CA1175897A - Pump failure protection for liquid transmission pipelines - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
The present invention provides a battery condition indicator for use in a circuit comprising a DC power supply connected across the terminals of a nickel cadmium battery, comprising: (a) a branch connection to the positive side of the power supply; (b) a second branch leading to the negative side; (c) four transistor circuits arranged in parallel, the first three of which have their emitters connected with said positive branch, the fourth being reversed with its emitter connected with the negative branch; (d) the second transistor having its plate connected with the collector-to-green LED
circuit of the first transistor; (e) a fourth transistor with a negative emitter circuit between the negative branch and the emitter; (f) a zener diode having a connection from the negative emitter circuit of the fourth diode through said zener diode with the base of the first transistor with a re-sistor between the zener diode and the base of said first transistor; (g) a shunt circuit around said resistor wherein the base of the third transistor is connected through a resistor to the connection leading from the zener diode to the base of the first transistor at a point between the zener diode and the resistor in said connection, the collector circuit of the third resistor being also connected to the connection between the zener diode and the base of the first transistor but joining said connection between the said resistor in said connection;
(h) the said circuits being so arranged that a normal charging current path will put a negative bias on the base of the first transistor to light the green LED, thereby extinguishing the red, but lighting the red if the green is extinguished, and under normal voltage lighting the red by an absence of adequate negative voltage in the base of the first transistor, and the lighting of the green by the application of adequate negative voltage through the zener diode circuit to bias the first transistor, the green LED being extinguished when the charging voltage is above normal by the positive voltage from the collector of the third transistor offsetting the negative flow from the zener diode, but by reason of the resistor in the connection between the zener diode and the base of the first transmitter enabling the zener diode to continue to supply a negative bias to the base of the third diode.

Description

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This pxesent invention relates to the transfer of liquids, most commonly water and sewage lines where liquids .in large volumes are pumped from a lower to a higher elevat:ion through'reIatively long pipelines. In these and other similar systems heavy damage may resul~ where ~here is a:n unexpected power ~ailure or mechan~cal breakdown of a pump.
This application is a divisional application of co-pending application No. 374`,460 filed April .2, lg81.
Generally, and almost exclusively, pumping systems of lQ the kind to which'this invention is applicable employ more than a ~ingle pump and usually more than two pumps i.n pàrallel to meet' variable'output demands or input supply but keep uni~orm pressure'in the'pipeline, which is pre~erable to a single large pump, ~ut this invention is applicable to systems having one or more'pumps. The expression "last pump" in the case of a system having only one pump will apply to the single pump, and also the use'of the plural "pumps" may mean such single pump.
~ here the system is operating normally and for ~some reason the pump or the last pump stops, there is an initial drop in press-ure'in the pump header as the ~arge volume of liquid ahead continues to move through the pi'pe but the loss of pressure'sets up a shbck wave ~hat travels through ~he liquid at the speed of sound in water, that is, around 4000 feet (120Q~
meters) per second. Reaching the remote terminal of the pipe-line,',a pressure wave'returns, often of destructive force, ~hich may damagP'the 'pipeline and its supports or break the ~umps~ 'For this reason it is the usual practice to connect ~ ~urge'~al~e'into the he'ader ~t l 17~&') 7 the pump;ng station arranged to open whcn such failure of ~he pumps occurs.
Generally, a surge valve has a valve closing thc inlet to the valve cas~ng while the easing has a normally unrestricted outlet. ~he valve ~lement ~s sli.dable in the vaLve chamber with its end remote from the seat of larger area l:han ~ts seat on the inlet, this end of larger area being exposed to ~he interior of a pressure chamber wh~ch also communicates wi~h the pump header. As long as ~he pressure ln the pressure chamber is equal to the O header pressure tendi.ng to open the valve, the valve wi.ll remain elosed or seated because o the larger area i.n the pressure chamber. If the pressure drops in the header, a pilot valve wlll operflte to release the pressure in the pressure chamber to atmosphe~ic pressure whereupon the valve will lift from its seat and allow a free outflow of water from the heacler through the surge valve and pipellne to waste, thereby proteetirlg the pump and pipeline rom the impact o the pressure surge. Heretofore a hydraulic pilot valve was provide~ to open the surge valve when the unscheduled stopping of the pumps reduced hydraulic pressure O in the surge valve pressure chamber.
A drawback to this arrangement is tha.t in a very long pipeline the hydraulic pilot valve will open wPll before the return surge reaches the pumping station where, in other cases and with shorter pipelines, the surge may return before the hydraulic pressure valve will have opened suf~icien~ly to effect full opening of the surge valve, or perhaps no opening of the surge valve will have happened whereupon the surge valve was unprepared to meet the pressure surge ;.n time to effecLively efFect the desi.red rel~ef, althou~h a pressure r~lieE valve was also provided.
It has heretofore been proposed to replace the hydrau-lic pressure relie~ valve above referred to with a solenoid . operated relief valve for openi.n~ the surge valve and to suhstitute a ~ressure swltch that will energize the solenoid ~5 valve to open fully almost instantaneously when Lhe pump di.s- j charge pressure lowers due to sudden ahnormal shutdown of pump but which, of course, does not happen with the ~radual eontrolled shutdown of the pumps.

