Abstract: A passive, self-regulating valve includes a static pressure chamber and an elastically collapsible tube supported within the static pressure chamber. The elastically collapsible tube is defined by a geometry that determines an activation pressure of the valve. The passive, self-regulating valve also includes a flow restrictor in fluid communication with the elastically collapsible tube inside the static pressure chamber, as well as piping connecting a source of pressurized liquid both to the flow restrictor and to an opening into the static pressure chamber. The piping enables the flow restrictor to control flow rate of the pressurized liquid through the valve independent of the activation pressure of the valve. In a preferred embodiment, the flow restrictor is a needle valve.

Abstract: Self-regulating valve. The valve includes a static pressure chamber with an elastically collapsible tube supported within the static pressure chamber. A flow restrictor is in fluid communication with an inlet into the static pressure chamber for flow through the collapsible tube. Piping connects a source of pressurized liquid, both to the flow restrictor and to an opening into the static pressure chamber, whereby flow rate through the valve remains substantially constant with variations in pressure of the pressurized liquid. In a preferred embodiment, the flow restrictor is a needle valve.

Abstract: A method for manufacturing high speed pressure compensator-type drip irrigation tubes and the tubes obtained thereby having absolute radial orientation of molecular chains, the orientation imparting strength as well as flexibility to the tube material. The said method comprises extruding a tube using a plurality of extruders; blowing up the extruded tube by introducing a pressure inside the tube relatively higher than the pressure outside the tube; drawing the blown tube simultaneously to the blowing of tube; flattening the blown tube by heat welding the collapsed halves together and forming a tape immediately, subsequent to the process of blowing and drawing the tube; extrusion of a bonding polymer on one border of the tape; printing flow channels into the hot and viscous bonding polymer; and forming a tube by lengthwise folding the tape and heat welding the overlapping borders together using the bonding polymer.

Abstract: A method for manufacturing high speed pressure compensator-type drip irrigation tubes and the tubes obtained thereby having absolute radial orientation of molecular chains, the orientation imparting strength as well as flexibility to the tube material. The said method comprises extruding a tube using a plurality of extruders; blowing up the extruded tube by introducing a pressure inside the tube relatively higher than the pressure outside the tube; drawing the blown tube simultaneously to the blowing of tube; flattening the blown tube by heat welding the collapsed halves together and forming a tape immediately, subsequent to the process of blowing and drawing the tube; extrusion of a bonding polymer on one border of the tape; printing flow channels into the hot and viscous bonding polymer; and forming a tube by lengthwise folding the tape and heat welding the overlapping borders together using the bonding polymer.

Abstract: A method for manufacturing high speed pressure compensator-type drip irrigation tubes and the tubes obtained thereby having absolute radial orientation of molecular chains, the orientation imparting strength as well as flexibility to the tube material. The said method comprises extruding a tube using a plurality of extruders; blowing up the extruded tube by introducing a pressure inside the tube relatively higher than the pressure outside the tube; drawing the blown tube simultaneously to the blowing of tube; flattening the blown tube by heat welding the collapsed halves together and forming a tape immediately, subsequent to the process of blowing and drawing the tube; extrusion of a bonding polymer on one border of the tape; printing flow channels into the hot and viscous bonding polymer; and forming a tube by lengthwise folding the tape and heat welding the overlapping borders together using the bonding polymer.

Abstract: The invention describes easily attachable and detachable joints for use in pipe systems carrying pressured fluids. The pipes used for the purpose are made using thermoplastics, preferably polyolefin and provided with integrally formed male spigot end (1) and a female socket end (2). The invention also discloses a method of forming tubes along with their male spigot (1) and the female sockets (2). Joints made using the pipes provided with integral male (1) and female ends (2) are constructed using a push-fit principle. A sealing ring (10) is inserted in the sealing groove (3) of the female socket (2), making the joint leak proof. Plastic or metal clamps (6) are provided to sustain the longitudinal forces imposed on the joint exerted by the pressured fluid. The male spigot (1) is provided with an integrally formed collar (4) that serves as the holding surface to clamp resisting longitudinal forces. The joint is simple in its construction, easy to assemble in field, robust and cost effective.

Abstract: A novel locking pipe joint for use in fluid-carrying pipe systems is described. The locking pipe joint of the present invention provides a system of joints that will withstand the stresses and forces imposed on a pipe system carrying fluids. The joint is constructed on a push-fit principle. Sealing rings are used to make the joint leak-proof. Splines are provided to sustain the longitudinal forces imposed on the joint, and longitudinal ribs are provided on the outer surface of the joined pipes to withstand the torsional loads. The joint is simple in its construction, easy to assemble in field and cost effective.