GB2187622A

GB2187622A - Irrigation system

Info

Publication number: GB2187622A
Application number: GB08605855A
Authority: GB
Inventors: Eric Miller
Original assignee: WIMPEY LAB Ltd
Current assignee: WIMPEY LAB Ltd
Priority date: 1986-03-10
Filing date: 1986-03-10
Publication date: 1987-09-16
Anticipated expiration: 2006-03-10
Also published as: GB2187622B; GB8605855D0

Abstract

An irrigation system comprises a manifold (15) which, when unpressurised, is substantially flat and which, when pressurised by a relatively low pressure water supply (10), has a substantially circular cross-section. The manifold is connected to the water supply. A plurality of irrigation pipes (15a, 15b, 15c) are connected at spaced apart points along the length of the manifold pipe. <IMAGE>

Description

SPECIFICATION Irrigation system This invention relates to irrigation systems.

Although the present invention is primarily directed to any novel integer or step, or combination of integers or steps, herein disclosed and/or as shown in the accompanying drawings, nevertheless, according to one particular aspect of the present invention to which, however, the invention is in no way restricted, there is provided, an irrigation system comprising: a manifold pipe which when unpressurised is substantially flat and which when pressu rised by a relatively low pressure water supply has a substantially circular cross-section; means for connecting the manifold to the water supply; and connecting means for connecting a plurality of irrigation pipes at spaced apart points along the length of the manifold pipe.

The manifold pipe may be made of multi-layered plastics material.

Preferablytheconnecting means comprises a pluralityofstub pipes connected to the manifold pipe. Each stub pipe may be welded into a respective aperture in the manifold pipe. Alternatively, each stub pipe may be formed integ rally with the manifold pipe.

In another embodiment the connecting means comprises a plurality of rigid or semi-rigid connector members each secured in a respective aperture in the manifold pipe. Each connector member may be welded to the manifold pipe.

According to another non-restrictive aspect ofthe present invention there is provided an irrigation system as above in combination with a plurality of irrigation pipes. The manifold may be connected to a water storagetankas the source of water.

The invention is illustrated, merely byway of example, in the accompanying drawings, inwhich: Figure lisa schematic perspective view of an embodiment of an irrigation system according to the present invention; Figure2A shows one embodiment of a manifold pipe of the irrigation system of Figure 1 when unpressurised; Figure2B shows the manifold pipe of Figure 2A when pressurised; Figure 3 shows another embodiment of a manifold pipe of the irrigation system of Figure 1 when unpressurised; Figure4shows connectors for connecting a manifold pipe ofthe irrigation system of Figure 1 to irrigation pipes; and Figure 5illustrates the connection of a manifold pipe ofthe irrigation system of Figure 1 to a main pipe.

Referring first to Figure 1 there is illustrated one embodiment of an irrigation system according to the present invention. The irrigation system comprises a water storage tank 10 which is connected to receive a watersupplyfrom an inlet pipe 11 Water may be pumped through the pipe 11 by any conventional means such as a solar powered pump (not shown). A valve 12 is disposed at the outlet of the tank 10 and immediately downstream of the valve there is a filter 13. The outlet side of the filter is connected to a main pipe 14which in turn is connected to a manifold pipe 15. Extending laterally from the pipe 15 are a plurality of irrigation pipes 1 5a, 1 5b, 1 5c. The end of the pipe 15 is closed by a closure connector 17.

The irrigation pipes 15a are so-called seep laterals, that is they lie on the surface of the ground between rows of plants to be irrigated. The seep laterals have small holes along their length to allowwaterto escape therefrom to irrigate the adjacent plants. The irrigation pipes 1 5b are so-called sub-surface laterals which are rigid or semi-rigid pipes with apertures along their length. These sub-surface laterals are laid below the surface of the ground and water escaping therefrom irrigates a crop, e.g. wheat or maize, being grown above the sub-surface laterals. The irrigation pipes 1 sic have emitters 16 which provide irrigation at discrete points along their length.The emitters 16 may be located around trees, for example, and are adjustable so that the amount of water supplied to each tree can be predetermined. Each emitter 16 may, for example, be a microbore plastics tu be, whose length can be adjusted to give the required flowofwaterfrom its free end.

The pipes 14, 15 are each of relatively large diameter, e.g. 1 00mm and of relative thin, e.g.

0.2mm, flexible material which is tough, tear-proof and not degraded by ultra-violet radiation. The pipes 14, 15will lieflatwhen unpressurised and inflate two substantially circular cross-section when filled with water under relatively low pressure. For example for a water pressure within the pipe more than three times the equivalent pipe diameter (e.g. a pressure of morethan300mm of waterfor a pipe having a diameter of 1 OOmm) the cross-section ofthe pipe is substantially circularwith an area in excess of 99% of that of a true circle.

The pipes 14,15 are preferably made of multi-layered polyethylene formed into atough durable sheet which is over-lap welded, edge welded or otherwise formed into a pipe. Figure 2A shows one embodiment of the pipe 15 when unpressurised.

