US 2658522 A
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Npv. 10, 1953 Filed May 19, 1947 C. J. COBERLY FLOW METERING DEVICE 3 Sheets-Sheet 1 Z/VVENTOR: CLARENCE J COBEPLV By H15 A TTORNE v5 Nov. 10, 1953 c, J, co Y 2,658,522
FLOW METERING DEVICE I Filed May 19, 1947 3 Sheets-Sheet 2 [/v VEA/TOR CLARENCE d COBERLY By #15 A T7ORNEY5 HARP/5, lf/scm Fosrmffixam/s Patented Nov. 10, 1953 FLOW METERING DEVICE Clarence J. Coberly, Los Angeles, Calif., assignor, by mesne assignments, to Dresser Equipment Company, Cleveland, Ohio, a corporation of Ohio Application May 19, 1947, Serial No. 748,921
This invention relates to flow metering or governing devices, and more particularly to a device for controlling the flow of a high pressure operating fluid to a fluid operated pump.
The invention is of particular utility in the oil industry and, consequently, is described in connection with such use, although it is to be understood that I do not intend to be limited thereby since the invention is susceptible of other diverse uses.
Fluid operated pumps for use in deep Wells ordinarily include a fluid motor, with a pump unit operatively connected thereto, adapted to pump oil or other well fluid from the well up through a production conduit leading to the top of the well. The fluid motor and the pump unit are customarily at, or near, the well bottom and, consequently, far removed from observation, with the operating fluid pumped to them under pressure from a surface pumping unit through a supply conduit, and it becomes important to have automatic controlling devices with which to regulate the flow of the operating fluid to the fluid motor in accordance with conditions existent at the well bottom. In order to facilitate control and observation of operation, it is desirable to have the control devices for a large number of wells closely grouped and such a group of controls may conveniently receive operating fluid from a single high pressure surface-pumping unit through a manifold common to all members of the group. It is furthermore desirable that the operating fluid, passing through the individual controls,
should how to the individual wells at pressures" and rates of flow which are peculiar to the operating conditions of each well and which are governable individually in response to those conditions. The fluctuations of pressure and flow occurring at each of the fluid operated pumps fluid passing to each pump must be regulated to suit specific circumstances. The specific operating conditions may include, as tumor variables, the rate of production which may be required of a given well from time to time, and fluctuations in the load on the fluid operated pump as represented by the pressure of operating fluid required -to operate the fluid motor at a predetermined speed and as caused by such factors as changes in the density of the liquid entering the pump, emulsiflcation of the liquid to various de grees, and gas entering the pump along with the liquid. As a constant, the maximum pressure to which it is desirable to. load the supply conduit or the fluid motor should be considered. Variable factors which may be termed minor but which are none the less important in maintaining a calculated rate of production include the specific gravity and the temperature of the operating fluid.
It is, therefore, a primary object of my invention to provide a control device for a fluid operated pump which may be installed in the supply line of an individual pump leading from a manifold supplying operating fluid to a group of pumps and which will convert the hydraulic conditions of the manifold to hydraulic conditions suitable to the individual pump.
Another object of my invention is to provide a control device for governing the flow of operating fluid from a source of supply to a fluid operated pump which will regulate the speed of the pump by regulating the volume of flow of the will regulate the intake of fluid from the source of supply thereof so as to prevent the pump from exceeding a desired maximum speed whenever the pressure at which the fluid is released from the control device is less than a selected maximum and which will, whenever the pressure at which the fluid is released from the control device has attained the selected maximum, thereafter regulate the intake of fluid so as to prevent the pressure from exceeding the selected maximum.
A further object of my invention is to provide a control device which will prevent racing of a pump by decreasing the rate of flow of operating fluid thereto in response to a decrease in pressure in the fluid passing from the control device to th pump below a selected value.
A still further object of my invention is to provide a control device for governing the flow of operating fluid to a fluid operated pump which will so compensate for changes in the temperature of the fluid at the control device that any rate of flow through the control device will be' volumetrically constant when measured at a constant temperature.
Yet another object of my invention is to provide a control device for the purpose indicated which may be adjusted for use with operating fluids of varied specific gravities, so as to maintain with such varied fluids like volumes of flow under like conditions of entrance and discharge pressures.
Another object of my invention is to provide a control device for the purpose indicated hav ing auxiliarybiitlt for the supply" of'operating fluid at a regulated pressure to accessory devices in addition to the pump to which it is primarily connected, and so arranged that its operation may be regulated by back pressure impbsedon it by an accessory device.
Other objects and advantages will appear in the following specification and'in the drawings,"
lieis a n ar ed. vert ca e t enal. v ew. taken on the line 44 of Fig. 1, and showing;
h arr n m nt and the. ni reommun eat n i5 he ma i e vel t ilot. al e a d.
xi 'e i g orifi he. a ves ndtlie rifice ing. ehpwn. in c ed esi ie s Fig! is a h r n a .eeetiena vievv taken n he e. ff i and. h w ng be flow.
ii 6 Li n enlar ed v r ie l eet nal view taken on the line B 6 of Fig. 1, and showing the pressure controllmechanism and auxiliary outlets;
i 7 is a vertical sectional view one further enlarged scale, oi a detail of the pressurecon 9 val e ewem 7 a 6 1 d.
Fie 8 is a r mmatic. lustrationet the.
principal flow channels of my invention, each channeliormed by a -group of passages being e l ie he" enee u b rfq ne 1. 1 1.- ber of the group.