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The present invention utilizes such a solenoLd and pr~ssure switch but in conjunctlon w~th a control clrcuit means desi~ned, but no~ necessar~ly required, to bc contained wlthin a single convenlently located box or hous~ng and ar~anged to anticipate the pressure surge ~nd ~s~ure the surge valve beln~7 open at the r~quired tlme and to effect gradual closl.ng of ~he surge valve after a predetermine~ time interval acle~uate for the surge valve to have relieved the pressure surge. This control circui.t means is energ~zed from the same power source as the 0 pumps but ~ncludes a battery which functions lf the power to the pumps fails 9 utili.zin~ a unique battery charging olrcui~ with a nickel cadmium battery and ~ battery condition indiccltor that will keep the operator lnformed as to the battery anl charger conditlon and even pro.vide warning of a blown fuse or de~ectlve lS circuit or battery. Ad~ustab1e t~me delay rPlsys i.n the clrc-~lt sequences operation~, a& here~nafter described in detall, and ln s~ch manner tha~ a~ter there h~a b~en an operation o the surge valve and the circuit i6 about to re-arm l~.self or the next emergency, and with the ~estoratlon of power to the clrcult, only a light emitt~n~ d~ode on the battery conditlon lndic~tor wiLl .show a ~ight, - If, at this time, the pressure swltch for the surge valve should ~e closed bu~ no pump should be operating, an amber panel light w~ll start flashing. l now a pump ls started, the amber panel light will stop flashing

2~ and remai.n constantly lit.
The starting of the pump or pumps will result in ~he first tlme delay relay starting to run. At the preset time ~nterval a control relay will de-ener~lze the amber panel light and a green panel light wil? be steadily lit. The elapseo time to thls point wlll ordinarily delay the lightin~ of the green light for sufficlen~ time that minor startup pulsations which could resul~ in opPnin~ the pressure switch ~which will previously have been closed by ~he he~d of water remaining in the pipeline after the brief opening of the surge valve) w~.ll be ineffective rO
cause a surge valve opening. Vsually a ~imer allow5.ng a per~od up to 300 seconds will be adequate ~or this st~rtup.
The "timing out'l of the first time delay relay at this point establishes a c~rcuit to a~second time delay relay which in its initial condltion will haYe no ~mmediate effec~, but if there -- . . . .

1 17r~39 i~
is a power failure or an opening of the pressure switch for some other cause, the first time delay relay lose~ its ground or negative circuit, establishing a circuit through the solenoid switch t'o cause opening of the surge valve, extinguishing the green panel light, lighting a red panel light warning that a pressure.surge'is to be anticipated and sett:ing in motion time delay relay No. 2.: This assures that the su:rge valve will remain open ~or a predetermined per~~od of time. At the end of this time, time delay relay No. 2 will de-energize the circuit complet~ly. This will also open the c.ircuit to the control xelay which, howaver, will not occur immediatelY due to an off-. delay. de~ice, including a capacitor that will de}a~ suchopening o~ the'circuit Eor perhaps 30 seconds.
Provision is made for manually closing the valve from the outlet header of the pump to the surge valve and a push button switch, in series with the pressure switch may open the cixcuit as if the pressure switch had opened and thereby put the circuit through a test run, which will even trip the solenoid .Yalve s~itch'and open said valve and also test the panel :Light 2~ sequence.
. Ihe inYention further provides a solid state flasher circuit and unique `solid state battery'condition indicato:r . .
and a battery charging circuit.
.According to the present invention therefore there is provided a battery condition indicator for use in a circuit - comprising a DC power supply connected across the terminals of a nickel cadmium battery, comprisingo (a) a branch connection to thè positive'side 'of the power supply; (b~ a second branch leadin~ to the negative'side;: (c) four transistor circuits 3Q. ~rranged in parallel, the first three of which have their emitters connected with said positive branch, the fouxth being reYersed with its emitter connected with the negative br.anch;

