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 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 fixing device and a plunger pump are disclosed. The valve spring fixing device includes a spring fixing piece, which includes a first supporting surface and a second supporting surface located at two ends of the spring fixing piece, and an intermediate portion located between the first supporting surface and the second supporting surface; and a spring mounting portion connected with the intermediate portion and configured to mount a valve spring, the first supporting surface and the second supporting surface are configured to contact with a valve box to fix the valve spring fixing device.

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.