Referring to the details of the drawings, I
show a manifold section 2|] to which a housing 21 is secured 'by bolts 22, and it is to beunderifiififisiifej lu ali meni d ect o s L.v may e. tab y eeur dte aeh. theriaende i lf e ee s as. e er eni u us. men.- ia-"ee h. ee eeet .whie y ear t wn. .he e- Th meniiekiseetienlfl. e mvideq. ith. a shutofi valve 23, which is mounted on a, valve aflgb e edi d eem dbya oc i can.
endlwh'iehseie. l nen. ev lve seat 6. hread: edly emed. in. a t. 21 gne with. n
'i the' eue n 1-. To eal the nt.
between the manifold section ZILandjthe housi 1 he f rme P ide with. an nnula ridge w i e ith nen nnula e. .0.,
in the. housingjlfand is there held against a gasket- 3!. A discharge pipe 33. is secured to a flange'member 34 which is secured to the housing 2| in alignment with a discharge port 35 f's'tuds '36, eji rit. etwee e. flan eend. the housing being sealed similarlyto that be; wee h manifold. 'pii ne dth ous ng b an annular ridge 31, held against a gasket 38 in Y A flow circuit is thus afifannular groove 39. formed from a source of supply (not shown) of high pressure operating fluidthrough one or more; of the manifoldsections 211, thevalvei23, inlet' port '28, .andthe -housing- 2 I with .its hereinafter described, mechanism to the discharge porty'3'5 and discharge'pipe 33,which.leads to a" fluid operated pump (notfsho'wn) situatedina welltand-governedin its individual operation by: the mechanism secured to the specific manifold.
ei e. li pl h WhiQh. h e atin flu d section 20. A grease inlet 40 of the gilemite type," may, be priovided throiigh Wh t heavy grease ma be'fdrced into a groove 4| surrounding the valve stem 24 to prevent leakage of high pressure operating fluid when the locking cap 2,5 is removed.
"The housing 2| is provided with a cylindrical chamber 435m axial alignment with the inlet port"28.fandconnected thereto by smaller axial bores '44 and 45." valve casing 46, comprising an upper casing'm'ember 41 and a lower casing member 4}, threadedly joined, is threadedly secured in the chamber 43, the upper casing member '41 having a head 49 threaded externally for joining to the housing. 2| and provided with spanner sockets 50. by which, by. use of a suitable tool, the valve casing 46 maybe. inserted. and removed. as, a unit, togetherwith its. contents. A flange 5]. on the upper, casing. member 41 limits the depth to which. the valvecasing 46, may be. inserted in the chamber 4,3.so. as.
to leave a space.52 below the lower. casingmember, 43 Thelower casing member 48. base. tue bular, extension 53., fitting closely within the bore 44 and extending partly therethrough, and, a furtherextension 5.4; of reduced diameter, fitand a pilotvalve 51, to be describedmore fully hereinafter, are housedwithinthe valve. CB-Sr. mg 4, with the main, valve, in communication,
with the inlet port 28 by means of. a. passage. .55,
ai ine. ew nd of. the extension 54.. and in. communication With, the annular. space ;.by.
means of radial ports '59 ,in the. extensionv 5.4,. A d a 1 0 is provided for the main. valve,.
5 6,. at.the, end oi the passage 58,adjacen.t the. radial ports 59 Sealing rings 6]. on. the. ex. 1$ Qn., a dfiic n the ext nsionjfi ,seal the. lower casing member 48 relative to. the hou5-.,
nel bov and, belowthe radial ports 59 Acbamberfl. o med i he. ousin .2 I in i nment i hhe isc a e .portss and has. r ads H e eiveands nreavaiye body; of QI tr a he. va v 0.dy.6.4...ha at.
wer. or i n, 5 h h. f, reduced diameter,
the, valve .64. The valvechamber 69 being open tits. l e nd ommu ica e it t e. di char ortia. shenhawn in .F ,.main.n
passages jm extend into the housing 2| at, op posite sides of. the chamber 62 being closed attheir outer ends by plugs 1| and intersecting at;
.9 d. heennula n e su r un in the controlyalve 65, and at the other end the am ulanspac 5 adiaeen em n v hl pmYiQin L OWeh nne s om t e tp r 2H ischa port. 35 when the main valve and,
the control valve. are open The control valve 65;,is of plungertype having.
aplunger. head .13 whichfits slidably within the,
reduced portion; ofthe valve body 64 so asto cut. ofi-.,the valve. chamber. vI59 fromwthe annular. space 61, and the radialports. 68 form a metering, orifice means.14..th e effectivev area of which. may
valve body.64.above the. valvechamberfifi; The
valve stem 15 is reduced in diameter above the threads 16 so as to leave an annular space 11 between the valve stem and the valve body 64 and this annular space is in communication with the lower face of the plunger head 13 by means of a longitudinal passage 18 in the plunger head and valve stem and a radial passage 19 in the latter. Above the annular space 11, the valve stem 15 is packed by packing 80 and a gland 8| and the upper end of the valve stem, extending above the valve body 64 is provided with a micrometer thimble 82 registerable with a skirt 83 on the valve body 64 graduated to show the rate of flow which may be expected through the metering orifice 14 throughout its range of setting, or in other convenient units such as the barrels per day pumped by the fluid operated pump at such rate of flow. The skirt 83 is held to the valve body 64 by a set-screw 84, and the thimble 82 is adjustably secured to the valve stem 15 by a setscrew 85. Spanner sockets 86 are provided in the valve body 64 by which the valve body and contents may be installed and removed as a unit by use of a suitable tool.
