A fluid container for a hydraulic unit comprises a container housing which has at least one connection part, which can be shut off by means of a shut-off device arranged in the fluid container. The container housing has at least one internal chamber and a channel for connecting the internal chamber to the hydraulic unit. The connection part and the shut-off device are combined in a separate module, which is connected to the container housing.

A device for holding a hydraulic cylinder stem in position includes a hydraulic block having series-connected primary and secondary check valves. The latter includes a secondary control stem having a secondary valve body and a seal. A first throttle upstream and a second throttle downstream are closed in a secondary control stem closed position where the seal tightly blocks the secondary check valve, each throttle having a tiny throttle closing gap, preferably 0.1 mm or less. The control stem can move axially into an intermediate position where the throttles remain closed, that is, have a tiny closing gap, but valve body and seal are lifted from a secondary valve seat. The control stem can be moved further into an opening position where the throttles are open, each having an opening gap much larger than the closing gap, and the valve body and seal are lifted from the valve seat.

A valve stem for use in a fluid flow control valve having a valve body configured to receive a portion of the valve stem and to enable the valve stem to selectively rotate within the valve body between a fully-open position, where fluid is permitted to flow through the fluid flow control valve, and a fully-closed position, where fluid is prevented from flowing through the fluid flow control valve. The valve stem includes an elongate valve stem arm having a first end and a second end and a valve stem head integrally formed with and fixedly attached to the second end of the valve stem arm. The valve stem head includes a fluid inlet formed in the valve stem head, and a fluid outlet formed in the valve stem head, and a fluid passage that directs fluid from the fluid inlet, through the valve stem, and out of the fluid outlet.

A valve stem for use in a fluid flow control valve having a valve body configured to receive a portion of the valve stem and to enable the valve stem to selectively rotate within the valve body between a fully-open position, where fluid is permitted to flow through the fluid flow control valve, and a fully-closed position, where fluid is prevented from flowing through the fluid flow control valve. The valve stem includes an elongate valve stem arm having a first end and a second end and a valve stem head integrally formed with and fixedly attached to the second end of the valve stem arm. The valve stem head includes a fluid inlet formed in the valve stem head, and a fluid outlet formed in the valve stem head, and a fluid passage that directs fluid from the fluid inlet, through the valve stem, and out of the fluid outlet.

A valve assembly for use in a fracturing pump including a valve member movable into and out of engagement with a valve seat body. The valve seat body includes an outer surface and an inner surface, the inner surface forming a fluid bore extending between a first end and a second end of the valve seat body. The body further includes a seating surface extending radially from the inner surface and facing the valve member, the seating surface having a recessed area. An insert is disposed in the recessed area forming at least a portion of the inner surface and at least portion of the seating surface. The valve seat body first end has a diameter different from a diameter valve seat body second. The difference between diameters allows the valve seat body outer surface to be supported by the fluid passageway.

A fuel nozzle metering valve that includes a spool having an inlet port and an outlet flow port, and a retainer assembled to one end of the spool. A valve liner houses a portion of the spool. The spool is configured to move back and forth within the valve liner. The metering valve is biased in a closed position in which the outlet flow port is disposed entirely within the valve liner. The valve is opened when the spool slides within the valve liner such that some portion of the outlet flow port extends beyond an end of the valve liner. The retainer has a stepped portion configured to abut an end of the retainer at a fuel flow pressure below the expected maximum fuel flow pressure to be used in the fuel nozzle metering valve.

A plug for a fluid valve has a stem extending along an axis between a first end and a second end, a tip secured to the first end of the stem, a plug body mounted to the stem toward the second end relative to the tip, and a valve seat between the tip and the plug body. The valve seat has a sealing surface that extends past an outer perimeter of the tip and is sized to engage a valve ring of the fluid valve, the valve seat defining an annular space that permits radial movement of the valve ring relative to the axis of the stem to align with the valve ring as pressure is applied to the valve seat.

A plug for a fluid valve has a stem extending along an axis between a first end and a second end, a tip secured to the first end of the stem, a plug body mounted to the stem toward the second end relative to the tip, and a valve seat between the tip and the plug body. The valve seat has a sealing surface that extends past an outer perimeter of the tip and is sized to engage a valve ring of the fluid valve, the valve seat defining an annular space that permits radial movement of the valve ring relative to the axis of the stem to align with the valve ring as pressure is applied to the valve seat.

A power end assembly includes a crankshaft section, a crosshead section, and a connector section coupled together by one, two, or more sets of stay rods. The power end may include one or more support plates that are coupled to the crankshaft section and/or crosshead section. The crosshead section includes a plurality of individual crosshead frames. The connector section may include a plurality of individual connector plates or may be a unitary connector plate. The power end is configured to be coupled to a fluid end assembly by coupling the fluid end assembly to the connector plates.

A breach detection system for an internal combustion engine having a crankcase, an intake manifold, a positive crankcase ventilation valve, a crankcase ventilation tube with a flow control system therein, and a pressure sensor between the flow control system and the crankcase. The flow control system subdivides the crankcase ventilation tube into a plurality of parallel conduits—a first conduit having a normally closed check valve that opens under a first preselected pressure drop in a first direction from the air intake to the crankcase, and a second conduit having either a second check valve that opens under a second preselected pressure drop in a second direction opposite the first direction or a restriction profile having a third preselected pressure drop that is the same in both the first and second direction. When the pressure sensor detects no pressure drop there is a breach in the system.