US1527315A

US1527315A - Flow-control system

Info

Publication number: US1527315A
Authority: US
Inventors: Chester W Larner
Original assignee: William Cramp & Sons Ship & En
Current assignee: William Cramp & Sons Ship & En; William Cramp & Sons Ship & Engine Building Co
Priority date: 1920-03-17
Filing date: 1920-03-17
Publication date: 1925-02-24
Anticipated expiration: 1942-02-24

Description

C. W. LARN ER FLow CONTROL SYSTEM Filed March 17, 1920 Feb. 24. l 925.

Patented Feb. 24, 1925.

TIE

CHESTER W. LARNER, 0F PHILADELPHIA, PENNSYLVANIA, SSGNOR T0 THE JW111- LIAM CRAM @a SONS SHIP & ENGNE BUILDING COMPANY, A CORPORATION OF PENNSYLVANIA.

FLOW-CONTROL SYSTEM.

lApplication'filed March 17, 1920. Serial Noi.v 366,676.

To all whom t'mag/ concern: i

Be it known that I, CHESTER W. LARNER, a citizen of the United States, residing at Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented certain new and useful Improvements in Flow-Control Systems, of whichthe` following is a specification.

This invention relates to ilow control systems andv particularly to a valve control means for the ilow through water mains. The chief object of the invention is to provide simple and eiiicient means for governing the movementof a main control valve so that its degree and rate of opening or -closing are at all times under complete control.

To avoid water hammer or sudden rushes of flowin the operation of water main valves it is often necessary to move the Valve slowly when near its seat though the remainder of thel valve stroke may be at any desired rate. For instance in opening the valve of a hydraulic power system, a too quick opening of the valve may admit the full flow suddenly into empty spaces with great rush of ilow and abrupt stopping as the spaces are filled and resultant dangerous rise in pressure. In such case the proper operation is to open the control valve slightly and hold it partially open until the empty spaces are filled or primed after which the opening movement of the control valve may be resumed at any desired rate.

Similarly in closing the valve it is usually the last portion of the closing movement that most suddenly` decelerates the llow and causes water hammer and by easingoff or damping this closing movement in its Final phases the deceleration of the stream will be suliiciently gradual to avoid' dangerous rise in pressure.

In the apparatus of this invention the main control valve a't any point in its opening or closing may be readily slowed down or stopped and then again accelerated so that the operator is enabled to exercise the desired control and eilect the proper damped or interrupted movement of the valve. The movement of the valve is synchronous with the movement of the operating mechanism.

1n the accompanying drawings illustrating one embodiment of the invention,

Fig. 1 is a diagrammatic plan viewof a water main control system and Fig. 2 is vertical sectional view on line 2 2 of Fig. 1.

In the specific embodiment of the invention illustrated in the accompanying drawings a water power main 1, 2 is provided with an enlarged portion 3 within which moves a valve plunger 4 seating at 5 across the neck of the enlarged portion 3 to close the main `and moving back in cylinder 6 to open the main. The valve plunger 4 is hollow and y p in cylinder 6 and the body of the valve 4 is of reduced diameter providing a space S between the piston 7 and the end- 9 of the cylinder 6. A by-pass 10 is provided for admitting liuid pressure from the water way 12 into the space 8 when the valve 'plunger is in its closed position and an opening 13 is provided in the cylinder 6 for admitting fluid pressure from the water way 12 to the space 15 on the other side of the valve plunger 4 and Within the cylinder 6.

The annular space 8 is connected to eX- haust through a valve 24 and the space 15 is similarly connected to exhaust through a valve 23 while another outlet from this space 15 is provided by the opening 20 in the nose of the valve plunger 4 controlled by valve 21. Valve 23 isk considerably larger in flow capacity than port 13 in order that pressure may be exhausted from chamber 15 by valve 23 notwithstanding the simultaneous admission of pressure through port 13. To open valve plunger4 valve 23 is opened to exhaust pressure from chamber. 15 whereupon pressure through/by-pass 1() into annular space 8 against piston 7 will begin the opening movement of the valve plunger 4, valve 24 being closed. The partial opening of plunger 4 will close by-pass 10 by the end 9 of the cylinder 6 and thereprovided with piston 7 moving after pressure for the annular chamber 8 the plunger 4 in its open positionv by eooperation with valve 21 in a manner here1n after more specifically described. To close plunger 4

valves

21 and 23 are closed and valve 24vopened so that pressure will be exhausted from the annular chamber 8 and admitted through the port 13 behind the plunger to close it.

