Constant-flow irrigation tape and method of making

摘要

A constant-flow drip irrigation tape hose includes a primary flow path (34) communicating water along the length of the hose (18). A secondary drip-flow path (36) leads from the primary flow path (34) to an emitter site outwardly of the hose (18). The hose (18) is formed with a pair of variably spaced apart walls (38,40) at least one of which is formed with a continuously-open channel (52) defining part of the secondary flow path (36). A second variable-area part of the secondary flow path is defined by radial spacing of the pair of walls (38,40) from one another. At least one of the pair of walls (38,40) is responsive to internal water pressure in the primary flow path (34) to open and close the variable-area part of the secondary flow path (36) in response, respectively, to decreasing and increasing water pressure in the hose (18). A plurality of emitter sites (22) are spaced regularly along a length of the hose (18). Consequently, the hose (18) has at least one pressure range within which it provides a nearly constant drip-flow irrigation rate to plants of a row crop as the water pressure within the hose (18) decreases over the length of an elongate run of hose (18). <IMAGE>