Abstract: A method for detecting abnormal direct current voltage measurement in a modular multilevel converter high voltage direct current transmission system is provided. In the method, a valve group voltage at a detection pole is obtained, voltages at voltage measurement points at the detection pole are collected, and comparison and determination are performed based on the actual arrangement of the voltage measurement points, and then whether an abnormal measurement occurs at each of the voltage measurement points is determined.

Abstract: A hydraulic end assembly structure of a plunger pump, comprising a valve housing assembly, a suction gland and a suction pressing cap. The suction gland is connected to the suction pressing cap, and the suction gland is connected to the valve housing assembly through the suction packing seal assembly.

Abstract: A fluid splitter, a fluid end, and a plunger pump are provided. The fluid splitter includes: a body having a shape of column and including a first end, a second end, and a side surface connecting the first end and the second end; a first opening, located at the side surface of the body; a first cavity, located at the first end; a first channel, communicated with the first opening and the first cavity, respectively, the first channel extending from the first opening to the first cavity and being configured to allow fluid to flow therethrough; a second opening, located at the side surface of the body; a second cavity, located at the second end; and a second channel, communicated with the second opening and the second cavity, respectively, the second channel extending from the second opening to the second cavity and being configured to allow fluid to flow therethrough.

Abstract: The application discloses a speed reducer and a fracturing apparatus, the speed reducer may be used to connect to a turbine engine and comprises a housing, a planet carrier, a connecting flange, a planet shaft, a planet gear, a sun gear, a ring gear, an input shaft and an output shaft; the housing may be connected to the planet carrier, the connecting flange may be connected to the planet carrier and may be used to connect to the turbine engine; the planet shaft may be connected to the planet carrier, the planet gear may be sleeved on the planet shaft, one end of the input shaft may be used to connect to an output end of the turbine engine and the other end of the input shaft may be sleeved with the sun gear which is engaged with the planet gear, the ring gear may be engaged with the planet gear and connected to the output shaft.

Abstract: A valve spring holder, a valve box, and a plunger pump. The valve spring holder includes a body part, a first supporting part, a second supporting part, a spring mounting part, and a limiting groove. The first supporting part is connected to a first end part of the body part. The second supporting part is connected to a second end part of the body part. The spring mounting part is connected to a middle part of the body part. The first supporting part includes a first supporting surface, the second supporting part includes a second supporting surface, the first supporting surface and the second supporting surface are in contact with the valve box, and the limiting groove is located in at least one of the first supporting part and second supporting part, and is exposed to at least one of the first supporting surface and second supporting surface.

Abstract: A hydraulic end assembly structure of a plunger pump, comprising a valve housing assembly, a suction gland and a suction pressing cap. The suction gland is connected to the suction pressing cap, and the suction gland is connected to the valve housing assembly through the suction packing seal assembly.

Abstract: The application discloses a speed reducer and a fracturing apparatus, the speed reducer may be used to connect to a turbine engine and comprises a housing, a planet carrier, a connecting flange, a planet shaft, a planet gear, a sun gear, a ring gear, an input shaft and an output shaft; the housing may be connected to the planet carrier, the connecting flange may be connected to the planet carrier and may be used to connect to the turbine engine; the planet shaft may be connected to the planet carrier, the planet gear may be sleeved on the planet shaft, one end of the input shaft may be used to connect to an output end of the turbine engine and the other end of the input shaft may be sleeved with the sun gear which is engaged with the planet gear, the ring gear may be engaged with the planet gear and connected to the output shaft.

Abstract: A cover, a fluid end and a plunger pump are provided. The cover includes: a body, the body being cylindrical, and the body including a first end, a second end, and a side surface connecting the first end and the second end; a main flow channel extending along an axis of the body; a plurality of subsidiary flow channels, each of the plurality of subsidiary flow channels being communicated with the main flow channel; a first opening, located at the first end and communicated with the main flow channel; and a plurality of second openings, located at the side surface of the body; each of the plurality of subsidiary flow channels being communicated with at least one of the plurality of second openings.

Abstract: A valve spring seat sleeve, a valve assembly, and a plunger pump are disclosed. The valve spring seat sleeve includes a cylindrical hollow structure, a first fluid hole, a first notch and a second notch; the cylindrical hollow structure includes a plunger passage; the first fluid hole passes through a sidewall of the cylindrical hollow structure and communicated with the plunger passage; the first notch and the second notch are located on a side of the cylindrical hollow structure opposite to the first fluid hole; the cylindrical hollow structure includes a first end portion, a second end portion and an intermediate portion, a center of the first fluid hole is located at the intermediate portion, the cylindrical hollow structure further includes a spring mounting portion located between the first notch and the second notch.

Abstract: A valve spring seat sleeve, a valve assembly, and a plunger pump are disclosed. The valve spring seat sleeve includes a cylindrical hollow structure, a first fluid hole, a first notch and a second notch; the cylindrical hollow structure includes a plunger passage; the first fluid hole passes through a sidewall of the cylindrical hollow structure and communicated with the plunger passage; the first notch and the second notch are located on a side of the cylindrical hollow structure opposite to the first fluid hole; the cylindrical hollow structure includes a first end portion, a second end portion and an intermediate portion, a center of the first fluid hole is located at the intermediate portion, the cylindrical hollow structure further includes a spring mounting portion located between the first notch and the second notch.

Abstract: A plunger, a hydraulic end and a plunger pump are disclosed. The plunger includes a plunger body, the plunger body includes a flow channel; a first liquid inlet hole is located in the plunger body and passes through the sidewall of the plunger body; the plunger body includes a first end portion and a second end portion, a flow channel extends from the first end portion to the second end portion, a part of the flow channel close to the first end portion is closed, the flow channel extends to the second end portion and forms a first opening, the first liquid inlet hole is communicated with the flow channel, the first valve assembly is located at the first opening, and is configured to allow fluid to flow out from the flow channel at the first opening and prevent fluid from flowing back to the flow channel from outside.