Controlling of the port 13 and by-pass 10 being automatic by the movements of the plunger 4 the governing of valve plunger 4 is effected by the operation of

valves

21,

and 24 and to place this control conveniently7 in the hand of the operator so that by movement of a. single control member he may properly coordinate the movements of these valves. mechanism is provided which in the specific embodiment shown in the drawings comprises an operating rod 30 moved upward to cause a closing movement of plunger 4 and downward to cause an opening movement of the same. To the rod 30 is pivoted a floating lever 31 connected at the end 32 to mechanism controlling the valve 21 and at the end 33 to mechanism alternatively controlling the

valves

23 and 24. The end 32 of the lever 31 is connected by link 34 to arm 35 of shaft 36 passing into the space 15 within the cylinder 6 and carrying at its inner end the arm 37 linked by rod 38 to the valve member 21 sliding in bearing 39 in plunger 4. It is obvious that upward movement of the rod 30 will draw upward on link 34 to tip arm 37 to the right (Fig 2) to shut valve 21. Upward movement of operating rod 30 will also draw upward on link 41 and turn counter-clockwise arm 42 and lever or walking beam 43 both of which are connected to a rotatable stud 44 in a bearing 45 supported by the valve casing. The downward movement of the left end of lever 43 closes valve 23 while the upward movement of the right end of lever 43 opens valve 24 so that the shutting of valve 21 is accompanied by the opening of valve 24 and the closing of valve 23 and it is obvious that the main valve plunger 4 will be caused to move in a direction to close.

Valves

23 and 24 are preferably of the plunger type shown having their

plungers

53 and 54 controlled by

rods

63 and 64 respectively extending upward through the forked ends of lever 43 and downwardly spring pressed by springs `48 and 58 so that both of the valve rods '63 and 64 are normally pressed downward andboth the

valves

23 and 24 normally closed.

With the linkages as above described and following a. slight upward movement of operating rod 30 it is apparent that the resultant closing of the plunger 4 will permit the arm 37 to tip counter-clockwise (Fig. 2) letting the floating lever 31 turn clockwise and with it the lever 43 also clockwise so as to lower control rod 64 of valve 24 to restrict said valve, the previous counter-clockwise movement of lever 43 having compressed spring 58 and raised'said rod. Unless the operating rod 30 is further moved upward then the closing movement of valve plunger 4 will automatically close valve 24 to restrict the outflow from the space 8 and stop the closing movement of the plunger. The operator therefore by proper manipulation of the rod 30 may move the plunger 4 to any extent desired. The rate of movement of the valve 4 is also dependent on the rate of operation of rod 30 and it may he preferable in installations where there is danger of excessive rise in pressure upon ytoo sudden movement of the valve 4, to limit the rate of movement of the operating rod 30 in the hands of the operator so that a certain rate `of movement of the valve 4 cannot be exceeded.

When the closing movement of the valve plunger 4 is completed by the seating of.

the. valve if the final increment of the valve movement which permits rod 38 to move to the right (Fig. 2) to tip the lever 43 clockwise does not permit control rod G4 to entirely close plunger 54 of valve 24 under the action of spring 58 then lthe movement of rod 30 should be reversed slightly by the operator until valve 24 is permitted to close so that all the

valves

21, 23 and 24 will in the closed position of the plunger 4 be normally closed while the port 13 and by-pass 10 will be open.

