NZ211707A - Pressure regulating valve for trickle irrigator - Google Patents

Description

1 7 Priority Date(s): i ?iU Complete Specification Filed: Class: J&K.QJ. y.Q.Q./.. ftQf*. DJ& &Q.& 3§/.(<?. p lii' "'"'' "ff '"J0N1986 Publication Date: P.O. Journal, No: ..as.o. | m. rATEKTOFRCfc o p t^r: 5\/\" n Patents Form no: 5.

PATENTS ACT 1953 COMPLETE SPECIFICATION "DEVICE FOR THE CONNECTION OF A WATERING SYSTEM" WE, GARDENA KRESS + KASTNER GmbH, Lichternseestrasse 40, Postfach 27 47 D-7900 Ulm / Donau, Federal Republic of Germany a company organised and existing under the laws of the Federal Republic of Germany, hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- ^ - J 811707 DEVICE FOR THE CONNECTION OF A WATERING SYSTEM The invention relates to a connector device for watering systems, preferably with numerous watering points, particularly drip watering outlets, with one inlet and one 5 outlet.

Drip watering, in which water is supplied directly to the soil, preferably in the immediate vicinity of individual plants and without spraying into the air by means of sprinkler systems, has the advantage that a much smaller proportion of 10 the water is directly evaporated and consequently the usable proportion of the water absorbed by the plant is much greater. The salinization risk of continuously watered soil is also greatly reduced. However, in drip watering, the metering and keeping clean of the drip watering outlet constitute a 15 problem, because in this case relatively small quantities have to be reliably dosed over a long period. Such drip watering systems are particularly advantageous in areas with high ambient temperatures and low atmospheric humidity, where the water supply is problemmatical. Therefore, very 20 considerable pressure fluctuations must be expected in the water supply. Problems are also caused by the lengthy and branched hose or pipe system in this watering mode.

Such drip watering systems and their watering outlets are known from U.S.Patents 3,727,635 granted on 17.4.1973 25 and 3,841,349 granted on 15.10.1974 to T.J. Todd, reference being made thereto for the purposes of the present description.

The problem of the present invention is to provide a device,- which simplifies the dosing and piping problems 30 in the watering systems.

This problem is solved by the, present invention, which pro- L. B. Si A. i vides a device for connecting a wsfee^system to a pipe for press- - urized water, the a r>1 n-ral-i t-v of v;atering outlets, , jt, . each of which has.only a very low water flow rate, the device I forming a unit containing a pressure-tight casing with an inlet correctable to the pipe and an outlet connectable to the watering system, a pressure regulating valve being arranged in the flow direction upstream of the outlet in the casing and regulates a pressure at the outlet which is substantially independent of the pressure in the pipe and the unit contains a filter in the flow direction upstream of the pressure regulating valve and a check valve blocking a return flow from the casing to the inlet.

This gives an easily transportable, compact unit, in which the check valve prevents return flows to the water main. The filter not only protects the pressure regulating valve, but also the watering system with the dirt-sensitive watering outlets against blockages. 10 As aresult of the pressure regulating valve, at each watering point of the watering system, the same pressure prevails and therefore, independently of the pressure of the water supply system (water main or pump), there is a substantially constant discharge. The water main is also protected against 15 overpressures, so that hosepipes having a moderate pressure resistance can be used and are connected by simple fit-in or on fixtures.

The pressure regulating valve is preferably constructed for regulating a substantially constant discharge pressure 20 for the Same flow rate and has a compensating means for increasing the discharge pressure when the flow rate is increased. Thus, the pressure regulating valve in each case regulates a pressure in the watering system, which rises somewhat with increasing flow rate. This counteracts 25 the increased pressure losses occurring with the increased flow rate. Therefore,the connector device can be very universally used and automatically adapts to the given conditions, particularly the size and branched nature of the. watering system, without any manual regulating measures 30 being necessary.

-I ij J ^ 4 - The compensating means preferably contains a branch to the flowing medium and in particular a Venturi tube. Thus, the pressure drop produced by the flowing medium is used for regulating the compensation. 5 According to a preferred embodiment, the pressure regulating valve can have a pressure chamber, adjacent to which there is a diaphragm which moves a valve body and subject to pressure action on the outlet side only. The pressure chamber can be connected via the branch, which is 10 preferably constructed as a ring nozzle, to an outlet side flow duct. The pressure drop in the flowing medium consequently reduces the pressure acting in the diaphragm and therefore brings about the desired compensation, i.e. pressure rise for increased flow rate. 15 A particularly simple and operationally reliable construction of the pressure regulating valve is obtained if the spring-loaded diaphragm centrally surrounds the hollow valve body, which is guided in an axially movable and sealed manner in the connector device casing and 20 surrounds a portion of the discharge flow duct. The branch can be constructed in the gap between the flow duct portion belonging to the valve body and the following flow duct portion in the casing. This construction is very space-saving and there is no risk of it tilting as a result of 25 its constructional and force-based symmetry.

