US3794248A

US3794248A - Valve construction for irrigation systems

Info

Publication number: US3794248A
Application number: US00353589A
Authority: US
Inventors: R Sherman
Original assignee: Lockwood Corp
Current assignee: Lockwood Corp
Priority date: 1973-04-23
Filing date: 1973-04-23
Publication date: 1974-02-26
Anticipated expiration: 1991-02-26
Also published as: CA995557A

Abstract

A valve construction for use in irrigation systems or other systems wherein liquid is moved through lines from one position to another. The valve is particularly utilized in a system wherein spray heads are connected to the lines with the liquid being passed through the spray heads for distribution over a relatively large area. The construction includes a valve seat located in a passage used for delivering liquid to a spray head. A valve for engaging the seat and for cutting off the flow of liquid through the passage is employed. The construction defines a cavity reciprocally receiving the valve and resilient means supported in the cavity normally urge the valve toward the valve seat. The pressure developed by the liquid source of the system will unseat the valve under normal conditions, and due to the back pressure developed because of the restriction provided by the spray head, the valve will remain in this condition during operation. The cavity receiving the valve is vented to the atmosphere, and when the pump or other means for supplying the liquid is removed, the valve will automatically close. The vent passage may be connected to a conduit which provides an alternative source of liquid pressure for controlling the valve operation independently of the automatic control otherwise provided.

Description

[ 111 3,794,248 [451 Feb. 26, 1974 VALVE CONSTRUCTION FOR IRRIGATION [57] ABSTRACT A valve construction for use in irrigation systems or SYSTEMS Inventor:

Roger M. Sherman, Los Gatos, Calif.

Assignee: Lockwood Corporation, Gering,

other systems wherein liquid is moved through lines from one position to anotherrThe valve is particularly N b utilized in a system wherein spray heads are connected e t0 the lines with the liquid being passed through the Apr. 23, spray heads for distribution over a relatively large [22] Filed:

[211 Appl. No.: 353,589

area. The construction includes a valve seat located in a passage used for delivering liquid to a spray head. A valve for engaging the seat and for cutting off the flow of liquid through the passage is employed. The construction defines a cavity reciprocally receiving the valve and resilient means supported in the cavity normally urge the valve toward the valve seat. The pres- 00 9 75 6 5 w o. 2 5 7 0 7 9 n m? a 3 3 2 3 9"6 a "7w 5 n ,3 32 w "9 2 "3 I In c .r "8 "a L C kw mh UIF 1111] 2 8 555 [.11.

- suredeveloped by the liquidsource of the system will References Cited UNITED STATES PATENTS 11/1924 unseat the valve under normal conditions, and due to the back pressure developed because of the restriction 239/533 X Provided by the spray .head, the valve will remain in 239/533 X this condition during operation. The cavity receiving 239/96 7 the valve is vented to the atmosphere, and when the 239 570 x pump or other means for supplying the liquid is re- 239/533 X moved, the valve will automatically close. The vent passage may be connected'to a conduit which pro- Dunkelberger Mashinter et a1.

S N w A m w ML WP P A MR .1 a

Sun-W A P N m E R O F 062 5/1970 Waldman............. 355 12/1970 vides an alternative source of liquid pressure for con- 9l6,587 1/1963 GreatBritain...................... 239/57Q trolling h valve operation independently of the auto matic control otherwise provided.

Prim ary Examiner-Robert S. Ward, Jr. v

10 Claims, 6 Drawing Figures Attorney, Agent, or Firm-M cDougal1,- Hersh & Scott Pmmmrzazslm SHEET 2 OF 2 :5 wmf I+ N Q JUNK &

VALVE CONSTRUCTION FOR IRRIGATION SYSTEMS This invention relates to an irrigation system or the like. The invention is particularly directed to systems wherein liquid is moved through lines and is distributed over a desired area by means of spray heads connected to the lines.

In sprinkler systems of the so-called underground or solid-set" type, problems often develop because of the sprinkler head arrangements employed. Particularly in large systems, ittakes time for the water pressure to build up to proper operating levels, and this can lead to excess water distribution in localized areas causing erosion and other problems. This undesirable Operation can go on for several minutes until the system is filled with water and comes up to pressure.