The interior of the valve casing 46 is divided by a transverse partition 80 held in position by an upper lining sleeve 89 and a lower lining sleeve 90 which bear against the upper and lower casing members 41 and 48, so as to form upper and lower cylinders 9| and 92. The partition 09 has an upper central boss 93 extending upwardly into the upper cylinder 9|, and a lower central boss 94 extending downwardly, the exterior of the latter providing a sliding fit guide for a tubular valve stem 95 of the main valve 56 and for a main valve piston 96 integral with the valve stem 95 and reciprocable within the lower cylinder 92. The lower end of the valve stem 95 is fitted with a valve head 91 adapted to seat upon the valve seat 60, and is reduced in diameter to provide an annular space 98 within the extension 54 of the lower casing member 48 of sufficient length that movement of the valve stem 95 to any position within its scope will leave the radial ports 59 fully uncovered. The central bosses 93 and 94 are provided with an axial bore 99 forming a bushing for a needle I of the pilot valve 51, and the lower end of the bore 99 is counterbored and threaded to receive valve seat IOI and a plug I02 for retaining it. The valve seat |0| and plug I02 have an axial passage I03 in extension of the axial bore 99 communicating through an axial passage I04 in the main valve stem 95 and valve head 91 with the passage 59 and inlet port 28. The needle I00 fits loosely that part of the axial bore 99 within the lower central boss 94 so as to leave an annular space I extending to the valve seat NH, and has a close slide fit in the upper part of the axial bore 99 so as to prevent leakage and extends beyond the upper central boss 93 and through a boss I06 on a pilot valve piston I01 reciprocable in the upper cylinder 9|, terminating above the boss I06 in a cone I08. The boss I06 has a pressed fit on the needle I00 so that the needle is actuated reciprocably by movement of the piston I01 and may be considered as functionally integral therewith.
Radial ports 0 in the lower central boss 94 connect the annular space I05 with the lower cylinder 92 above the main valve piston 96 to admit high pressure operating fluid thereto from the inlet port 28 when the pilot valve 51 is open. The main valve piston 96 has a skirt I I I grooved on its exterior surface with a helical groove I|2 which provides a restricted communication between the upper and lower faces of the piston. The cross-sectional area, hydraulic radius, and length of the groove IIZ provide a resistance to the flow of operating fiuid therethrough resulting in a pressure drop across the main valve piston 96 of determinable amplitude. The lower lining sleeve 90, against which the skirt I I I bears, has a plurality of notches or openings H3 in its lower rim communicating with an annular space ||4 between the lower rim of the upper casing member 41 and the head of the lower casing member 48, and the length of the skirt III is such as to leave the notches II3 unobstructed when the main valve 56 is seated and the skirt I I I is consequently in its lowest possible position. A vertical groove II5 on the inner surface of the upper casing member 41 extends from the annular space 4 to the head 49 of the upper casing member 41, forming a passage between the upper casing member 41 and the lower lining sleeve 99, the partition 88, and the upper lining sleeve 89, connecting with one of a plurality of notches or openings H6 in the upper rim of the upper lining sleeve 89, similar to the notches H3, and thus connecting with the upper cylinder 9| above the pilot valve piston I01. A radial passage I I1 through the upper casing member 41 connects with an annular groove II8 on the exterior surface of the upper casing member 41, and the annular groove I|8 communicates through a radially inclined passage II9 in the housing 2| with an annular groove I20 on the exterior surface of the control valve body 64 and thence through a radial passage [H in the control valve body 64 to the upper portion of the control valve chamber 69 above the plunger head 13. The acme thread 19 permits fluid communication between the upper portion of the valve chamber 69 and the annular space 11 around the control valve stem 15 whence, as already shown, there is communication through the radial passage 19 and longitudinal passage 18 with the lower face of the plunger head 13 and, therefore, with the discharge port 35. Sealing rings I22: seal the control valve body 64 relative to the walls of the chamber 62 above and below the radial passage I2I and below the annular space 61.
The upper cylinder 9| below the pilot valve piston I01 is in communication with the annular space 61 around the control valve body 64, and, therefore, with the upstream side of the metering orifice 14, by means of a notch I23 in the partition 88, an inclined radial passage I24 in the upper casing member 41, an annular groove I25 on the exterior surface of the upper casing member 41, and an inclined radial passage I29 in the housing 2|, all interconnecting. Sealing rings I21 are provided above, below, and between the annular grooves H8 and I25 to prevent loss and interchange of pressure.
The cross-areas of all the passages and grooves forming the fluid communication line between the lower cylinder 92, below the main valve piston 96, and the upper cylinder 9| above the pilot valve piston I01, and between the vertical groove IIii connecting these cylinders and the control valve chamber 69, are sufiiciently large to maintain substantially equalized pressures throughout the communication line, in view of the relatively restricted helical groove II 2 and the small volume of flow possible therethrough. Consequently, the fluid pressures upon the lower side of the main valve piston 96 and upon the upper side of the pilot valve piston I01 are substantially equal, and are less than the fluid pressure at the attested 7 main valve 56--or suhstahtiaiiy the pressure upon the-u stream side or the metering orifice H- when the main valve 56- is dpeh ty an amount equai to"; the pressure dropsthrough the pilot valve 51 and through the helical groove H2, and are; greater during dormer operation than the fluid pressure upon the downstream side 6f the meter ing orifice T4 by a'iiamodht e' uai to the pressuredrop' through the acme thread 16 'lhe fluid pressure upon the upper side 6f the inain velvepiston- 9 6 may equal the ressureat the main valve 56% thepilot va l've 51 is fully open, or may have some rower value; dueto pressure drop throu h the" pilot Valve 51 if that valve is partly closed, or may have a value decreasing" td the fluid pressure 1190f! the lower Side Of the fiiain valve piston- 9'6 if the pilot-valve 51 is closed. The fluid pressure upon the rower side of the" pilot valvepisto'n I01 is substantially the same as the pressure upon the upstream side of the metering orifice (4 any d i fier'ehcesbeihg qualized thr'ough the connecting elements I23} I21 I; and I16.