The device casing can contain reception means for water-soluble active components, which are preferably constructed in such a way that into the filter, which is constructed as an insert, projects a projection provided 30 with lateral water outlets and through which water axially at 17 07 flows and which serves to receive annular, water-soluble active component tablets. Thus, the connector device fulfils a third function, namely that of an admixing device for soluble fertilizers or other water admixtures.

As a result of the annular shape, it is not only possible to easily store the tablets within the cup-shaped filter, but most of their surface area is also exposed to the liquid. The annular shape also ensures that the admixture remains relatively constant, although the size and shape 10 of the tablets change during their dissolving. As dissolving advances, not only is there a reduction in the outer surface of the annular or hollow cylindrical tablet due to a diameter decrease, but the inner surface is increased through a diameter increase of the inner circumference, 15 so that an automatic compensation occurs. As a function of the nature and shape of the projection and the water passage in the filter housing, it can be established how the active component wearing away will really take place. If the flow is guided in such a way that there is a planned flow 20 round both the inner surface and the outer surface, then the most uniform wearing away takes place. However, it is vital that the flow is guided through the interior of the possibly multiple stacked tablets forming an elongated V hollow cylinder, because there is normally no natural flow 2 5 there, as is the case on the outer circumference as a result of turbulence etc.

The projection can be centrally provided on an unscrewable insert belonging to a frontal cover and on it is also centrally arranged the inlet. This arrangement, 30 particularly together with the central arrangement of the pressure regulating valve with respect to the longitudinal axis of a cylindrical casing, leads to a particularly simple constructional shape as a cylinder, whose inlet and outlet side cover is in each case unscrewable and 5 contains the individual functional parts. The inlet port can contain a check valve, which more particularly prevents any return to the mains of the active component-enriched water.

The features of the invention and their preferred 10 further developments, as can be gathered from the claims and description in conjunction with the drawings, can be essential to the invention either singly or in random subcombinations .

An embodiment of the invention is shown in the drawing. 15 Fig 1 shows a longitudinal section through the device. Fig 2 shows a diagrammatic view of a watering system.

Fig 2 shows a watering system 60, which comprises a branched network of pipes or hoses 61 having different diameters, which are interconnected by means of branch 20 pieces 62 and on whose ends are arranged watering outlets 63, also called drippers, which discharge very small quantities of water, virtually in the form of individual drips or drops. The watering system is connected via a hose 64 to the outlet of a device 11, which will be described in 25 greater detail hereinafter. The device inlet is connected via a hose coupling 65 and a hose 66 to a water main 67.

Device 11 will be described hereinafter relative to Fig 1.

The connector device 11 has an inlet 12 in the form of a plug-in connection nipple for a high-speed hose coupling 30 and an outlet in the form of a hose nipple, on which can be fitted a flexible hose and is secured there by barb-like ribs. The connector device is connected by its inlet, either via a hose or directly to a water supply system, whilst a drip watering system is preferably connected to 5 the outlet. It comprises a normally extensively branched system of hoses which, in one or more main strands, have a diameter corresponding to the outlet dimensions and pass to a smaller diameter towards the individual watering points. The watering points contain drip watering outlets, which 10 only discharge a very small water quantity per unit of time.

They can be of a conventional construction and can be provided with labyrinth packings or other flow ducts with a small cross-section for restricting the water flow.

Connector device 11 has a cylindrical, pressure-tight 15 plasticrcasing 14 provided on the outside with annular ribs •> and which has feet 15 on the bottom. At both ends, it is closed by inlet and outlet side covers 16, 17, which can be screwed in the manner of a cap nut onto the casing ends which have an external thread. In the case of inlet cover 16 20 the cap nut 18 is separately provided by a cover insert 19, which has a central connecting piece 21, which is therefore concentric to the device - longitudinal axis 20 and onto which is screwed the plug-in connection nipple. A check valve 22 is inserted in the connecting piece and comprises 25 a spoked wheel-like valve seat plate and a cross-sectionally lamda-shaped, flexible plastic valve body, whose portions s which slope towards the centre cover the openings between the spokes of the valve body. The outer circumference is sealed on the inner wall of the connecting piece and an 30 axially inwardly sloping wall portion engages on the outer 2 I I 7 0 wall of the connecting piece and at this point closes a vent hole 23 leading to the open.