Mobile irrigation constructions have also been developed for delivering water, liquid fertilizer, etc., over large areas thereby eliminating the manpower other wise necessary for accomplishing such tasks. The mobile systems may comprise self-propelled sprinkler systems wherein a central source of water is delivered through lines with the lines being supported on driven structures and with sprinkler-heads being located in the lines for delivering the water.

In a typical system, a main distributor pipe as much as one-half mile in length may be utilized. The inner end of the pipe is connected to a source of water whereby the water can be delivered under pressure to sprinkler heads spaced along-the length 'of the pipe. Various mechanisms are available for moving the distributor pipe with a typical systeminvolving rotational movement of the pipe about'acentral pivot with the water supply being located at the pivot point. The pipe may be supported ona plurality of independently driven supporting towers located at spaced intervals along the length of the pipe.

In view of the size of the systems involved, the distribution of water or other liquid can create certain problems similar to the problems referred to with respect to stationary systems. For example, the system may be utilized on uneven terrainin which case, the sprinkler heads will bevmoving up and down during operation of the system. When the system is shut down, this will Often leave some heads at a significantly higher or lower elevation when compared with the source of water.

In addition to the problems referred to during startup of a system, additional problems have been recog nized with respect to areas of lower elevation, andduring the period immediately after the shut-down of an irrigation system. Thus, an amount of water will be present in the system at this point, and this water will tend to drain toward the sprinkler heads at a lower elevation whereby an undue amount ofwater will issue through these heads thereby over irrigating alocalized area. Similar problems result during operation of a system where there is a tendency for water distributed from the system to drain toward an area of lower elevation in which case even distribution of the water is not achieved. I

It is a general object of this invention to provide improved means for controlling the distribution of water and other liquids in irrigation systems and the like.

It is a more specific object of this invention to provide valve mechanisms particularly suitable for use in 2 large portable, stationary and mobile irrigation systems whereby the distribution of water or other liquids from the system can be controlled.

It is a further object of. this invention to provide a valve mechanism for use in irrigation systems and the like whereby the undue passage of water from spray heads can be prevented to thereby avoid localized Over-irrigation and other problems.

These and other objects of this invention will appear hereinafter, and for purposes of illustration, but not of limitation, specific embodiments of the invention are shown in the accompanying'drawings in which:

FIG. 1 is a perspective schematic illustration of an irrigation system suitable for incorporation of the concepts of this invention;

FIG. 2 is a vertical, cross-sectional view of a valve construction characterized by the features of the invention illustrated in the open position;

FIG. 2a is a cross-sectional view of a molded valve member suitable for use in-the practice of the invention;

FIG. 3 is a vertical cross-sectional view illustrating the valve construction in the closed position;

FIG. 4 is a cross-sectional view taken about the line 4-4 of FIG. 3; and,

FIG. 5 is a vertical, cross-sectional view illustrating a modified form of the invention.

This invention generallyrelates to an irrigation system or other systems wherein liquid is moved through lines and is adapted to pass out of spray heads connected to-the lines. The improvements of the invention are specifically related to means for controlling the flow of liquid to the spray heads including a valve .seat located in the passage which delivers the liquid to a spray head. A valve is mounted for engagement with the seal for cutting off the flow of liquid through the passage. The valve is resiliently mounted whereby it is normally urged against the valve seat but is unseated for liquid flow when the liquid pressure of the system is applied.

The valve is reciprocally mounted in a cavity positioned within the passage, and this cavity is vented to the atmosphere. When the valve is unseated, the pressure of the system serves to maintain the valve in the open position. Specifically, the spray heads restrict the outflow of liquid, creating a back pressure within the passage which holds the valve away from the valve seat in opposition to the resilient means.

When the liquid pressure is reduced, for example, when the system is shutoff, the spring action drives the valve back into engagement with the valve seat. Because of the venting, the atmospheric pressure on the liquid in the system is equalized, and the strength of the spring or other resilient means used can be selected to provide a particular requirement of pressure in the system to unseat the valves. Particularly where the valve is used as a control valve, the piston area is preferably larger than the valve seat area so that the valve will close with equal pressure on the piston and the valve, even in the absence of any spring.