To open the valve plunger 4 the operator moves operating rod 30 downward tending to draw valve 21 open and at the same time tending to turn lever 43 clockwise to draw up control rod G3 against the compression of spring 48 and thus open the plunger 53 of valve 23 so that pressure is exhausted from the chamber 15 while it is admitted to Chamber 8 through liv-pass 10. lVhen operating rod 30 is drawn downward rthe first eHect is to transmit a pressure to rods 34 and 41 thus pressing the left end of lever 43 up against the enlargement 49 of rod 63 and tending "to compress spring 48. At the same time the pressure on rod 34 is transmitted through the various connections to valve 21 and if the adjustment of spring 48 gives sutficient resistance, valve 21 will he pulled off its seat before rod (i3 is lifted. ln this `case valve 21 will open until it is stopped by bearing 39 and then valve 23 will be opened, but otherwise valve 23 will open first starting the plunger open and valve 21 would open only when the pressure on the outside of the plunger nosehas accumulated suiieiently.

This operation, of course, at the same time leaves valve 24 closed by the pressure of spring 58 and if the operator continues the downward movement of rod 30 the openliti ing movement of the main plunger 4 will continue in a way similar to that already described for the lclosing movement of the plunger. In eitherv case if the plunger is either completely opened or fully closed the motion of rod 30 should be slightly reversed to restore walking beam or lever 43 to its horizontal position and permit valve 23 or valve 24 to close. f

In valves of the type described it is of course important that plunger4 should be held positively in both the open and closed positions so that it cannot accidentally drift closed when it is open or drift open when it is closed.A Furthermore this result should not be accomplished by a continuous exhaust of pressure through

valves

23 and 24 because of the water waste which would result and also because of the destruction effects of continuous flow through the valves.

Valves

23 and 24 should always be closed except when plunger 4 is in operation. With

valves

23 and 24 closed if plunger 4 is closed it will beheld in that position by the unbalanced pressure of the conduit applied on the entire area of the plunger seat and it is impossible for plunger 4 to open accidentally.. When plunger 4 is open, however, it can be held in that position only by its own inertia and such difference of pressure inside. and outside of plunger 4 as may be effected without opening valve 23. When plunger 4 is open and there is no flow in the conduit the pressure in chambers 15 and 8w and waterway 12 is equalized by leakage communication between them and plunger 4 is held open only due to its weight. This, however, is sufficient since there is no tendency for it to close in still water. If, however, water is flowing through Ithe valve the pressure communicated to chamber 15 throughrrestricted port 13 will be higher than the' pressure exerted by the Howing water on the outside of plunger 4 because the velocity of flow at the former point is lower than at the latter and unless some means be provided for equalizing these pressures the plunger 4 mayV start to close and automatically open valve 23 by means of the connectionsbetween plunger 4fa'nd valve 23. This tendency is corrected in the valve described by the use of valve 21 which is so connected to rod V30 thatY when plunger .4 is open valve 21 -is also, open. thus equalizing the pressures inside` and outside of the plunger 4 or, if suitablyk designed, reducing the pressure in chamberV 15 below that on the outside of the plunger nose by utilizing the suction effect of the flowing water on the nozzle in the nose of the plunger. This effect is more readily accomplished by restricting the pressure supply through port 13 but port 13 cannot be entirely cut o by plunger 4 in its open.

position because there would then be no means of supplying fluid to chamber l5 to begin the closing movement of plunger 4.

This system of control combines two alternative sets of movements. When valve 23 is open valve 24 is necessarily closed and when valve 24 is open valve 23 is necessarily vclosed and similarly whenpressure is applied to open valve 21 it is also necessal-ily applied to open valve 23 and close valve 24 and when the pressure is exerted to close valve 2l it is also exerted to open valve 24 and close valve 23. This distribution of thekvalve movements is automatically attended to by the mechanism shown without any-attention on the part? of the l operator who simply moves the control rod 30. The movement of the valve may be interrupted at any point and the rate of movement is necessarily dependent upon the rate of movement of operating rod 30 so that in the hands of a skillful operator the plunger 4 may be rapidly moved when away from its seat witha damping orinterruption of the movement when near its seat. This system may therefore be utilized to secure both the priming and damping characteristics often necessary to avoid undue rise in pressurein the system and at vthe same time the remainder of the'valve movement may approximate closely the highest desired rate.