The pipe has an over-lap welded seam 20 and lateral stub pipes 21 made ofthe same material as the pipe 15. The stub pipes are welded into respective apertures formed in the pipe 15. Figure 2B shows the pipe 15 when pressurised and also shows one of the stub pipes 21 connected to one of the irrigation pipes 15a by inserting a rigid cylindrical connector22 into the free end of each stub pipe 21 and into one end of the irrigation pipe 15a. The connector 22 is maintained in place by clips 23 one of which sandwiches the end of the irrigation pipe 15a between itself and the connector 22 and the other of which sandwiches the free end of the stub pipe 21 between itself and the connector 22. The other irrigation pipes 15a, 15b, are connected to respective stub pipes 21 in the same manner.

Figure 3 shows another embodiment of the pipe 15 in which two sheets of plastics material are welded together at their lateral edges 24 so that the pipe 15 and the stub pipes 21 are integrallyformed. The stub pipes 21 are connected to the irrigation pipes 15a, 15b, 15e in the same manner as illustrated in Figure 2B. As manufactured,the stub pipes may be sealed at thei r ends remote from the pipe 1 5 so al lowing the installerto select at will those stub pipes to be used in a particular irrigation configuration. Moreover,the stub pipes may be tapered, for example with a diameter of 20mm adjacenttothe pipe 15 and a diameter of 16mm attheirfree ends.This enables the installerthe choiceoftvso diameters of irrigation pipe 1 5a, 1 5b, 1 5e to connect to the stub pipe.

The forms of pipe 1 shown in Figures 2a and 3 have the advantages that they can be tightly rolled upforshipmentandforstoragewhen not required but yet have a substantially circular cross-section when pressurised.

Figure 4 shows a cross-section ofthe pipe 1 with two forms of rigid or semi-rigid connector 25,30 for connecting the pipe to the irrigation pipes 1 Sa, 1 Sb, 15c. The connector 25 has a cylindrical portion 26 which projectsthrough an aperture in the pipe 15 and a nut 27 is screw-threaded onto the portion 26 so thatthe material ofthe pipe surrounding the aperture is sealinglytrapped between the nut 27 and a flange 28 ofthe connector 25 located within the pipe 15. This form of connector can be fitted to the pipe 15 bythe installer of the irrigation system.The aperture would beformed in situ in the pipe 15 adjacent the desired location ofthe irrigation pipe 15a, and l5candtheconnectorwouldthen befitted in the aperture. It will be appreciated that the nut 27 could be replaced buy a conventional wedge fitting if desired. To connect the connector25to one ofthe irrigation pipes 15a, 15b, 1Scthe portion 26 is inserted into the interior of the irrigation pipe and retained by means of a conventional pipe clip (not shown).

The connector 30 has a cylindrical portion 31 passing through an aperture in the pipe 15 and a flange 32 disposed internallyofthe pipe and welded thereto. This forum of connector would be installed when forming the pipe 15 in a manufacturing plant.

One ofthe irrigation pipes 15a, 15b, 1Scis connected to the connector 30 in the same manner as the connector 25.

Figure 5 shows one ofthe irrigation pipes 1 5a connected to one ofthe connectors 25,30 by means of a conventional clip 34. Figure 5 also shows a rigid connector 35 inserted into one end ofthe pipe 15 and sealingly retained by a plastics strap 36. The connector 35 is also inserted into one end of pipe 14 and similarly retained by a plastics strap (not shown). Inthis mannerthe pipes 14, 15 are connected together in a watertight manner.

It will be appreciated that in addition to the filter 13 the storage tank 10 could have an internal filter (not shown) through which water passes to the outlet of the tankandthe valve 12.

The irrigation system described above is designated to operate under gravity flow from a concrete storage tank 10 providing a relatively low pressure water supply, e.g. with a pressure of 2m of water. The area to be irrigated is preferablyflat falling away gently from the tank 10. The relatively large diameterflexible pipes 14, 15 reduce pressure losses in the irrigation system. Thus a pumped water supply is unnecessary so that the irrigation system may be used in areas, such as third world countries, where there is no inexpensive power supplyto operate pumping apparatus.

Claims

1. An irrigation system comprising: a manifold pipe which when unpressurised is substantially flat and which when pressurised buy a relatively low pressure water supply has a substantially circular cross-section; means for connecting the manifold to the water supply; and connecting means for connecting a plurality of irrigation pipes at spaced apart points along the length ofthe manifold pipe.

2. An irrigation system as claimed in claim 1 in which the manifold pipe is made of multi-layered plastics material.

3. An irrigation system as claimed in claim 1 or2 in which the connecting means comprises a plurality of stub pipes connected to the manifold pipe.

4. An irrigation system as claimed in claim 3 in which each stub pipe is welded into a respective aperture in the manifold pipe.

5. An irrigation system as claimed in claim 3 in which each stub pipe is formed integrally with the manifold pipe.

6. An irrigation system as claimed in claim 1 or2 in which the connecting means comprises a plurality of rigid orsemi-rigid connector members each secured in a respective aperture in the manifold pipe.

7. An irrigation system as claimed in claim 6 in which each connector member iswelded to the manifold pipe.

8. An irrigation system as claimed in any preceding claim in combination with a plurality of irrigation pipes.

9. An irrigation system as claimed in claim 8 in which the manifold is connected to a water storage tank as the source of water.

10. An irrigation system substantially as herein described with reference to and as shown in the accompanying drawings.

11. Any novel integer or step or combination of integers or steps, hereinbefore describedand/oras shown in the accompanying drawings, irrespective of whether the present claim is within the scope of, or relates to the same or a different invention from that of, the preceding claims.