In addition to providing the automatic operation described, the structure of the invention is adapted for use with means for controlling valve operation while the system is turned on. Specifically, a conduit may be connected to the vent whereby the cavity supporting the valve can be connected to a source of fluid pressure, preferably the line pressure for the system. With this arrangement, the combined line pressure and pressure of the resilient means associated with the valve will be greater than the line pressure normally unseating the valve, particularly as the piston area is larger than the valve seat area. Accordingly, by applying line pressure to the cavity receiving the valve, an individual spray head can be turned off while the remaining portions of the system are still operating. The venting to atmosphere or the application of the line pressure is preferably controlled by means of a separate operating valve provided for an individual spray head or group of spray heads.

FIG. 1 illustrates a structure comprising a section of an irrigation system suitable for incorporation of the concepts of this invention.

The illustrated structure includes an elongated horizontally disposed water distribution pipe secured on a supporting frame member 12. Water may be supplied from a feed pipe 14 which may extend downwardly to a well in the ground or which is-otherwise connected to a water supply. A swivel coupling 15 connects the feed pipe 14 with the distribution pipe 10. A plurality of spaced apart spray heads 16 are connected at intervals along the length of the distribution pipe.

A plurality of towers T are provided along the length of the frame 12, and these towers may be individually driven by motors mounted on the towers. An appropriate power supply, for example electrical lines extending along the frame, is provided for the individual motors. The motor operation may be controlled, for example, as described in Ririe, et. al. U.S. Pat. application Ser. No. 237,692. The cables 18 which extend from the central tower 20 to the moving towers may be utilized for controlling alignment of the towers, for example as described in Ririe, vet. al. U.S. Pat. application Ser. No. 237,693. It will be appreciated that the structure described is referred to only for purposes of illustration, and that the concepts of the invention are useful in connection with other irrigation systems, such as the portable and stationary systems referred to, and in connection with systems having comparable operating characteristics. An example of a comparable system is an effluent distributing system wherein liquid waste materials are disposed of by distribution over large areas by means of spraying systems. Systems which are employed for distribution of fertilizer are also applicable to the concepts of the invention.

FIGS. 2 through 4 illustrate a valve arrangement adapted to be incorporated in a line 22 extending to a spray head 16. The construction includes an inlet end fitting 24 which is internally'threaded for connection with the pipe section 26 of the line 22. The end wall 28 v of this fitting defines a passage30 and a valve seat 32 formed on its outersurface at the end of the passage. This fitting is cemented within a suitably dimensioned bore defined by the main body 34 with the annular rib 36 providing for accurate positioning of the fitting. Alternatively, these parts can be molded in one piece.

A valve cylinder 38 defining internal cavity 40 is positioned within the main body 34. As best illustrated in FIG. 4, this valve cylinder is formed integrally with the outer wall of the main body by means of webs 42. This provides an annular flow-through passage 44 for the construction. The cavity 40 is tapered since the structure is preferably formed of injection molded plastic, and the taper facilitates core removal.

The passage 44 extends to an outlet end fitting 46. This fitting is also internally threaded for connection with pipe section 48 of the line 22. As indicated by the arrows in FIG. 2, the movement of liquid through the construction involves flow through the opening 30, and through annular passage 44 around the valve cylinder.

A valve 50 is received within the cylinder 38 for reciprocal movement therein. Spring 52 has one end bearing against the end wall 54 ofthc cylinder, with the other end bearing against the front wall 56 of the valve. The bore within the valve may be tapered as illustrated to facilitate manufacturing. Molded-in lips 57 (FIG. 2a) may be associated with the valve 50 for purposes of sealing the valve relative to the cavity 40 since it is important to preventthe entry of any substantial amount of liquid into the area of the cavity behind the valve.

The main body 34 defines a passage 58 which serves to vent the cavity defined by cylinder 38. In one form of the invention, the vent may be open to the atmosphere either directly or through a line 60 attached to the main body at this location.

ln the operation of the valve construction described, the valve 50 is adapted to engage valve seat 32 when the system is shut down. When pressure is applied, for example by pumping liquid in the line, the liquid pressure is adapted to unseat the valve in opposition to the action of spring 52. The back pressure resulting from the restriction provided by the sprinkler heads wil maintain the valve open during operation.

When the system such as an irrigation system is shut down, water will still be located in the system, and for sprinkler heads located at a lower elevation, a head of water will exist which will tend to force water toward the sprinkler heads. At this point, however, the valve construction will operate to prevent passage of the water to the sprinkler heads since the valve 50 is designed to engage the seat 32. The water in the line will itself be under atmospheric pressure so that the provision of vent 58 will offset this pressure and thereby combine with the spring 52 for closing the valve. In selecting a spring 52, the proper spring force is primarily determined by the best operating pressure for the sprinkler used. Some sprinklers operate better under higherpressure than others, the higher pressure providing adequate break-up and hence minimum erosion of soil.

