A control valve for a reverse osmosis water purifying system provides a feed water port, a squeeze water port, a drain port, and a product water connection, each of which open into a bore. A first, second, and third O-rings are located in the bore successively between the feed water port, the squeeze water port, the drain port, and the product water connection. A control piston is moveably located in the bore of the housing. The control piston includes a vent/drain well in which a side is chamfered. The vent/drain well provides a fluid passage between the squeeze water port and the drain port when the vent/drain well passes over the second O-ring. The fluid passage includes an opening formed between the second O-ring and the chamfered side of the vent/drain well, where the size of the opening is responsive to the position of the control piston.

Provided is a water purifier comprising: a filter unit which has a reverse osmosis membrane filter; a supply valve; an instantaneous heating device which is provided with an inflow port, and an outflow port, and which heats and purified water entering through the inflow port and flowing to the outflow port, so that hot water is discharged through the outflow port; an extraction member; a supply pump; a domestic water drain line; a hot water drain line; a hot water drain valve; and a control unit which controls the opening/closing of respective flow channels of the hot water drain line and the domestic water drain line so that, among a hot water draining process through the hot water drain line, and a domestic water draining process through the domestic water drain line, the hot water draining process is carried out first.

Systems and methods for filtering materials from biologic fluids are discussed. Embodiments may be used to filter cerebrospinal fluid (CSF) from a human or animal subject. In an example, CSF is separated into a permeate and retentate using a tangential flow filter. The retentate is filtered again and then returned to the subject with the permeate. During operation of the system, various parameters may be modified, such as flow rate and waste rate.

Algae harvesting and cultivating systems and methods for producing high concentrations of algae product with minimal energy. In an embodiment, a dead-end filtration system and method includes at least one tank and a plurality hollow fiber membranes positioned in the at least one tank. An algae medium is pulled through the hollow fiber membranes such that a retentate and a permeate are produced.

An apparatus for an extracorporeal treatment of blood has a supply line, a waste line, and an ultrafilter inserted in the supply line. An air inlet line is connected to a first chamber of the ultrafilter. A pressure sensor is configured for detecting pressure in the waste line or a second chamber of the ultrafilter. A controller is configured to perform an integrity test procedure for detecting when an ultrafilter membrane of the ultrafilter has multiple or single fiber breaks. A method of testing the ultrafilter is also disclosed.

A control valve for a reverse osmosis water purifying system provides a feed water port, a squeeze water port, a drain port, and a product water connection, each of which open into a bore. A first, second, and third O-rings are located in the bore successively between the feed water port, the squeeze water port, the drain port, and the product water connection. A control piston is moveably located in the bore of the housing. The control piston includes a vent/drain well in which a side is chamfered and at least one recess disposed around an end of the control piston. The vent/drain well provides a fluid passage between the squeeze water port and the drain port when the vent/drain well passes over the second O-ring. The fluid passage includes an opening formed between the second O-ring and the chamfered side of the vent/drain well, where the size of the opening is responsive to the position of the control piston.

Some embodiments of the invention provide a reverse osmosis water filtration system including a housing, a pre-filter cartridge, a reverse osmosis cartridge, and a post treatment cartridge. A medial water line transports a first portion of pretreated water from the pre-filter cartridge to the reverse osmosis cartridge. An unfiltered water line includes a flow restrictor and blend valve. The unfiltered water line is fluidly coupled between the medial water line and a blend water line. The blend water line receives filtered water at a first flowrate from the reverse osmosis cartridge and unfiltered water at a second flowrate from the blend valve. The first flowrate and the second flowrate are substantially equal to produce a consistent total dissolved solids value.

Disclosed techniques include desalination using pressure vessels. Access to a set of at least three pressure vessels is obtained. The pressure vessels are interconnected using piping and computer-controlled switching valves. A first pressure vessel of the set is filled with a prepurified liquid. A second pressure vessel of the set is filled with a pressurized gas. The pressurized gas is sharp interface immiscible with the prepurified liquid. The switching valves are controlled to enable the pressurized gas in the second pressure vessel to force the prepurified liquid from the first pressure vessel into a reverse osmosis chamber. The switching valves are controlled to enable a third pressure vessel of the set to fill with additional prepurified liquid. The switching valves are controlled to enable the pressurized gas that entered the first pressure vessel to force the additional prepurified liquid from the third pressure vessel into the reverse osmosis chamber.

A reverse osmosis prefilter system includes a recirculation chamber for accommodating one or more prefilter cartridges. The recirculation chamber is communicably interconnected to an inline water source and an RO filtration membrane. The recirculation chamber has a recirculation outlet and inlet which are communicably interconnected by an offline pump that recirculates prefiltered water repeatedly through the recirculation chamber and prefilter cartridges to remove particulates from the source water prior to delivery to the reverse osmosis filter membrane.

The present disclosure relates to purification cassettes that have reinforcing features. One embodiment relates to a purification cassette with tensions members. A purification system may include a removable cassette defining a media cavity. A set of tension members may span between a first sidewall and second sidewall. The set of tension members can divide the media cavity into a plurality of lanes.