I cl-aim:-

l. In a system for controlling the flow of a fluid the combination with a main valve, of a control member therefor, a floating differential element actuated by said control member and mechanism operated alternatively by said element to open or close said main valve comprising alternatively operated fluid pressure valves.

2. In a flow control system the combination with a nrain: valve, of fluid pressure control means therefor comprising plurality of alternatively operated valves and another valve operable -alternatively with one of said plurality of valves, and means for automatically controlling the interaction of said valvesi 3. Ina flow control system the combination with a main valve, of fluid pressure control means therefor comprising a plurality of alternativelyy operated valves, a cooperating valve and a floating differential ele-l ment selectively actuating certain of said valvesand dependently controlling the operation of said coopera-ting valve.

4. In a flowcontrol system l"the combina- 'tion with a mainvalve, of means for closing or opening said valve comprising an operating member, a floating differential element actuated thereby, and fluid pressure control means comprising valves cooperating in -altern'ative sets and ycontrolled by said member. l

5. In a system for controlling'the flow of a fluid the combination with a main valve having a piston portion with fluid pressure chambers on opposite sides thereof, of valves controlling the exhaust of pressure from said respective chambers, and fluid pressure means for operating said valves comprising a connection to said main valve adapted to limit the movement of the main valve by a predetermined movement of said operating means. y i

6. In a iioiv control system the combination with a main conduit valve having op,

positely acting fluid pressure chambers and permanent connections permitting conduit pressure to separately1 pass to said chambers, of exhaust valves of' greater discharge capacity than said pressure connections and adapted to alternatively exhaust the pressure from said chambers, and means for operating said v-alves comprising a control member relatively movable with respect to said exhaust valves during movement of the main valve to limit the movement of the main valve according to the movement of the control member.

7. In a flow control system the combination with a main conduit valve having a tapering end and a passage therethrough connecting the interior of said main valve with the fluid in said conduit, a valve con-4 trolling said passage, a second valve con- 9. In a flow control systemgthe combina-y tion with a main conduit valve having a piston portion between fluid pressure chambers and means permitting pressure to pass from said conduit to said chambers, of valves for alternatively exhausting the pressure from said chambers, and fluid pressure meansA for operating said valves comprising a floating differential lever connected to the main valve to limit the movement of the main valve according to the movement of the control means.

10. In a flow control system the combination with a main conduit valve having oppositely acting fluid pressure chambers and a tapered end with an opening from one ot' said chambers to a region of low pressure in the fluid way, of permanently open high pressure connections to said chambers from said fluid way, a valve for said low pressure opening from one of said chambers, an exhaust valve for the other of said chambers, and control means alternativelyfoperating said valves and automatically actuated by movement of. J[he mainl valve to limit the movement of the main valve according to a predetermined movement of the 'control means. I

ll. In a llow control system the combina-- tion with a main conduit valve having op-` positely acting fluid pressure chambers Aand means permitting pressure to pass from said conduit to said chambers, of valves for alternatively exhausting -the pressure from said chambers, and fluid pressure means for operating said valves comprising a floating differential member connected to the main valve to automatically. hydraulically balance said main valve and limit the movement of the main valve according to the movement of the controlmeans.

l2. In a flow control system the combination with a main conduit valve having oppositely acting fluid pressure chambers permanently open to pressure from the Vfluid way, of exhaust valves for said chambers and operating means for said exhaust valves f comprising a single member alternatively lopening said exhaust valves and connected to said main plunger so as to be movable therewith to automatically hydraulically limit the movement of said plunger according to a predetermined movement of said control means.

13. In a flow control system the combination with a main valve for controlling` the ow through a conduit, of fluid pressure operating means therefor, a plurality of valves controlling the movement of said main valve, a lever for alternatively opening one or the other of a pair of said valves, a second lever for alternatively actuating another valve and said first named-lever and an operating member for actuating said second named lever.

CHESTER W. LARNltR.