When a pipe pressure of a common discharge pipe during an independent discharge step in which only one reciprocating pump among a plurality of reciprocating pumps discharges a fluid to the common discharge pipe differs from internal pressures in pump chambers of the respective reciprocating pumps at discharge step start point angles, a stroke adjustment mechanism adjusts, on the basis of a pressure difference ΔP therebetween, effective stroke lengths of cross heads connected to plungers of the predetermined reciprocating pumps so that the internal pressures in the pump chambers reach the pipe pressure at the discharge step start point angles.

A fuel power transfer system for an engine may include a cryogenic fuel supply, a fuel pump in fluid communication with the cryogenic fuel supply, a multi-position valve in fluid communication with the fuel pump and a combustion chamber of the engine, a fuel turbine operatively coupled to the fuel pump and having a primary discharge port in fluid communication with the combustion chamber, a primary heat exchanger in fluid communication between the multi-position valve and the fuel turbine, and a gearbox operatively coupled to the fuel turbine and the fuel pump and configured to transfer power from the fuel turbine to the engine.

A system for delivering pressurized fracking fluid to a well includes a high-pressure pump pumping proppant-free fluid, and a double-piston pressure transfer arrangement for transferring pressure from the proppant-free fluid to a fracking fluid. The pressure transfer arrangement includes first and second cylinder assemblies, each having a piston in sliding engagement within a first hollow cylinder so as to define first and second chambers of the first cylinder and third and fourth chambers of the second cylinder. A piston rod interconnects the pistons. A flow selector alternately directs high-pressure proppant-free fluid to the first chamber and the third chamber so as to act on the pistons, thereby applying pressure to fracking fluid within the second and fourth chambers, respectively, for delivery to the well in alternate power strokes. The faces of the pistons facing the first and third chambers have a smaller effective surface area than the faces towards the second and fourth chambers such that pressure in the fracking fluid remains lower than pressure in the proppant-free fluid.

The present disclosure relates generally to alternating tangential flow (ATF) perfusion pumping methods, including novel methods for generating positive and negative pressure at the point of use, and more particularly, to apparatuses, systems and methods for use of the same.

A fuel power transfer system for an engine may include a cryogenic fuel supply, a fuel pump in fluid communication with the cryogenic fuel supply, a multi-position valve in fluid communication with the fuel pump and a combustion chamber of the engine, a fuel turbine operatively coupled to the fuel pump and having a primary discharge port in fluid communication with the combustion chamber, a primary heat exchanger in fluid communication between the multi-position valve and the fuel turbine, and a gearbox operatively coupled to the fuel turbine and the fuel pump and configured to transfer power from the fuel turbine to the engine.

A fuel power transfer system for an engine may include a cryogenic fuel supply, a fuel pump in fluid communication with the cryogenic fuel supply, a multi-position valve in fluid communication with the fuel pump and a combustion chamber of the engine, a fuel turbine operatively coupled to the fuel pump and having a primary discharge port in fluid communication with the combustion chamber, a primary heat exchanger in fluid communication between the multi-position valve and the fuel turbine, and a gearbox operatively coupled to the fuel turbine and the fuel pump and configured to transfer power from the fuel turbine to the engine.

When a pipe pressure of a common discharge pipe during an independent discharge step in which only one reciprocating pump among a plurality of reciprocating pumps discharges a fluid to the common discharge pipe differs from internal pressures in pump chambers of the respective reciprocating pumps at discharge step start point angles, a stroke adjustment mechanism adjusts, on the basis of a pressure difference P therebetween, effective stroke lengths of cross heads connected to plungers of the predetermined reciprocating pumps so that the internal pressures in the pump chambers reach the pipe pressure at the discharge step start point angles.

A thick stock valve having a first through-opening, having a second through-opening and having a valve member associated with both through-openings. The valve member is mounted so as to be able to pivot about a pivot axis, wherein the valve member has a sealing face that is curved concentrically with the pivot axis. In a first state, the valve member releases the first through-opening and closes the second through-opening. In a second state, the valve member releases the second through-opening and closes the first through-opening. The valve member comprises a sealing part and a pivot part, wherein the pivot part is mounted so as to be able to rotate in the pivot axis and wherein the sealing part is connected to the pivot part via a connection structure.

A pump with a position indicator is disclosed. The pump includes a pump housing, wherein the pump housing includes a flexible bladder disposed therein; a first fluid zone, wherein the first fluid zone is operable to allow flow of a first fluid into and out of the first fluid zone; and a second fluid zone, wherein the second fluid zone is operable to allow flow of a second fluid into and out of the second fluid zone. The pump further includes a flexible position indicator disposed in the first fluid zone and in communication with the flexible bladder, wherein the flexible position indicator is operable to detect a linear position of the flexible bladder, and wherein the flexible bladder fluidly isolates the first fluid zone from the second fluid zone.

A well service pump system supplies high pressure working fluid to a well. The pump system includes a closed-loop hydraulic circuit for actuating a plurality of working pump assemblies. The pump system is powered by a motor, which transfers mechanical energy to a plurality of pumps, which, in turn, provide hydraulic fluid to operate hydraulic ram cylinders, and thereby operate the working pump assemblies. Each of the polished rods of the hydraulic ram cylinders is connected axially to a plunger rod end of the working fluid end cylinder to operate the working pump assembly.