A spring I29 bearing upon the lower side of the maih valvep'ihfidli- 96 and tipbh the fewer casing member 8 acts in supplementation Of the flui'd pressure upon the lower side ofthe main valve piston 96' and of s'ufiicient" strength to overcome the ressure drop normally existent throughthe helicalgroove H2 and thustoh'old.
the main vaive 5'6 hermeuy open} As wiir be hereinafter showfi; the supplementary actionof the spring r29 may he overcome by increasing the pressure droptlirough thehel'ic'al groove II2 above normal, either by increasing the pressure above themain valve piston 9 5' or by decreasing or limiting the pressure therebelowl In a similar Way, a s'pring" I 36 acts upon the pilot valve piston I-ll-F but actsto urge the pilotvalve-to a closed position; The head 49ofthe upper casing member4 7 has a; recess I31- which receives a spring foll'ower I'3'2;' anda cup member I33; is loosely fittedover the BOSS M6 011 thpilbt" valve-piston I01 and has a conical recess: I34' to receive'and' bear against-the cone I 08 on the pilot valv'e needle IUOE The spring I 3'0 isnno'unted be-- tween the spring follower I3? and the yoke I-'3-3 so as to exert a downward; or'c'losing; forceupon the needle IOU. compensate" for changes in temperature in the operating fi ii'd; a manner hereinafter explained, the spring I-3Ii is of" hi metallic con'structio'n; having arr outer portion I35"having a relatively high coefiici'erit'of exp'an si'on, such as steel; and aninner portion I36-hav' ing'a relatively low coefi'icient ofexpansion, such as invar' metal, so that the outer portion I35 changes in length more rapidly than the inner portieh I36 with changes of temperature and tends to cause the spring tdv'v'i'nd up'jwith' increas ing' temperature and to unwind with decreasing temperature, and correspondingly-to increase and to decrease the-loading of and the forceexerted by, the spring. To allow for use of operating fluids of various-specific gravities, an adjustment screw I31 is-p'r'ovided inthe' head Mi -of the upper casing member H; having a conical point I38" whicli enga'gesa conical recess I39 in tlie spring follower I32, andhavin'g-a c'ap M0 which may be calibratediiiterms- Of= specific gravity (if the operating fluid. By turning the adjustment screw I31, thesprin'g follower" I 32-'ma y-be moved toimpart a greater or lesser initial loa'diii'g' tothesp'r'in'g" I 302 I operating parts; as best shown iiiFi'g's. 5 and 8} a dramagetdre its is; provided in the housing 2| aving a drain pipe; udsecuredto' its outer end by any suitable fittings and leading to any convenient pit er' receptacles, A valve 145', seated a bore Mtflof stepped diameter in continua tion of one of the main flow passages 1'0, opens arid doses communication between" tliat main flow' passage and the drainage bore I43' through a c'on'i-ie'c ting passage I41, and comprises a tap ho'dy I48 threadedly secured in the outer countertere of theb'or'e H 6 a valve stem I49, threaded irian' intermediate c'ounterbore of the bore I46 for movement t ereih, a ball [5t movable by the valvestein m to'clese the bore M6, and packing I m d n hressedty thevalve body ua.
lower cylinder 32 on the my pressure side of the mai'nvalve piston 96 is connected to the" space 52 between thelower casing member 48 thehpusin'g' 2Ifl by' an orifice I53 through the lower" easing member as; andthe space 52 is in turn cennecte'd' by a vertical passage I54, shown Fig; 5', to an auxiliary control passage I55 in the; lower portion or the housing m. The fluid pressure in the control passage I55 is, therefore, ndriiially the same as the pressure on the low pressure sides of the main valv'e piston 96 and the p-i-lotval-ve piston I 01 which are in fluid commuhi'cat'ion, as hereinbefore described. The outer eiid of the control; passage itsis provided with aswivel fitting I56 and pipe connections E57:- which may connect the control passage to a pressure gauge I58, and which are also adapted to connect thecontrol passage to a control device I59, shown diagrammatically in Fig. 8", of
\ either manually operated or automatically 013- erat'ed type; by which the operation of the control device may bestopped or intermitted;
A- pressure control valve I 60 is connected to thinner end of the control passage I55, as best illustrated in Fig.- 6; andcomprises a valve body IfBI threadedly secured ina' valve cylinder it! formedthehousing 21" and sealed therein by asealihgrin'g I 63; an adjusting screw I64 movably threaded inithe valve bod-y I61 and sealed there'- ih-hy'aseehng rihg'IGS and astufii'ng nut its, a
' nozzle threadedly" secured in the lower end ofthe valve body I-B I, and s'pring loaded' pressure' release mechanism i'nounted between the adust n'g sor ew' I-GE and the nozzle I6 1. The valve cylinder I62 communicates with the auxiliary con tr'plpassage- I 55 by means of a bore I68 in which the no'azle' IB-I is seatedto iorin a fluid-- tight joihtland witli the drainage bore I43 by a passage I-6'9. As-best shown in Fig. '7'; the nozzle I67 has an axial passage I10 and anaxial eX- teh's'ion FH- charnfered to terminate in a knifeedge valve seat I-I 2 annularly surrounding the passage 1:10; A n' optically fiat valve head 113', of
hard me 1- or sapphire; is held by a cap 1-1'4= vv-h-i'clihas a sliding fiton the axial extension Ifi l and ispressed against the valve seat I12 by aclip' us which fits loo's'elyover the-cap 114 and is backed by a spring- Ht? reacting against a spring follower IT'F positioned by the adjusting screw IS'fi". 'fo'cause ev'en wear upon the valve seat-ITf and thevalve'head H3- and to hold the variousparts in axial alignment, the cup l'l 5 has a" co'n'ie'al point" Wt" hearin against the rim of an axial dr n e 1T9 iri cap m and the adjusting screw Hi lhas a conical point I BO engaged bya moi'e'olotuse clinical recess I'B -I in the spring fell'o'w'e'i" ITI. A micrometer type th-i mlole I8 2 is sec'ured'td the'upp'efeiid' of" the adjusting screw itt by'e" set I as, to register with a calibrated skiit' itrseeui'e'd to the valve body it] By s 9 set screw I85. The thimble I82 and skirt I84 may be calibrated in pounds per square inch or any other convenient units.
