A pressure washer includes a prime mover, a water pump, the water pump including a pump inlet for receiving fluid from a fluid source and a pump outlet for supplying a pressurized primary fluid, a jet pump including a primary fluid inlet fluidly coupled to the pump outlet, a secondary fluid inlet, and a fluid outlet, and a spray gun configured to be fluidly coupled to the fluid outlet of the jet pump, the spray gun including a spray gun outlet having a variable effective flow area. Wherein, in operation, in a high pressure operating mode, the pressurized primary fluid flows through the jet pump and exits through the fluid outlet of the jet pump, and in a high flow operating mode, the pressurized primary fluid flows through the jet pump and entrains a secondary fluid supplied through the secondary fluid inlet, resulting in a combined fluid flow.

A wellbore pumping system (10) has at least one jet pump (18, 20) disposed in a tubular string (12) inserted into a subsurface wellbore (II). An intake of the jet pump is in fluid communication with a subsurface reservoir. A discharge of the jet pump is in fluid communication with an interior of a tubular string extending to the surface. A fluid bypass (24, 26) fluidly connects the inlet and discharge of the jet pump. The fluid bypass in some embodiments is operable to enable fluid flow when a differential pressure of fluid pumped into the tubular string from the surface exceeds a predetermined pressure. Another aspect includes a pump system having two separately operable jet pumps in tandem in a wellbore tubular string.

A wellbore pumping system (10) has at least one jet pump (18, 20) disposed in a tubular string (12) inserted into a subsurface wellbore (II). An intake of the jet pump is in fluid communication with a subsurface reservoir. A discharge of the jet pump is in fluid communication with an interior of a tubular string extending to the surface. A fluid bypass (24, 26) fluidly connects the inlet and discharge of the jet pump. The fluid bypass in some embodiments is operable to enable fluid flow when a differential pressure of fluid pumped into the tubular string from the surface exceeds a predetermined pressure. Another aspect includes a pump system having two separately operable jet pumps in tandem in a wellbore tubular string.

Metering device for introducing a liquid additive into a main liquid flowing along a pipe, includes a pump for withdrawing additive from a container and metering it, this pump including a first inlet for receiving a flow of main liquid which drives the pump, a second inlet for picking up additive and an outlet for the resulting mixture; a Venturi installed in the pipe, and connected in parallel with the pump, the first pump inlet connected by a first line to the Venturi inlet while the outlet connected by a second line to the Venturi throat; a first element for varying the restriction at the Venturi neck, and a second element sensitive to the pressure drop across the pump for controlling the first element to reduce the bore section when the pressure drop across the pump increases, and increase the bore section when the pressure drop across the pump decreases.

Metering device for introducing a liquid additive into a main liquid flowing along a pipe, includes a pump for withdrawing additive from a container and metering it, this pump including a first inlet for receiving a flow of main liquid which drives the pump, a second inlet for picking up additive and an outlet for the resulting mixture; a Venturi installed in the pipe, and connected in parallel with the pump, the first pump inlet connected by a first line to the Venturi inlet while the outlet connected by a second line to the Venturi throat; a first element for varying the restriction at the Venturi neck, and a second element sensitive to the pressure drop across the pump for controlling the first element to reduce the bore section when the pressure drop across the pump increases, and increase the bore section when the pressure drop across the pump decreases.

A current generator for a swimming system may include multiple entrainment pumps that discharge a flow of water into a pool. The entrainment pumps may each have a nozzle, a venturi and an entrainment inlet. In use, the flow of water from the nozzle into the venturi causes water at the entrainment inlet to flow into the venturi along with water from the nozzle. Each entrainment pump is arranged such that the fluid that flows out of the venturi passage is directed within a main passage, and the flow from multiple venturis may be combined and may be directed at least partially against the force of gravity before that fluid is directed out of the main passage outlet and into the pool. In at least some implementations, the fluid flows for at least one foot between the venturi and the main passage outlet.

A current generator for a swimming system may include multiple entrainment pumps that discharge a flow of water into a pool. The entrainment pumps may each have a nozzle, a venturi and an entrainment inlet. In use, the flow of water from the nozzle into the venturi causes water at the entrainment inlet to flow into the venturi along with water from the nozzle. Each entrainment pump is arranged such that the fluid that flows out of the venturi passage is directed within a main passage, and the flow from multiple venturis may be combined and may be directed at least partially against the force of gravity before that fluid is directed out of the main passage outlet and into the pool. In at least some implementations, the fluid flows for at least one foot between the venturi and the main passage outlet.

A segmented fish pump system is provided. The segmented fish pump system includes a series of booster pump segments stacked upon an intake pump segment, forming an enclosed stream throughout, wherein each booster pump segment induces further upward flow, thereby minimizing the pressure and velocity needed for the intake pump of the intake pump segment. As a result, lessening trauma to fragile aquatic life at collection and further providing a nautical environment within the enclosed stream for the aquatic life to be transported as well as self-propelled to higher elevations.