The central, axially directed feed pipe 24 terminates on the cover insert with a connection 25 projecting into 5 the interior of casing 14 and in which is inserted a projection 26 in the form of an elongated profile, which extends over most of the casing, which is shown in broken away form in the drawing, but which is in practice much longer. The projection is cross-sectionally cross-shaped 1 0 and on two facing sides is provided with in each case transversely directed portions. This leads to the formation of four parallel channels 27, which are open to the outside, which carry the water, but which also issue laterally.

The circumference of cover insert 19 is sealed with 15 respect to the casing, by a sealing ring and secures a filter insert 28, which is inserted in the casing provided with longitudinally directed ribs 29 for spacing and twisting protection purposes. The filter insert is cup-shaped and is made from an injected plastic moulding with 20 a ring 30 surrounding the mouth and a closed bottom 41, which are interconnected by webs 32. The window-like cutouts formed between the webs are covered by a filter screen 33, which is connected to the aforementioned plastic insert by moulding in or welding. The filter screen comprises a very 25 fine-mesh fabric of monofilament plastic threads.

Circular or annular active component tablets 34 are inserted in the annular space formed between the projection and the interior of the filter insert and they are indicated in broken line manner. They are lined up on 30 the projection 26, which is constructed as a longitudinally 211707 profiled bar and together with the channels 27 form a flow duct, through which the water flows, before it passes through filter screen 23 into the casing.

The bottom 31 of filter insert 28 is supported on 5 a central valve seat part 35 of the casing, which projects from a casing wall 37 terminating the filter chamber 36. Concentrically to axis 20, wall 37 carries a cylindrical connection 38 directed towards the outlet side and which is arranged in an extension of the valve seat part 35. The 10 latter is carried by lateral webs 39 and has a toroidally concavely curved valve seat face 40, which faces the inside of connection 38. The outer circumference of a diaphragm 41 belonging to a pressure regulating valve 42 is secured between the outlet side cover 17 and the casing end face. 15 The diaphragm, which is provided with an expansion crease, is centrally connected to a hollow valve body 43, which is fitted there in the manner of a hub and has a hollow cylindrical part 44 projecting towards the inlet side and whose end forms the movable valve seat and is provided 20 there with an elastic, annular valve seat cap 45. In the interior of connection 38, part 44 is sealed in an axially L B & A movable manner by a sealing ring 46.

A spring 49 loads the valve body in the direction of P/ the outlet side cover 17, where it fits by projections 47 2 5 in the inoperative state.

An annular pressure chamber 48 is formed between cover 17 and the flexible plastic or rubber diaphragm 41 and is connected by means of a branch 50 to the outlet side, central flow duct, which comprises two aligned portions, 30 which are central with respect to the longitudinal axis 20, 117 0 7 namely the flow duct portion 51 in the interior of the hollow valve body 53 and the portion 52 formed in the interior of the outlet nipple 13, i.e. cover 17. An annular gap is formed between the two portions and is dimensioned 5 in such a way that it is still present in the represented inoperative state of the valve body and together with a cylindrical ring portion forms branch 50, which leads into pressure chamber 48. Gap 53 changes its width there with the position of the valve body. In the vicinity thereof, 10 portions 51 and 52 of the outlet side flow duct taper in nozzle-like manner and are then widened again, so that they form a Venturi tube.

The connector device functions as follows. After being connected on the outlet side to a watering system, 15 it can be connected via its inlet 12 to a water main, pump or the like. The water flows in via check valve 22 and raises the inwardly sloping ring seal portion. It then flows via connecting piece 25 into channels 27 and then, if active component tablets 34 are inserted, through the 20 flow duct formed in the interior thereof, from which it issues upstream of bottom 31 and now, enriched with the dissolved active component, overflows through filter screen 33 into filter chamber 36. The wearing away of the active component tablets, e.g. fertilizer tablets, takes place both 2 5 from the inside and from the outside, because a turbulent flow forms in the area round the tablets. The water then flows through the valve port 54, constructed in the manner of a turbine inlet, into the outlet side flow duct 51, 52. As there is a counterpressure on the outlet side as a 30 result of the connected watering system, this is propagated I 1 70 7 via branch 50 into pressure chamber 40 and acts on the diaphragm, on whose other side there is atmospheric pressure as a result of the venting of the corresponding casing area 55. The pressure chamber pressure acts on the 5 differential surface between the total membrane surface and the sealing surface of the valve body and moves the diaphragm and consequently the valve body 43 towards the valve seat surface 40, so that the water flow is restricted between the latter and cap 45.

