A fluid end having its fluid flow bores sealed without threading a retaining nut into the walls of each bore. The fluid ends may be assembled using a plurality of different kits that each comprise a fluid end body, a component, a retainer element, and a fastening system. The retainer element holds the component within each of the bores formed in the fluid end body and the fastening system secures the retainer element to the body. The fastening system comprises a plurality of externally threaded studs, washers and nuts in some embodiments. In other embodiments, the fastening system comprises a plurality of screws.

A hydrogen fueling station includes a cryogenic pump with a hydrogen piston at least partially positioned within a hydrogen pump cylinder. A variable volume working chamber is defined at least in part by the hydrogen piston, a seal extending around the piston, and an end portion of the hydrogen pump cylinder opposite the first end portion of the first hydrogen pump cylinder. The hydrogen pump cylinder is coupled with a coupler to a thermal decoupling cylinder. The seal provides hydrogen leakage at a first pressure in the variable volume working chamber to an area beneath the seal. A blow by seal mounted to the first coupler provides hydrogen leakage to the thermal decoupling cylinder. A relief valve provides hydrogen leakage out of the thermal decoupling cylinder. The first hydrogen pressure is greater than the second hydrogen pressure, and the second hydrogen pressure is greater than the third hydrogen pressure.

A hydrogen fueling station includes a cryogenic pump with a hydrogen piston at least partially positioned within a hydrogen pump cylinder. A variable volume working chamber is defined at least in part by the hydrogen piston, a seal extending around the piston, and an end portion of the hydrogen pump cylinder opposite the first end portion of the first hydrogen pump cylinder. The hydrogen pump cylinder is coupled with a coupler to a thermal decoupling cylinder. The seal provides hydrogen leakage at a first pressure in the variable volume working chamber to an area beneath the seal. A blow by seal mounted to the first coupler provides hydrogen leakage to the thermal decoupling cylinder. A relief valve provides hydrogen leakage out of the thermal decoupling cylinder. The first hydrogen pressure is greater than the second hydrogen pressure, and the second hydrogen pressure is greater than the third hydrogen pressure.

A control plate (18) of a hydraulic machine is described, the control plate (18) includes a body (21), an arrangement of openings (22, 23), and a contact face (24). In order to operate a hydraulic machine with a low noise level the body (21) is made of a plastic material. The control plate may be used as port plate or as valve plate.

A packing health monitoring system for a pump includes an isolation block arrangement having first and second connections, an integrated check valve, and means for securing the isolation block to a fluid end of the pump. A lubrication line which is coupled to a lubricant source connects to one of the first and second connections. A pressure sensor connects to the other for the first and second connections. The pressure sensor is configured to measure a back pressure within the fluid end. The packing health monitoring system further includes a control system in data communication with the pressure sensor; and an alert generator in data communication with the pressure sensor and the control system. The alert generator generates a first alert upon the control system determining the back pressure equals or exceeds a first predetermined threshold.

A packing health monitoring system for a pump includes an isolation block arrangement having first and second connections, an integrated check valve, and means for securing the isolation block to a fluid end of the pump. A lubrication line which is coupled to a lubricant source connects to one of the first and second connections. A pressure sensor connects to the other for the first and second connections. The pressure sensor is configured to measure a back pressure within the fluid end. The packing health monitoring system further includes a control system in data communication with the pressure sensor; and an alert generator in data communication with the pressure sensor and the control system. The alert generator generates a first alert upon the control system determining the back pressure equals or exceeds a first predetermined threshold.