Apparatus and methods for reducing pressure exchanger manifold resonance. Example apparatus include a first manifold and pumps fluidly connected with the first manifold. Each pump is operable to inject a pressurized clean fluid into the first manifold. The apparatus may further include a second manifold and pressure exchangers each fluidly connected with the first and second manifolds. Each pressure exchanger is operable to receive the pressurized clean fluid from the first manifold and discharge the pressurized dirty fluid into the second manifold. The apparatus may also include a first flow restricting orifice fluidly connected along the first manifold, a second flow restricting orifice fluidly connected along the second manifold, and a discharge conduit fluidly connected with the wellbore to permit the pressurized dirty fluid to be injected into the wellbore during a well treatment operation.

A pressure reduction plant including two or more valve assemblies arranged in parallel and including: pressure reducers for fuel gas from the supply pressure to the delivery pressure; pilot valves to transmit a control pressure to the pressure reducers when the delivery pressure reaches the calibration value of the pilot valves; derivation conduits to transmit the delivery pressure to the pressure reducers, the pilot valves and the pressure reducer devices; command lines to transmit the control pressure from the pilot valves to the pressure reducers. One of the pilot valves is configured with a calibration value greater than the calibration value of all the remaining pilot valves and each command line is configured to communicate with a control line.

An example valve assembly is configured: generate a valve load-sense pressure signal indicative of a pressure level at a workport of an actuator; generate a pilot fluid signal to be communicated to a worksection of a valve assembly to enable shifting a spool in the worksection; compare a first pressure level of the valve load-sense pressure signal to a second pressure level of the pilot fluid signal; and communicate the pilot fluid signal to a load-sense port fluidly coupled to a load-sensing source of pressurized fluid when the second pressure level of the pilot fluid signal exceeds the first pressure level of the valve load-sense pressure signal.

Disclosed is a load-sensing multi-way valve work section comprising a valve body, which comprises a compensation valve and a reversing valve both formed therein, wherein the compensation valve is provided with a compensation valve bore formed in the valve body and a compensation valve spool accommodated in the compensation valve bore, with a compensation valve oil inlet chamber, a compensation valve oil outlet chamber, a spring-side control chamber and a springless-side control chamber all being formed inside the compensation valve bore; wherein the reversing valve is provided with a reversing valve bore formed in the valve body and a reversing valve spool accommodated in the reversing valve bore, the reversing valve spool being configured to control communications among a main oil inlet chamber, a first working oil chamber, a second working oil chamber, a first oil return chamber, a second oil return chamber, a first load-sensing feedback pressure sensing opening and a second load-sensing feedback pressure sensing opening formed in the reversing valve bore, the compensation valve oil outlet chamber being communicated to the main oil inlet chamber; and wherein the load-sensing multi-way valve work section also defines a feedback passage formed within the valve body, the feedback passage being configured to communicate one of the first and second load-sensing feedback pressure sensing openings with the spring-side control chamber depending on a position of the reversing valve spool in the reversing valve bore.

A system includes a first pressure-adjusting device positioned in a first line and a second pressure-adjusting device positioned in a second line. The first pressure-adjusting device is actuated solely via a first pneumatic signal output from a first pilot valve to control a downstream pressure in the first line. The second pressure-adjusting device is actuated via the first pneumatic signal in a first mode of operation, and is actuated via a second pneumatic signal output from a second pilot valve in a second mode of operation to control a downstream pressure in the second line.

One aspect relates to an engine including a working system, having a first piston-cylinder system, comprising a working piston and a working cylinder. The working piston divides the working cylinder into a first working cylinder portion and a second working cylinder portion, a valve system, having a first valve connection and a valve element. The valve system and the working system are connected in a gas conducting manner, the first valve connection can be connected to a negative pressure source, and the valve element is movably arranged in the valve system such that, in a first valve position, the valve element connects the first valve connection to the first working cylinder portion, and, in a second valve position, connects the first valve connection to the second working cylinder portion in a gas conducting manner. One aspect furthermore relates to a medical device having the engine and a method for treating a mammal.

The present invention relates to a liquid metering device (1) for metering pumps which is formed by a main longitudinal conduit (2) with a first and second opposite ends (2.1, 2.2) comprising a fluid inlet (3) at the first end (2.1) located perpendicular thereto, a first outlet (4) at the second end (2.2), and a first connection (5) to backpressure control means (6), a second connection (7) to safety means (8), acting in parallel and in an independent manner, and a second overpressure outlet (9), arranged in one and the same connecting section (10), and where said connecting section (10) has an inclined wall (11) allowing the fluid to exit through the first outlet (4) for a fluid pressure equal to or greater than a fixed backpressure value and the fluid to exit through the second outlet (9) for a pressure greater than a fixed value.

An example valve assembly is configured: generate a valve load-sense pressure signal indicative of a pressure level at a workport of an actuator; generate a pilot fluid signal to be communicated to a worksection of a valve assembly to enable shifting a spool in the worksection; compare a first pressure level of the valve load-sense pressure signal to a second pressure level of the pilot fluid signal; and communicate the pilot fluid signal to a load-sense port fluidly coupled to a load-sensing source of pressurized fluid when the second pressure level of the pilot fluid signal exceeds the first pressure level of the valve load-sense pressure signal.

The present invention relates to a liquid metering device (1) for metering pumps which is formed by a main longitudinal conduit (2) with a first and second opposite ends (2.1, 2.2) comprising a fluid inlet (3) at the first end (2.1) located perpendicular thereto, a first outlet (4) at the second end (2.2), and a first connection (5) to backpressure control means (6), a second connection (7) to safety means (8), acting in parallel and in an independent manner, and a second overpressure outlet (9), arranged in one and the same connecting section (10), and where said connecting section (10) has an inclined wall (11) allowing the fluid to exit through the first outlet (4) for a fluid pressure equal to or greater than a fixed backpressure value and the fluid to exit through the second outlet (9) for a pressure greater than a fixed value.

A hydraulic system for a transmission of a motor vehicle, the system having first and second pumps for conveying hydraulic fluid into primary and/or system-pressure circuits so that an intended pressure prevails in the circuits. The system further including liquid retention means preventing a flow of hydraulic fluid conveyed by the second pump from being conducted through the first pump when the first pump is not conveying and the second pump is conveying, and preventing a flow of hydraulic fluid conveyed by the first pump from being conducted through the second pump when the second pump is not conveying and the first pump is conveying. The system additionally including a sailing-mode lubricating valve for controlling, by an open-loop system, a flow rate of hydraulic fluid conveyed by the second pump into the primary and/or secondary system-pressure circuits such that the intended pressure is set in the system-pressure circuits.