Drip irrigation control device - comprises pipe with ports enclosed by sheath which is expanded by internal liquid pressure

摘要

The irrigation control comprises a length of pipe (2) with one or more liquid discharge ports (4), together with an elastic and extensible sheath (6) enclosing part at least of the pipe and covering the ports. The sheath has one or more end sections (7) expanding in response to the pressure of liquid in the pipe, and regulating the rate at which the liquid flows out between the external surface of the pipe and the internal one of the expandible sheath and section. The sheath can be arranged to fit closely round the pipe, and can have one or more ports formed by cutting out part of it, and through which the liquid also emerges.