The liquid flowing through flow duct 51, 52, assisted by the Venturi tube-like constriction, produces on annular clearance 53 a pressure reduction compared with the static pressure on the outlet side, which acts on the pressure chamber 48 and consequently brings about a reduced diaphragm 15 deflection and a higher flow rate. By corresponding dimensioning of the flow duct and the diaphragm an equilibrium can be produced as a result thereof, whereby a particular outlet side pressure is associated with a particular flow rate. This pressure rise compensates the flow losses occurring 20 in the watering system when there is a higher flow rate and ensures that there is a constant pressure at the individual watering points. This is particularly advantageous for drip watering, but can also be important for other watering means, e.g. sprinklers,for which the present connector device can 2 5 also be provided. Thus, a pressure is produced, which is dependent on the aforementioned conditions and is constant independently of the pressure on the inlet side, so that the outlet side system need only be designed fir a specific maximum pressure.

Check valve 22 ensures that no liquid can flow back 2f j 70 from the interior of the connector device via the inlet, e.g. as a result of a vacuum on the inlet side. Even if there was a leak in the check valve, the sleeve would free the vent hole 23, so that the vacuum would 5 be removed. 211707

Claims (14)

1. WHAT WE CLAIM IS:- p. l. b. & a. \ lesi "<)
2. K-dJ^j 1. A device for connecting a water^system to a pipe P?'" G>~( &IV-. for pressurized water, the watering^having a plurality of watering outlets, each of which has only a very low 5 water flow rate, the device forming a unit containing a pressure-tight casing with an inlet connectable to the pipe and an outlet connectable to the watering system, a pressure regulating valve being arranged in the flow direction upstream of the outlet in the casing and 10 regulates a pressure at the outlet which is substantially independent of the pressure in the pipe and the unit contains a filter in the flow direction upstream of the pressure regulating valve and a check valve blocking a return flow from the casing to the inlet. 15 2. A device according to claim 1, in which the pressure regulating valve is constructed for regulating a substantially constant outlet pressure for the same flow rate and a compensating means is provided for increasing the outlet pressure in the case of an increased flow rate. 20
3. 3. A device according to claim 2, in which the compensation means contains a branch to a.discharge flow duct.
4. 4. A device according to claim 3 in which the compensating means contains a pressure reducing device functioning in Venturi tube-like manner. 25 5. A device according to claim 4 in which the pressure regulating valve has a pressure chamber, adjacent to which ; -9 APR 1986 MM 211707 - 14 - there is a diaphragm moving a valve body and subject to pressure action on the outlet side only, the pressure chamber being connected via the branch to an outlet side flow duct.
5. 5
6. 6. A device according to claim 5 in which the branch is constructed as an annular clearance.
7. 7. A device according to claim 5, in which the spring-loaded diaphragm centrally surrounds the hollow valve body, which is guided in axially movable and sealed manner 10 in the device casing and surrounds a discharge flow duct portion, the branch being formed in the gap between a flow duct portion belonging to the valve body and a following flow duct portion in the casing cover.
8. 8. A device according to claim 1, in which the filter is 1 5 an insert fittable to the casing in the form of a cylindrical cage, whose surfaces at least partly comprise a screen material, the surfaces running approximately parallel with the surfaces of the cylindrical casing, the . filter insert enclosing a space taking up most of an 2 0 inner area formed in the casing.
9. 9. A device according to claim 1, in which reception means for water-soluble active components are provided upstream of the filter in the casing.
10. 10. A device according to claims 8 and 9, in which the 25 receiving means contain a projection projecting into the » 5 P- L. B. & A. 8/M./St 211707 - 15 - area of the filter insert, which is provided with lateral water outlets and through which the water axially flows, it being constructed in the form of at least one circular, water-soluble tablet for receiving the active component, a flow channel being formed within the tablet.
11. 11. A device according to claim 10, in which the projection is provided centrally on an unscrewable insert belonging to the frontal ctver of the casing and on which is also centrally arranged the insert.
12. 12. A device according to claim 1, in which the check valve is provided in an inlet side flow duct.
13. 13. A device according to claim 12, in which the check valve is connected to a vent hole.
14. 14. A device for connecting a watei^system to a pipe for pressurized water, substantially as hereinbefore described with reference to and as shown in the accompanying drawings. N.z. PAT"'Civ--" i/ J'.i GARDENA KRESS + KASTNER GmbH by their authorised agents P.L. BERRY & ASSOCIATES Rb'€£.yfoJ j per