In one aspect, a modular filter assembly for filtering fluid that flows in a flow direction therethrough is disclosed. The assembly includes a first housing section having a first filter element; a second housing section having a second filter element; and a connector disposed between the first and second housing sections. A housing includes the first housing section, the connector, and the second housing section. The flow direction is through the first and second filter elements in series.

A filter system is provided with a housing provided with a cover. The housing has a raw liquid inlet, a clean liquid outlet, and a liquid drain. A filter element is provided that separates a raw side from a clean side. A slide valve with a valve rod and a sealing head is provided, wherein the sealing head is arranged such that the liquid drain of the housing is closable but openable. A coupling is arranged between the sealing head and the valve rod, providing an axial securing action of the valve rod at the sealing head and a radial securing action, separate from the axial securing action, of the valve rod at the sealing head. A slide valve for such a filter system as well as a sealing head and a valve rod for such a slide valve are provided.

A method including the steps of moving fluid through an inlet into a vessel, the vessel being at atmospheric pressure and having at least one side wall and a bottom wall forming an internal chamber within the vessel. The method further includes moving the fluid into and through a filtration unit utilizing a downstream pump, the filtration unit creating a flux of less than or equal to about 0.05 gallons per minute per square foot (GPM/ft.sup.2), and moving the fluid processed by the filtration unit to an outlet and out of the vessel.

A filter device may include a filter housing and a filter element defining a longitudinal axis disposed in the filter housing. The filter element may be configured to be penetrated by a fluid flow in a radial direction from a raw end to a pure end of the filter element. A water separator may be disposed at the pure end of the filter element and arranged axially spaced from the same. The water separator may have a hydrophobic and annular diaphragm extending in an axial direction of the filter element configured to be penetrated by the fluid flow from a raw end of the water separator in a radially outward to a radially inward direction with respect to the longitudinal axis to separate water from the fluid flow.

A filter device may include a filter housing and a filter element defining a longitudinal axis disposed in the filter housing. The filter element may be configured to be penetrated by a fluid flow in a radial direction from a raw end to a pure end of the filter element. A water separator may be disposed at the pure end of the filter element and arranged axially spaced from the same. The water separator may have a hydrophobic and annular diaphragm extending in an axial direction of the filter element configured to be penetrated by the fluid flow from a raw end of the water separator in a radially outward to a radially inward direction with respect to the longitudinal axis to separate water from the fluid flow.

Defluidizing tanks may include a tank having an interior defined by side walls and a bottom; a filter assembly emplaced within the interior of the tank and constructed to receive a slurry of solids and recovered fluid; and a weir chamber within the tank and defined by the interior of the tank and at least one wall of the filter assembly. Systems may include a source of recovered fluid from a wellbore operation; a filtration unit receiving the recovered fluid and isolating a fraction of solids from the recovered fluid, the filtration unit having a backflush mode in which the fraction of solids is evacuated from the filtration unit; and a defluidizing tank receiving the evacuated fraction of solids to generate a filtrate and dried solids.

A filter device comprising at least one filter element (17) that is exchangeably disposed in a filter housing (1), wherein said filter element (17) is provided on at least one end with an end cap (23) that forms a surround for a rim of a filter material (31), wherein said end cap (23) is provided with a connector (43) with which the filter element (17) may be attached in an operating position to an element seat (19; 45) inside the filter housing (1) in such a way that a fluid-impermeable connection is formed between filter housing (1) and filter element (17), characterised in that the connector (43) enables the positionally fixed mounting of the filter element (17) and the formation of a fluid-impermeable connection in conjunction with element seats (19; 45) of filter housings (1) of different designs.

Systems and methods for filter orientation on a control valve are provided. In particular, systems and methods are provided for rotationally orienting a filter retention feature with respect to an application fluid passageway to control forces and stresses exerted on the filter retention feature. Additionally, methods for manufacturing a control valve are provided that enable a rotational relationship between a filter retention feature and an application fluid passageway to be constrained.

A liquid is made to flow into a filter case from a tangential direction at any point on a side surface of the filter case and produces a swirling flow. Bubbles collected in a center of the swirling flow are retained by a retainer plate, thereby removing the bubbles from the liquid. A filter element filters the liquid from which the bubbles were removed.

A reusable fluid filter system is disclosed. The fluid filter system includes a reusable fluid filter unit that encloses a filter and is removably connected to a manifold. In an embodiment, the filter unit includes an end cap that is detachable so as to replace the filter inside the filter unit. In an embodiment, the filter unit removably engages a valve in the manifold that controls flow paths in the manifold.