The cap I74 has radial ports I86 at the level of the chamfered portion of the nozzle extension I'II admitting fluid which has passed between the valve seat IfZ and the valve head I13 to the interior of the valve body I6 I. A hole I81 in the valve body I6i communicates between the interior of the valve body and the valve cylin der I62 whence there is open communication to the atmosphere through the passage I69 and the drainage bore M3. By turning the adjusting screw to impart a loading to the spring I15, the pressure in the auxiliary control passage I55 may be limited to a desired amplitude, indicated by the micrometer thimble I82 and skirt I84, with surplus pressure being vented through the drainage bore M3.
An auxiliary utility connection is provided as shown in Figs. and 6 by a valve I92, similar to the drain pipe valve I45, in a vertical bore I9! which connects with a horizontal passage I92 communicating with the valve chamber 69 of the control valve as below the metering orifice 14. The horizontal passage I92 is closed at its outer end by a plug 93. A ball E94, movable by the valve id's, controls the flow of fluid from the vertical bore HM to a discharge port I95, threaded to receive pipe connections I96 leading to apparatus (not shown) which it may be desired to operate in conjunction with the fluid operated pump and at the same pressure as is applicable to the pump.
In the operation of my control device, the control valve 55 is opened to an extent at which it will pass operating fluid at a predetermined rate. The number of barrels per day of operating fluid supplied to the fluid operated pump or the strokes per minute which will result is indicated by suitable graduations on the micrometer thimble 82 and skirt 83.
It will be understood that the volume of flow through the control valve 65, at any given extent of opening of the metering orifice M, will depend upon the difference in pressures on the upstream and downstream sides of the metering orifice I4; and the calibration of the thimble 82 is made with reference to a certain pressure differential which be termed the normal operating pressure differential. Changing the setting of the control valve 85 so that the thimble 82 indicates an increased pump output of, say, 50 barrels, affects an increase in the opening of the metering orifice ill to permit passage of operating fluid sumcient to cause the pump to pump 50 additional barrels per day at the same normal operating pressure differential as previously existed. The operation will be best understood by referring to Fig. 8. The manifold section is connected to an adequate supply of fluid at a pressure in excess of that required to operate the fluid actuated pump to be controlled by the metering valve. The valve 23 in the manifold section 25 is fully opened to the inlet port 28 and as the main valve 56 is normally held open by the main valve spring I23, high pressure operating fluid flows from the manifold section 28 through the main flow passages iii and the metering oriflee M, impressing a fluid pressure diiferential across the latter. of this pressure differential is communicated to the lower, or high pressure, side of the pilot valve piston Iii! through the group of passages including the inclined passage I26, and the low pressure The high pressure componentv .tions. device is in a state of equilibrium which may be component thereof is communicated through the group of passages including the acme thread I6 to the radial passage Hi, the vertical groove H5 and the notches H6 and thence to the upper, or low pressure, side of the pilot valve piston I01, and through the notches H3 to the lower, or lower pressure, side of the main valve piston 96, and from the latter to the auxiliary control passage I 55 where it may be registered on the gauge IE8 or be limited by the remote control apparatus I59 or by the pressure control valve Ifit.
When the valve 23 is first opened, the pressure on the upper, or low pressure, side of the pilot valve piston It! is initially and momentarily less than normal because of the resistance imposed by the metering orifice I4 and the acme thread 76. The pilot valve spring I35 is adapted to withstand a pressure differential across the pilot valve piston Hi1 of slightly less amplitude than the normal operating pressure difierential across the metering orifice l4 and for the moment the pres sure differential across the pilot valve piston is excessive because of the low fluid pressure on the low pressure side of the piston. Consequently, the pilot valve piston Ill? moves upwardly and the pilot valve 51 opens and admits high pressure operating fluid to the upper, or high pressure, side of the main valve piston 96 through the group of passages including the passage I84. A pressure differential is thus impressed across the main valve piston 96 greater than the main valve spring I29 is adapted to withstand and the main valve 56 closes partly, at least.
