Abstract: A multi-element filter unit includes backwash apparatus and comprises a filter casing with provision for alternative, oppositely directed process liquid and backwash liquid flows therethrough. A plurality of filter tubes are close spaced within the filter casing. A flange engages the filter tubes and divides the filter casing into first and second chambers. Apparatus for sequentially backwashing the filter tubes during a backwash interval removes collected solids from between the filter tubes by flow of backwash liquid from one filter tube outward toward the exterior of adjacent filter tubes.

Abstract: A self-cleaning filter assembly for removing solids from an incoming liquid to be filtered. A filter element is fixed substantially coaxially within a housing and spaced from the peripheral wall thereof by an annular solids collection space in turn communicating with a solids outlet. An inlet introduces pressurized liquid to be filtered circumferentially into the solids collection space. A shower assembly rotates coaxially within the filter element and includes an eccentric portion having jets distributed along the length of the filter element and aimed outward close to the inner surface of the filter element. Backwash liquid enters the rotating shower assembly under pressure for continuously pushing solids off the outer surface of the filter element as the shower assembly circumferentially advances in the housing. Filtrate from inside the filter element passes through a filtrate outlet extending from the housing.

Abstract: A narrow pressure sensor unit interposable between close spaced flanges on coaxially opposed pipes. The pressure sensor unit includes an annular body sandwiched coaxially between two flanking rings of lesser inside diameter by a circumferential array of axial fasteners. A resilient cylinder has an intermediate portion spaced radially inward of the annular body by an annular sensing fluid chamber. The cylinder is of generally U-shaped cross section and has sides extending radially outward along annular reliefs in the flanking disks. Axially widened lips on such sides lie in opposed annular grooves in the flanking rings, and are compressed between the axially opposed surfaces of the respective flanking ring groove and body to seal the fluid chamber. The lips are radially wider than the axial width of the reliefs to lock the lips in the grooves. A pressure gauge connects through the body to the sensing fluid chamber.