FIG. 3 illustrates the valve construction in the closed position. In addition, the figure illustrates the connection of the line 60 to a separate valve 62 having at least two operating positions. Thus, the valve 62 is exposed to atmosphere in one position whereby the above described automatico'peration of the system will occur. in a second position of the ,valve, the line 60 is connected through line 64 we source of pressure whereby the cavity 40 receiving the valve 50 can be subjected to a pressure other than atmospheric. In a typical utilization of this arrangement, the line 64 is connected to the water feed line whereby the pressure applied through line 60 will equal the pressure applied on the opposite side of the valve; Under these circumstances, the spring 52 will upset the balance of pressure which will result in seating of the valve 50. The larger surface area of the piston when compared with the surface area of the valve as also serves 5 a control factor and simplifies closing. i

The arrangement of FIG. 3 can be utilized for selectively controlling a sprinkler head or bank of sprinkler heads while the system is operating. For example, if a particular area of a field tends to be over-irrigated, the system of FIG. 3 can beselectively introduced to rcduce the amount of irrigation in a particular area while water is being applied in other areas. The operation of a valve 62 could be controlled from the central tower by any suitable means.-

FIG. 5 illustrates a further alternative form of the invention. In this instance, a piston 66 receives a spring 68 within a cavity 70 defined by the piston. The piston is reciprocally received-within thecavity 40 defined by the cylinder 38, and the spring serves to force the valve. end 74 of the piston toward the valve seat 32.

The opposite end of the spring seats on the head 76 of an adjusting screw 78. This adjusting screw is threadably received within a bore defined by the end wall 54 of the main body 38. The end of the screw defines a slot 80 for rotation of the screw.

The combination of the piston 66 and associated adjusting screw permits adjustment in the valve operation to suit different sprinkler requirements.- Specifically, with the arrangement of FIG. 5, the valve constructions for a system can be quickly'accommodated upon installation of a system so that the operating pressure of the system can be regulated depending on requirements.

The valve end 74 may comprise a rubber button seal to reduce the possibility of leaking when the valve is seated. A U-shaped cup seal 75 serves to seal the cavity 40 during movement'of the valve in either direction. This seal is particularly useful where the cavity is tapered since it is effective without maintaining close tolerances. g

The concepts of the invention have been found to be highly suitable for preventing undesirable operation of irrigation systems and the like, particularly with reference to the premature passage of liquid through spray heads during start-up and draining after a system has been shut down. The valve constructions utilized for this purpose can be efficiently manufactured, and in view of the relative simplicity thereof, the constructions provide highly reliable operation. It is preferred that the various components be manufactured from materials which will resist corrosion. For example ABS (cycolac), may be used for all parts except the piston which is efficiently made from low density polyethylene. The constructions are then readily usable in systems handling fertilizer, waste effluents, and other corrosive materials.

The systems of the invention are particularly useful in permanent underground irrigation systems and portable aluminum solid set systems, especially during the start-up period. Many of these systems are extensive enough so that after the pump is turned on, 5 or 10 minutes will elapse before the system comes up to pressure. During-this transient period the sprinklers near the water source will be under sufficient pressure to cause some flow of water, but not enough pressure to operate the sprinkler properly. The effect of this is to cause soil erosion because of-a stream of water with no break-up. With the valves of the invention in place on such a system, the water will;not flow until a predetermined pressure has been reached. When this pressure is attained, the whole system comes up to pressure almost simultaneously.

It will be understood that various changes and modifications may be made in the above described system which provide the characteristics of the invention without departing from the spirit thereof particularly as det'ined in the following claims.

That which is claimed is:

1. In an irrigation system and the like wherein liquid is moved through linesfrom oneposition to another and then passes through spray heads or other restrictive orifices connected to said lines, the improvement in means for controlling the flow of liquid to the spray heads comprising a valve seatlocated in a passage employed for delivering liquid to a spray head, a valve for engagement with said seat and for cutting off the flow of liquid through the passage, means positioned in the passage defining a cavity which reciprocally receives the valve, resilient means in said cavity urging the valve toward said seat, the liquid pressure in said line during operation of the system serving to unseat the valve and to hold the valve unseated, and including a separate passage entering said cavity and communicating the cavity with atmospheric pressure so that the pressure difference across said valve is the said liquid pressure whereby relief of said liquid pressure in said line places the valve in engagement with the valve seat in response to the force of said resilient means.