' The main valve 56 now throttles the flow of operating fluid to the metering orifice 14 until the pressure differential thereacross is reduced to the normal operating pressure differential. In doing so, it reduces the pressure of the high pressure component of that pressure differential, which is also the pressure of the high pressure component of the differential across the pilot valve piston I01. At the same time there is a flow of fluid through the helical groove II2 to increase ;'the fluid pressure on the low pressure sides of the main valve piston 96 and the pilot valve piston Hll. Both of these actions tend to restore the pressure differential across the pilot valve piston I!" to the equilibrating amplitude at which the pilot valve spring is capable of holding the pilot valve 5'! floatingly between open and closed posi- When this is accomplished, the control termed the normal operating condition and in which the normal operating pressure differential across the metering orifice I' l impresses an equilibrating differential on the pilot valve piston I01, partly opening the pilot valve 51; and the .fiow through the pilot valve impresses an equilibrating differential on the main valve piston 96, closing the main valve sufficiently to permit a flow to the metering orifice Hi to impress thereon the normal operating pressure differential.
The equilibrating pressure differential across the pilot valve piston Ill! is created and transferred thereto by the normal operating pressure differential across the metering orifice M and has the same general magnitude and fluctuates in I close relationship therewith, varying from it only by the resistance of the passages connecting the two sides of the piston to the two sides of the orifice. The high pressure components of the two pressure differentials are virtually the same because of direct and substantially unrestricted communication through the radial inclined passage I26, and the low pressure components vary only by the pressure drop through the acme thread it. The pressure drop through the acme thread 16 is zero when the pilot valve 51 is closed or as soon after the closing of the pilot valve as the pressures at each end of the helix H2 are equalized; and it is constant whenever the system is in equilibrium, and the pilot valve is not moving. As the normal situations are those in which the pilot valve 5'! is either closed or in equilibrium, and as the degree of opening of the pilot valve required to increase pressure above the helix H2 is extremely small and, therefore, the flow through the acme thread is extremely light in volume, the pressure differential across the metering orifice Hi and across the pilot valve piston [9! either are equal or differ by a very small and normally constant amount and the difference may be ignored. Loading the pilot valve spring 39 so as to counterbalance a predetermined amplitude of one of these differentials in effect loads it to counterbalance a predetermined amplitude of the other.
The state of equilibrium, defined as the normal operating condition, will prevail until some circumstance changes the pressure differential across the metering orifice 14, when the pilot valve 51 and main valve 56 will move to establish a new rate of flow which will restore the pressure differential across the metering orifice '14 to its normal operating amplitude and so reestablish equilibrium. The pilot valve 51 will respond to increases in the pressure differential across the metering orifice 14 by increasing the extent of its opening and so decreasing the extent of opening of the main valve 56 and, conversely, will cause an increase in the extent of opening of the main valve 56 in response to decreases in the pressure differential across the metering orifice I4. Both actions are held to a rate of change suitable to a search for equilibrium, the one by the resistance of the acme thread 16 as the rate of flow therethrough increases, and. the other by the dashpot action through the helical groove H2 when flow through the pilot valve 51 is reduced or cut off.
As is best illustrated by the diagrammatic view of Fig. 8, the main valve piston 96 is in a flow channel which parallels the whole length of the main flow channel of the metering device from the inlet port '28 to the discharge port 35 and which, therefore, has the same over-all fluid pressure drop. In this respect, the invention differs materially from devices of similar function in which operation of the main valve is effected by control members situated in a flow channel which parallels only the main valve itself, these control members in turn responding to a pressure differential across a metering orifice. Devices of the latter type are well adapted for use under conditions permitting employment of an automaticall variable metering orifice which will apportion to itself a quantitatively constant part of the over-all pressure drop across the metering device, thereby assuring creation of a constant force with which to actuate the control members. But with a metering orifice, as in the present invention, designed to be set as to permit a very accurately controlled predetermined rate of pumping independent of the magnitude of the pressure differential across the entire valve and with large possible variations in this overall pressure drop, the forces required to operate the main valve may be largely due to both friction and unbalanced areas. It is, therefore, de-
sirable under some conditions. to have the pres- 12 sure differential across the main valve piston 96 potentially the over-all pressure drop and to utilize such portion of the over-all pressure drop as is necessary to actuate the main valve.
It will be appreciated that the temperature and, therefore, the specific volume of the operating fluid may vary considerably at the control device but that by the time the operating fluid has reached the pump at the bottom of the well, the temperature and specific volume will have been brought to a prevailing constant. Oil, which is used as operating fluid, changes in volume in direct relation with temperature and, therefore, when the temperature of the operating fluid at the control device is high, in relation to a constant, the control device must permit passage of an increased volume in order to obtain at the pump a volume constant in relation to the constant temperature there prevailing. The bimetallic pilot valve spring 130, as heretofore explained, winds up, so as to increase in strength, with an increase in temperature, which is imparted to it by the operating fluid flowing through the control device, and so holds the pilot valve 51 slightly more closed and, consequently, causes the main valve 56- to open slightly wider for a given pressure differential across the metering orifice 14. This is the equivalent of increasing the normal operating pressure differential across the metering orifice 14 and the related equilibrating pressure differential across the pilot valve piston 10'! with an increase in temperature of the operating fluid so as to require a Wider opening of the main valve 55 to produce an equilibrating rate of flow. Thus, the bimetallic spring I38 serves as a thermostat means for automatically shifting the level at which the pressure differential across the metering orifice 14 is maintained, the pressuredifferential level varying directly with temperature, or inversely with specific volume. It permits a production-volume setting on the micrometer thimble 82 at any temperature to indicate accurately the production volume at all temperatures in an expectable range.