Abstract: A fluid splitter, a fluid end, and a plunger pump are provided. The fluid splitter includes: a body having a shape of column and including a first end, a second end, and a side surface connecting the first end and the second end; a first opening, located at the side surface of the body; a first cavity, located at the first end; a first channel, communicated with the first opening and the first cavity, respectively, the first channel extending from the first opening to the first cavity and being configured to allow fluid to flow therethrough; a second opening, located at the side surface of the body; a second cavity, located at the second end; and a second channel, communicated with the second opening and the second cavity, respectively, the second channel extending from the second opening to the second cavity and being configured to allow fluid to flow therethrough.

Abstract: Disclosed is a status monitoring and fault diagnosis system for a plunger pump, including a monitoring and fault diagnosis device. The monitoring and fault diagnosis device monitors and diagnoses a hydraulic end assembly of a plunger pump. The monitoring and fault diagnosis device further monitors and diagnoses a power end assembly and/or a reduction gearbox assembly. Beneficial effects: The diagnosis system monitors and diagnoses not only a hydraulic end assembly, but also a power end assembly and/or a reduction gearbox assembly, that is, an equipment fault can be accurately predetermined in time for an entire plunger pump, so that high-pressure, large-displacement, and continuous operation requirements on fracturing sites at present are better satisfied, and on-demand maintenance is adopted instead of regular examination and maintenance, thereby saving labor, time, and materials to achieve economic efficiency.

Abstract: Embodiments of the present disclosure provides an anti-loosening device and a plunger pump. The anti-loosening device includes a first bracket, a second bracket and an elastic member. The first bracket includes a first clamping part defining a first accommodating space; a first connecting part extending in a first direction and fixedly connected to the first clamping part; and a limiting part fixedly connected to the first clamping part via the first connecting part, wherein the limiting part protrudes from the first connecting part in a second direction perpendicular to the first direction. The second bracket includes a second clamping part defining a second accommodation space, wherein the second clamping part is opposite to the first clamping part in the first direction; and a second connecting part extending in the first direction and fixedly connected to the second clamping part.

Abstract: A low-pressure liquid inlet manifold and a fracturing apparatus are disclosed. The low-pressure liquid inlet manifold includes a main liquid inlet pipe and N liquid feeding pipes; the N liquid feeding pipes are arranged in sequence; each of the liquid feeding pipes includes a third end and a fourth end, the third end is communicated with the main liquid inlet pipe, and the fourth end is configured to provide low-pressure liquid to a plunger pump; and the low-pressure liquid inlet manifold further includes at least one auxiliary accumulator, which is connected with the main liquid inlet pipe and is arranged corresponding to at least one of the N liquid feeding pipes, an orthographic projection of the auxiliary accumulator on an axis of the main liquid inlet pipe overlaps with an orthographic projection of a corresponding liquid feeding pipe on the axis.

Abstract: Disclosed is a status monitoring and fault diagnosis system for a plunger pump, including a monitoring and fault diagnosis device. The monitoring and fault diagnosis device monitors and diagnoses a hydraulic end assembly of a plunger pump. The monitoring and fault diagnosis device further monitors and diagnoses a power end assembly and/or a reduction gearbox assembly. Beneficial effects: The diagnosis system monitors and diagnoses not only a hydraulic end assembly, but also a power end assembly and/or a reduction gearbox assembly, that is, an equipment fault can be accurately predetermined in time for an entire plunger pump, so that high-pressure, large-displacement, and continuous operation requirements on fracturing sites at present are better satisfied, and on-demand maintenance is adopted instead of regular examination and maintenance, thereby saving labor, time, and materials to achieve economic efficiency.

Abstract: A hydraulic end assembly structure of a plunger pump, comprising a valve housing assembly, a suction gland and a suction pressing cap. The suction gland is connected to the suction pressing cap, and the suction gland is connected to the valve housing assembly through the suction packing seal assembly.

Abstract: The present invention discloses a high-power five cylinder plunger pump. The high-power five cylinder plunger pump has a stroke of 10 inches, a cylinder spacing of 11.5 inches, and a braking power of 5000 HP. Beneficial effects: high power, large displacement; suitable for electric drive fracturing and turbine fracturing; an integral power end assembly or a split-type power end assembly could be selected according to specific operation conditions, thus better implementing the arrangement of fracturing units or fracturing vehicles; the dimension of the cylinder spacing ensures stable operations under a 5000 HP braking power with a long stroke.

Abstract: Disclosed is a status monitoring and fault diagnosis system for a plunger pump, including a monitoring and fault diagnosis device. The monitoring and fault diagnosis device monitors and diagnoses a hydraulic end assembly of a plunger pump. The monitoring and fault diagnosis device further monitors and diagnoses a power end assembly and/or a reduction gearbox assembly.

Abstract: The present invention discloses a five cylinder plunger pump with an integral power end structure. In the power end assembly of the five cylinder plunger pump, the crankcase and the crosshead case adopt an integral welding structure, so that the power end assembly has a higher structural strength and a better support stability to reduce vibration of the whole pump. The cylinder spacing is 13-14 inches, increasing the bearing area of the connecting rod, the crosshead and the bearing bushes, and ensuring the high power output of the five cylinder plunger pump. The high power five cylinder plunger pump can effectively solve the problems of narrow area in shale gas fracturing wellsite and the need for multiple fracturing equipment, thus reducing the use of equipment and facilitating the arrangement of the wellsite. The long stroke design of 11 inches is beneficial to realize the operation requirement of large displacement and enhance the operation efficiency.