2. A construction in accordance with claim 1 wherein said cavity supports said valve for movement of the valve coaxially relative to said passage, and meansfor sealing said cavity against theentry of liquid into the cavity. 1

3. A construction in accordance with claim 2 wherein the inner wall of said cavity and the outer wall of said valve are cylindrical, said means for sealing the cavity against entry of liquid comprising a seal defined by the outer wall of said valve.

4. A construction in accordance with claim 2 wherein said cavity is defined by a member supported in spaced relationship relative to the inner wall of said passage, the outer wall of said member and the inner wall of said passage being cylindrical and defining an annular liquid passage therebetween.

5. A construction in accordance with claim 4 wherein said member is formed integrally with the inner wall of said passage,'the support for said member comprising at least one web extending between said inner wall and said outer wall of said member.

6. A construction in accordance with claim 4 wherein said resilient-means comprises a spring having one end seated within said member, the other end of said spring engaging said'valve.

7. A construction in accordance with claim I including a conduit connected to said separate passage, a variable position valve provided for said conduit, said variable position valve being open to the atmosphere in one position for thereby applying atmospheric pressure through said conduit to said cavity, a fluid source connected to said conduit, said variable position valve in a second position communicating said fluid source with said cavity for applying fluid pressure within said cavity when said variable position valve is in said second position whereby the force applied by said fluid pressure and said resilient means opposes said liquid pressure.

8. A construction in accordance with claim 7 wherein said conduit is connected to a line carrying said liquid whereby placing of said variable position valve in said second position results in the application of liquid pressure of equal force on both sides of said valve whereby the pressure applied by said resilient means operates to move said valve into engagement with said valve seat.

9. A construction in accordance with claim 1 wherein said resilient means has one end engaging said valve, a set positioned within saidcavity for engagement with the other end of said resilient means, and means for adjusting the position of said seat within the cavity to IZIIQS.

Claims

1. In an irrigation system and the like wherein liquid is moved through lines from one position to another and then passes through spray heads or other restrictive orifices connected to said lines, the improvement in means for controlling the flow of liquid to the spray heads comprising a valve seat located in a passage employed for delivering liquid to a spray head, a valve for engagement with said seat and for cutting off the flow of liquid through the passage, means positioned in the passage defining a cavity which reciprocally receives the valve, resilient means in said cavity urging the valve towArd said seat, the liquid pressure in said line during operation of the system serving to unseat the valve and to hold the valve unseated, and including a separate passage entering said cavity and communicating the cavity with atmospheric pressure so that the pressure difference across said valve is the said liquid pressure whereby relief of said liquid pressure in said line places the valve in engagement with the valve seat in response to the force of said resilient means.

2. A construction in accordance with claim 1 wherein said cavity supports said valve for movement of the valve coaxially relative to said passage, and means for sealing said cavity against the entry of liquid into the cavity.

5. A construction in accordance with claim 4 wherein said member is formed integrally with the inner wall of said passage, the support for said member comprising at least one web extending between said inner wall and said outer wall of said member.

6. A construction in accordance with claim 4 wherein said resilient means comprises a spring having one end seated within said member, the other end of said spring engaging said valve.

7. A construction in accordance with claim 1 including a conduit connected to said separate passage, a variable position valve provided for said conduit, said variable position valve being open to the atmosphere in one position for thereby applying atmospheric pressure through said conduit to said cavity, a fluid source connected to said conduit, said variable position valve in a second position communicating said fluid source with said cavity for applying fluid pressure within said cavity when said variable position valve is in said second position whereby the force applied by said fluid pressure and said resilient means opposes said liquid pressure.

9. A construction in accordance with claim 1 wherein said resilient means has one end engaging said valve, a set positioned within said cavity for engagement with the other end of said resilient means, and means for adjusting the position of said seat within the cavity to thereby vary the pressure applied by said resilient means to said valve.

10. A construction in accordance with claim 9 wherein said means for adjusting comprises a screw having one end received within said cavity, said one end of said screw providing said seat for said spring whereby the position of the seat varies as the screw rotates.