Abstract: An emitter for use in drip irrigation comprising an emitter body defining an emitter chamber and a resilient element having first and second opposite faces mounted in the emitter chamber with the first face confronting a surface of the emitter chamber. The surface of the emitter chamber and the first face cooperate to define a restricted fluid passage. The emitter body has an inlet for supplying fluid under pressure to the emitter chamber and an outlet leading from the fluid passage. The resilient element has an aperture providing communication between the second face of the resilient element and the fluid passage so that fluid can pass from the inlet through the aperture and the fluid passage to the outlet. The pressure drop across the aperture is increased to hold the first face of the resilient element against the surface of the emitter chamber to maintain the integrity of the fluid passage.

Abstract: A flow control valve having a valve chamber which is adapted to receive fluid under pressure and which comprises a valve member having a surface with a groove therein and an outlet passage terminating at one end in a port in the groove. A resilient element is provided in the valve chamber in confronting relationship with the groove. The resilient element has an aperture in registry with the groove. The resilient element and the valve member are mounted for relative movement so as to change the relative position of the groove and the aperture, and this permits the manual selection of the flow rate. The pressure in the valve chamber urges the resilient element into the groove an amount which is dependent on the magnitude of the pressure. In this way the selected flow rate is made independent of inlet pressure fluctuations.

Abstract: A flow control valve for use with fluid under pressure comprising a valve body having a valve chamber and a resilient grid in the valve chamber. The valve body includes a control member mounted for rotation and having an interior surface partially defining the valve chamber. The resilient grid includes a transverse wall and a plurality of grid walls extending generally transverse to the transverse wall. The grid defines a plurality of open-ended pockets opening toward, and being closed by, the interior surface. The resilient grid and the interior surface cooperate to define a restricted fluid passage with the grid walls and the interior surface cooperating to define a series of restrictions in the fluid passage. The grid walls are resiliently flexible so that they deflect in response to upstream fluid pressure increases resulting from clogging of one of the restrictions. This makes the valve self-cleaning.

Abstract: A drip irrigation valve comprising an outer member having a passageway and an inner member mounted in the passageway for axial movement. An axially and circumferentially extending rib is provided on a first of the members and cooperates with a confronting surface of a second of the members to provide a helical flow path. Dams are provided in the flow path to increase the resistance to fluid flow. To increase the flow rate, the members are moved axially to take one or more of the restrictions out of the flow passage. To make the valve pressure compensating, one of the member is resilient and can be resiliently deformed by the fluid at inlet pressure to increase the resistance to flow provided by the restrictions.

Abstract: A drip irrigation valve comprising an outer member having a passage, an inner member receivable in the passage, a groove in one of the members, and a seal carried by the other of the members. Water can be admitted to the passage on one side of the seal. The seal cooperates with the groove to define a restricted flow path. The seal is deformable under fluid pressure into the groove to further restrict the flow path thereby making the valve pressure compensating. The groove is tapered or otherwise has regions of different cross sectional areas so that the flow rate through the flow path can be established by the relative axial positions of the inner and outer members.

Abstract: A drip irrigation valve comprising an outer member having a passage, an inner member receivable in the passage, a groove in one of the members, and a seal carried by the other of the members. Water can be admitted through an inlet to the passage on one side of the seal to provide a fluid force on the inner member. The seal cooperates with the groove to define a restricted flow path. A spring urges the inner member in a direction to oppose the fluid force on the inner member. The groove is tapered or otherwise has regions of different cross sectional areas so that the flow rate through the restricted flow path can be established by the relative axial positions of the inner and outer members.