In a similar manner, operation of the adjustment screw [3! permits an accurate indication of the production volume coupled with the use of operating fluids of various specific gravities. If the specific gravity of the operating fluid was above normal, the pressure differential across the metering orifice 14 would also be relatively high and, if this pressure differential were higher than the normal operating pressure differential, it would cause opening of the pilot valve 5'! and thereby closing of the main valve 55; and, thereafter, when the pressure differential has been restored to the normal operating amplitude, the operating fluid flowing through the control device would have less volume and less productive capacity than was indicated by the micrometer thimble 82. The adjustment screw [3! would, under these circumstances, be turned inwardly to increase the loading on the pilot valve spring I38 and thereby to increase the level of the normal operating pressure differential at which the pilot valve 51 and main valve 56 are held in equilibrium. With the main valve 55 held open to impress upon the metering orifice 14, the new, and higher, normal operating pressure differential, the same volume of operating fluid will fiow through the control device as with a lighter fluid, a lighter spring, and a lower normal operating pressure differential. The adjustment of the screw I31 can, therefore, be calibrated directly in fluid gravity so that the control device may 13 be set for the kind of fluid that is passing through it.
A maximum limit on the pressure in the control passage Hi5 may be imposed by the pressure control valve Hit, and as this passage communicates with the low pressure sides of the pilot valve piston ld'i and the main valve piston at and also with the low pressure side of the metering orifice i l through the acme thread it, the pressure at all three of these points may also be limited. If it is desired to limit the pressure in the supply line from the control device to the fluid operated pump to a certain maximum, the spring I76 is loaded appropriately by adjustment of the adjusting screw I54, with the micrometer thimble Hi2 indicating the allowable pressure. When that pressure has been attained, surplus pressure will be vented to the atmosphere through the drainage bore Hi3, and the low pressure components of the operating pressure differential across the metering orifice a l and of the equilibrating pressure differentials across the pilot valve piston is? and across the main valve piston 86, will be held to the desired limit. Any further increase in the high pressure components of the pressure differential across the metering orifice l6 and the pilot valve piston lfil, which are of the same mag nitude, will extend these difierentials beyond their normal and equilibrating amplitudes and so cause the pilot valve El to open and to cause a closure of the main valve 5E. It will be seen that the main valve is made abnormally sensitive to closure by the limit imposed on the fluid pressure against the low pressure side of its piston 96 and that any material flow through the pilot valve at will cause closure of the main valve. The pilot valve Will be held in an equilib rium permitting only a small amount of flow therethrough and, as only this flow can reach the pressure control valve lite and part of it will pass through the acme thread it, there will be very little waste to th atmosphere. The action of the pressure control valve ltd effectively cuts off the supply of operating fluid and stops the fluid operated pump if, for any reason, the pressure at the inlet port 2s continues to rise after the pressure at the discharge port 35 has reached the limit imposed by the valve.
The pump may also be stopped or otherwise regulated by control devices connected to the auxiliary control passage i525 through the pressure gauge pipe connections i5l. For example, if it should be desired to operate the pump intermittently to allow the well to fill or a receiving tank to empty, a timing device may be employed to open the pipe connections 65? to low pressure at intervals as required, and such a device may be stationed remotely at a convenient central. control point from which a group of Wells may be controlled. Opening the pipe connection iii? to low pressure will at once upset the equilibrium on the pilot valve piston it"! and the main valve piston 95, causing the pilot valve 5? to open and the main valve to close, but the loss of operating fluid Will be limited. to the small amount passed by the pilot valve as further restricted by flow through the helical groove H2.
Various devices may be connected to the pipe connections I98, as shown in Figs. 1 and 2, so as to draw operating fluid from the low pressure side of the control valve t5 and to operate in parallel with the fluid operated pump and such devices may be operated at the same pressure as the pump or at a lower pressure, provided the supply line thereto is furnished with suitable 14 pressure control mechanism; and their operation will not interfere with the operation of the control device, as their fluid take-on point is no more closely related to the pilot valve system than is the fluid take-01f point of the pump itself.
Various modifications in the arrangement of the cooperating parts of my invention will be apparent to one skilled in the art and such modifications do not depart from the spirit of my invention, nor do changes in areas and resistances altering the pressures of equilibrium as may be desirable to adapt my invention to various usages. Consequently, I do not intend to be limited to the specific embodiment shown and described, but desire to be afforded the full scope of the following claims.
I claim as my invention:
1. In a control assembly for a fluid flow governor, the governor including a housing having an inlet, an outlet, passage means connecting said inlet and said outlet, and a metering orifice in the line of said passage means, the combination of: a sub-housing securable in the housing and readily removable therefrom, said sub-housing' providing a first chamber and a second chamber; a main valve piston disposed in said first chamber; a'pilot valve piston disposed in said second chamber; mean carried by said sub-housing and forming a main valve seat Which extends into the line of the passage means between the inlet and the metering orifice when said subhousing is secured in the housing; main valve means connected to said main valve piston and movable into seating engagement With said main valve seat to control the flow of fluid therethrough; pilot valve means connected to said pilot valve piston and disposed in a passage from the inlet to one side of said main valve piston, the other side of said main valve piston being exposed to the fluid pressure in the outlet; and means connecting said second chamber across said metering orifice to apply the fluid pressures on opposite sides of said metering orifice to opposite sides of said pilot valve piston.
