A pump system includes a housing defining a first internal volume and a second internal volume, a first piston positioned to separate the first internal volume into a first chamber and a second chamber, a second piston positioned to separate the second internal volume into a third chamber and a fourth chamber, a directional control valve (DCV) fluidly coupled to the second chamber and the fourth chamber, a first relief valve fluidly coupled to the DCV via a first control line and the second chamber via a first sensing line, a first orifice positioned along the first sensing line, a second relief valve fluidly coupled to the DCV via a second control line and the fourth chamber via a second sensing line, and a second orifice positioned along the second sensing line.

A compressor includes a cylinder block having a first bore and a cylinder head overlapping the cylinder block. The cylinder head has a second bore aligned with the first bore. The second bore is separated into a plurality of distinct regions including a suction region and an economizer region. A plurality of valves includes a suction valve selectively operable to fluidly couple the suction region and the first bore, and an economizer valve selectively operable to fluidly couple the economizer region and the first bore.

A compressor includes a cylinder block having a first bore and a cylinder head overlapping the cylinder block. The cylinder head has a second bore aligned with the first bore. The second bore is separated into a plurality of distinct regions including a suction region and an economizer region. A plurality of valves includes a suction valve selectively operable to fluidly couple the suction region and the first bore, and an economizer valve selectively operable to fluidly couple the economizer region and the first bore.

A valved manifold module is disclosed, constructed and arranged to be readily connected in a chain with similar modules to form a manifold assembly. The modular manifolds allows for expansion or modification of the manifold assembly to control a group of pneumatically or hydraulically driven pumps, valves or combinations thereof in a liquid flow control apparatus. The valved manifold module can be configured to accept a group of four substantially identical valve assemblies, and can be controlled by a local controller mounted to the manifold module, thus forming an independently programmable valved manifold module. The resulting modular system is expandable to allow for coordinated operations of a liquid flow control system, using substantially independent controller functions originating at the manifold assembly level.

A valved manifold module is disclosed, constructed and arranged to be readily connected in a chain with similar modules to form a manifold assembly. The modular manifolds allows for expansion or modification of the manifold assembly to control a group of pneumatically or hydraulically driven pumps, valves or combinations thereof in a liquid flow control apparatus. The valved manifold module can be configured to accept a group of four substantially identical valve assemblies, and can be controlled by a local controller mounted to the manifold module, thus forming an independently programmable valved manifold module. The resulting modular system is expandable to allow for coordinated operations of a liquid flow control system, using substantially independent controller functions originating at the manifold assembly level.

A pump arrangement, in particular in a coating installation for the coating of components, such as a painting installation for the painting of motor vehicle body components, is provided. The pump arrangement includes a plurality of adjustable pumps for delivering a coating agent, e.g. for delivering a sealing agent for the sealing of weld seams on a motor vehicle body component. The pumps are connected in parallel such that the pumps extract the coating agent for delivery from a common inlet line and deliver said coating agent into a common outlet line. The arrangement further includes a control device for the open-loop or closed-loop control of one fluid variable at the outlet of the individual pumps, respectively, wherein the control device actuates the individual pumps individually, and/or a monitoring unit, which switches the pumps on and off non-simultaneously.

A pump arrangement, in particular in a coating installation for the coating of components, such as a painting installation for the painting of motor vehicle body components, is provided. The pump arrangement includes a plurality of adjustable pumps for delivering a coating agent, e.g. for delivering a sealing agent for the sealing of weld seams on a motor vehicle body component. The pumps are connected in parallel such that the pumps extract the coating agent for delivery from a common inlet line and deliver said coating agent into a common outlet line. The arrangement further includes a control device for the open-loop or closed-loop control of one fluid variable at the outlet of the individual pumps, respectively, wherein the control device actuates the individual pumps individually, and/or a monitoring unit, which switches the pumps on and off non-simultaneously.

A pump comprises: a plurality of pistons each of which is slidable inside a cylinder so as to vary volume of a corresponding chamber, a plurality of suction valves, each of which is associated with a chamber and is operable to allow a liquid to enter the chamber, the suction valves being arranged in a first sequence, a plurality of delivery valves, each of which is associated with a chamber and is operable to allow said liquid to exit from the chamber, the delivery valves being arranged in a second sequence, an adjusting valve for adjusting pressure of the liquid exiting from the pump.

The adjusting valve is interposed between two consecutive valves of a sequence chosen from said first sequence and said second sequence.

The pump further comprises: an outlet conduit arranged downstream of the delivery valves, a shutter device interposed between an initial portion of the outlet conduit and a final portion of the outlet conduit, so as to put the initial portion in fluid communication with the final portion, or alternatively separate the initial portion from the final portion, a connecting hole for connecting a portion of the outlet conduit arranged downstream of the shutter device with the adjusting valve.

A hydraulic apparatus comprises first and second manifolds each of which is connected to a plurality of actuators via corresponding actuator valves connected in parallel and operated responsive to inputs to regulate the flow of fluid to the actuators. A plurality of working chambers are connectable to either the first or second manifold and have a net flow which is controlled responsive to a negative feedback signal. The negative feedback signal is determined in response to a calculated pressure or flow rate in virtual fluid flow paths extending from the first and second manifolds.

A system and method for independent control of simultaneous fracturing for multiple wellbores is disclosed. In certain embodiments, a first clean pumping unit and a first dirty pumping unit are fluidically coupled to a first wellbore, wherein the first clean pumping unit pumps a first fluid to the first wellbore and the second clean pumping unit pumps a second fluid to the first wellbore. In certain embodiments, a second clean pumping unit and a second dirty pumping unit are fluidically coupled to a second wellbore, wherein the second clean pumping unit pumps the first fluid to the second wellbore and the second dirty pumping unit pumps. In certain embodiments, a controller controls a pumping rate of at least one of the first clean pumping unit and the first dirty pumping unit based on a desired parameter of a combined fluid pumped to the first wellbore.