warning message if a weighted pressure gradient grd_p.sub.V_W has not exceeded a gradient limiting value grd_p.sub.G_W within a predefined monitoring time period T.sub.M.

Apparatus and methods for measuring backlash of a gear train of a pump unit for pumping a fluid. An example method may include locking a crankshaft of the pump unit such that the crankshaft cannot rotate. The method may further include commencing operation of a processing device to receive rotational position measurements indicative of rotational position of an output shaft of a prime mover, cause the prime mover to rotate the output shaft in a first direction until the output shaft reaches a first rotational position, and cause the prime mover to rotate the output shaft in a second direction until the output shaft reaches a second rotational position. The processing device may then determine backlash of the gear train by determining rotational distance between the first rotational position of the output shaft and the second rotational position of the output shaft.

Systems and methods for monitoring, detecting, and/or intervening with respect to cavitation and pulsation events during hydraulic fracturing operations may include a supervisory controller. The supervisory controller may be configured to receive pump signals indicative of one or more of pump discharge pressure, pump suction pressure, pump speed, or pump vibration associated with operation of the hydraulic fracturing pump. The supervisory controller also may be configured to receive blender signals indicative of one or more of blender flow rate or blender discharge pressure. Based on one or more of these signals, the supervisory controller may be configured to detect a cavitation event and/or a pulsation event. The supervisory controller may be configured to generate a cavitation notification signal indicative of detection of cavitation associated with operation of the hydraulic fracturing pump, and/or a pulsation notification signal indicative of detection of pulsation associated with operation of the hydraulic fracturing pump.

A compressor that includes a casing, a compression mechanism provided inside the casing to compress a refrigerant, a rotary shaft transmitting a rotational force to the compression mechanism from a drive source provided outside the casing, a clutch connecting the drive source and the rotary shaft by a magnetic force generated when electric power is applied to the clutch and disconnecting the drive source and the rotary shaft by losing the magnetic force when the electric power applied thereto is cut off, and a rotation measurement means for receiving the magnetic force from the clutch to measure a change in magnetic flux according to the rotation of the rotary shaft and measure a rotational speed of the rotary shaft. Thus, it is possible to measure the rotational speed of the rotary shaft without including a permanent magnet.

Systems and methods for monitoring, detecting, and/or intervening with respect to cavitation and pulsation events during hydraulic fracturing operations may include a supervisory controller. The supervisory controller may be configured to receive pump signals indicative of one or more of pump discharge pressure, pump suction pressure, pump speed, or pump vibration associated with operation of the hydraulic fracturing pump. The supervisory controller also may be configured to receive blender signals indicative of one or more of blender flow rate or blender discharge pressure. Based on one or more of these signals, the supervisory controller may be configured to detect a cavitation event and/or a pulsation event. The supervisory controller may be configured to generate a cavitation notification signal indicative of detection of cavitation associated with operation of the hydraulic fracturing pump, and/or a pulsation notification signal indicative of detection of pulsation associated with operation of the hydraulic fracturing pump.

A controller for operating a rod pumping unit at a pump speed. The controller includes a processor configured to operate a pump piston of the rod pumping unit at a first speed. The processor is further configured to determine a pump fillage level for a pump stroke based on a position signal and a load signal. The processor is further configured to reduce the pump speed to a second speed based on the pump fillage level for the pump stroke.

A method for monitoring the functioning of a compressor, which is switchable into a delivery mode and, when in the delivery mode, delivers compressed air via a dryer line of a compressed-air preparation unit into at least one main supply line, from which multiple supply lines of compressed-air consumer circuits branch off, wherein a pressure sensor is connected at each of at least some of the supply lines, is disclosed. The method results in outputting a warning message if a weighted pressure gradient grd_p.sub.V _W has not exceeded a gradient limiting value grd_p.sub.G_W within a predefined monitoring time period T.sub.M.

Aspects are provided for positive displacement pumps and methods and systems for controlling such positive displacement pumps for accurate volume dispensing. The pump may run a calibration procedure to determine a mapping between a pump speed and a flow rate for a current configuration of the positive displacement pump, a tubing size, and a fluid characteristic. A pump controller may determine a pump motion profile based on the mapping. The pump motion profile includes an acceleration phase, a constant speed phase, and a deceleration phase such that a total volume pumped according to the pump motion profile and the mapping is equal to a target volume. The pump controller may determine an adjustment to the pump motion profile based on a constant flow rate measured during operation. The pump controller may decelerate the positive displacement pump according to the adjusted pump motion profile until the target volume is dispensed.