2. In-a device for regulating the flow of a fluid, the combination of: a main passage for the fluid; a pilot passage communicating with said main passage; means in the line of said main passage for producing a fluid pressure differential; pressure-actuable pilot valve means in the line of said pilot passage and exposed to said fluid pressure difierential for regulating flow through said pilot passage; pressure-actuable main valve means in the line of said main passage and exposed to pressure variations resulting from variations in the flow through said pilot passage for regulating flow through said main passage; pressure-limiting means forlimiting the low pressure component of said pressure differential to a. predetermined maximum value; thermostat means acting on said pilot valve means and exposed to the temperature of the fluid for compensating for variations in said fluid pressure differential due to variations in the specific volume of the fluid; and adjustable means acting on said thermostat means forcompen'sating for variations in said fluid pressure dif- 'ferential due to variations in the specific gravity of the fluid. s
3. In adevice for regulating flow of a fluid, the combination of: a main passage for the fluid; 'a pilot passage in parallel with said mainpassage; pressure-actuable main valve means in the line of said main passage an actuable by a main pressure differential for regulating fluid flow through said main passage; means in the line of said main passage for producing a pilot pressure differential; means in the line of said pilot passage, including pressure-actuable pilot valve means exposed to said pilot pressure differential, for producing said main pressure differential and for applying it to said main valve means; and pressure-limiting means for limiting the low pressure components of both of said pressure differentials to predetermined maximum values.
4. A device according to claim 3 including passage means connecting said main and pilot passages for substantially equalizing said low pressure components.
5. In a device for regulating flow of a fluid, the combination of: a passage for the fluid; means in the line of said passage for producing a pressure differential; pressure actuable valve means including a pilot valve exposed to said pressure differential and including a main valve in the line of said passage for maintaining said pressure differential substantially constant relative to a predetermined pressure-differential level; and thermostat means operatively connected to said pilot valve for shifting said pressuredifferential level in inverse relation to variations in the specific volume of the fluid resulting from variations in the temperature thereof so as to maintain substantially constant the ratio of the volumetric rate of flow of the fluid through said passage to the specific volume of the fluid.
6. A device as defined in claim 5 including manually adjustable means acting on the means last defined in claim 5 for shifting said pressuredifferential level.
7. In a device for regulating flow of a fluid, the combination of: a main passage for the fluid; a pilot passage in parallel with said main passage; means in the line of said main passage for producing a fluid pressure differential; pressureactuable pilot valve means in the line of said pilot passage and exposed to said fluid pressure differential for regulating flow through said pilot passage; pressure-actuable main valve means in the line of said main passage and exposed to pressure variations resulting from variations in the flow through said pilot passage for regulating flow through said main passage; and thermostat means exposed to the temperature of the fluid and cooperating with said pilot valve means to move said main valve means toward its open and closed positions in response to increases and decreases, respectively, in the temperature of the fluid.
8. In a device for regulating flow of a fluid, the combination of: a main passage for the fluid; a pilot passage in parallel with said main passage; means in the line of said main passage for producing a fluid pressure differential; pressure actuable pilot valve means in the line of said pilot passage and exposed to said fluid pressure differential for regulating flow through said pilot passage; pressure-actuable main valve means in the line of said main passage and exposed to pressure variations resulting from variations in the flow through said pilot passage for regulating flow through said main passage; and thermostat means acting on said pilot valve means and exposed to the temperature of the fluid, said thermostat applying an increasing force to said pilot valve means with an increasing temperature of the fluid.
9. In a device for regulating flow of a fluid, the combination of a main passage for the fluid; an auxiliary passage in parallel with said main passage; means in the line of said main passage for producing a fluid pressure differential; a main valve in the line of said main passage and movable between open and closed positions for regulating flow through said main passage; displaceable fluid separating means connected to said main valve for moving it between its open and closed positions; means providing fluid communication between opposite sides of said fluid separating means and spaced points in said auxiliary passage; and valve means actuable by said pressure differential for regulating flow through said auxiliary passage.
10. In a device for regulating flow of a fluid, the combination of: a main passage for the fluid; a parallel pilot passage communicating with said main passage at two spaced points; means in the line of said main passage between said points for producing a fluid pressure differential; pilot valve means in the line of said pilot passage and actuable by said fluid pressure differential for regulating flow through said pilot passage; and main valve means in the line of said main passage between said points and movable between open and closed positions in response to variations in the flow through said pilot passage for regulating flow through said main passage.
11. In a device for regulating flow of a fluid, the combination of: a valve, metering means in series with said valve for producing a pressure differential; means responsive to a proportion of the difference in pressure across said valve and said metering means for actuating said valve; and means actuable by and exposed to said pressure differential for regulating the proportion of said difference in pressure applied to said valve-actuating means.
12. In a device for regulating flow of a fluid, the combination of: a main passage for the fluid; a pilot passage communicating with said main passage at two spaced points; means in the line of said main passage between said points for producing a fluid pressure differential; pressureactuable pilot valve means in the line of said pilot passage and actuable by said fluid pressure differential for regulating flow through said pilot passage; passage means for applying said fluid pressure differential to said pilot valve means; and main valve means in the line of said main passage between said points and movable between open and closed positions in response to variations in the flow through said pilot passage for regulating flow through said main passage.
CLARENCE J. COBE'RLY.
References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,685,205 Stein Sept. 25, 1928 1,745,059 Rush Jan. 28, 1930 1,787,686 Kerr Jan. 6, 1931 1,813,122 Moore July 7, 1931 2,035,472 Hammond Mar. 31, 1936 2,102,865 Vickers Dec, 21, 1937 2,139,050 Vickers Dec. 6, 1938 2,227,297 Coy Dec. 31, 1940 2,258,878 Bassler Oct. 14, 1941 2,468,416 Stresen-Reuter Apr. 26, 1949