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I L 75~97 ~d) the second transistor having its plate connected with the collector-to-green LED rirCuit of the first transistor; (e) the fourth transistor with a negative emitter circuit between the negative branch and the emitter; (E) a zener diode having a connection from the negative emitter circuit of the fourth diode through.'said zener diode with the base of the fir~t transistor with a resistor between the zener diode and the base'o~ said first transistor; (g) a shunt circuit around said xesistor wherein the base of the third transistor is connected lQ through a resistor to the connection leading from the zener diode to the base of thè irst transistor at a point between the ~ener diode 'and thè resis~ox in said connection r the collector circuit : of the -third res'istor ~eing also connected to the conr-ection between the ~ener diode and the base of the first -t:ransistor but joining said connection between the said resistor in said connection; ~h) the said circuits being so arranged that a normal charging current path will put a negative bias on the base of the first transistor to light the green LED, thereby extinguishing the red, hut lighting the red if the green is extinguished, and under normal voltage lighting the red by an absence of adequate negative voltage in the base of the first transistor, and the lighting of the green by the application of adequate negative voltage through the'zener aiode circuit to ~ia~ the first transistor, the green LED being extinguished ~hen the charging voltage is above normal by the positive .yoltage from the'collector of the third transistor offsetting th.e negative flow from the'zener diode, but by reason of the xesistor in the connectiGn ~etween the zener diode and the ~ase of the first transmitter enabling the zener diode to continue tQ supply a negative bias to the base o~ the third diode.
In the'accompanying drawings showing one pre~erred embodiment of our invention with'a solid state circuit capable - 4a -117r)~9 7 of being containedr i desired, in a single enclosed metal box:
Fig. 1 is a more or less schematic view o pumping station surge val~e and controls t Wi th a mult:iple pump arrange-ment;
~ g~ ~ is a block diagram o the various circuit co~ponents;
Fig. 3 is a sch~ematic solid state circuit diagram ~ith certain duplications of some elements to avoid confusing cxoss-wiring;
la Fig. 4 is a schematic circuit diagram of the power ~uppl~ circuit;
Fig. 5 is a schematic ~.iew of the flasher circuit;
Fig. 6 i~ a schematic view of ~he "OEf-Delay"; and 3Q.

i - 4~ -1 17~8~'37 Fig. 7 is a schematic view of the "Battery ConditLon Indi~ator."
~ ig. 8 is a fragmentary detail view for use in a pumping station with a check valve in the pump out~e~ and mean~
to prcvent closing of the surge valve before the check valve has closed.
Fig. 9 is a circult diagram slmil,ar to Fig. 3 but with one ~imer ha~ing a circult arranged for long pipelines between the pump and the discharge terminal.
Fig. 10 i~ a schematic view of a compound switch arrangement for use with Fig. 10.
In the following description all reerence characters preceded by the capital l~tter D refer to diodcs which are con-ductive` in the direction o the pointed electrode or arrow. All S relay contacts are indicated by parallel lines~ but where the contact~ are closed when the circuit is ready for start-up, they are crossed by a diagonal line. To distingui~h from capacltors, one of the two confronting lines of a capac~tor ~s slightly curved. Time de~ay relay terminals for the number 2 time delay

3 relay are designated TDR-2 followed by a circled number9 as TDR 2 , where the circled number is a manufacturer's designation, whereas reference numerals having no circle are in the tradi-tional designation where an uncircled reference character is an albitrary designation~ In some cases, to avoid complexlty of e~rc~i~ lines, the same part, as for example TDR-2 ~ , will appear at different locations in the diagram. This is understood in solid state circuit diagrams.
Also in th~s ~pplication, reference to operations relates to abnormal conditions, such as mechanlcal brea'kdown or ) loss of power to the pumps; and not to the normal shutdown of a station where the shutdown is controlled in such gradual manner as to a~oid surge produc~ng conditions in the pipel~ne.
Referrin~ ~irst to Fig. 1, there is here schematically shown a surge valve inst~llatlon for a pumping statlon havin~ one or more electrically driven pumps P. In the d~agra~ three pumps are indicated, all discharging liquid to be transported to a common header. Depending on the demands of the system, one or more pumps are normally operating to force l~quid from a source of supply, not indicate~, into the header ~o entler the pipe . ' ' ~

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throu~h which the liquid wlll ultimately be conveyed to a remot~
point of discharge elevated above the level of the pumping stat{ on.
The su~ ge valve ltsel f i5 a known and widely used i device having an ~nlet A which, in this instance, is connected to the header through a manual~y operable shutof~ valve B. Thc inlet opens into a chamber C wlth an outlet D. A v~lve element E i~
arranged to open or close the inlet A and the upper end of this valve element is located in a separate chamber F, the valve ) having a sllding fit in the body o~ the valve. The upper end of the valve element has a larger efective area than the lower end.
Fluid from the header enters the chamber F through pipe G and needle valve G' and, as long as the pressure in the upper chamber is as great as the pressure in the inlet A, the different~al area will keep the valve element seated and the valve wlll reman closed.. If the pressure in chamber F drops below the in~et pressure under the valve element E, element E will be lifted from its closed posit~on~ openin~ t~e inlet to 10w freely through the valve body to the outle~.
As long as one pump is operatin~, normal pressure will prevail in the header; but, if there be but one pump or any of a multip~e number of pumps stops under abnormal circumstances as previously explained, there w~ll be a drop in pressure in the S header which will close a circuit through which the solenoid valve J will be energized to relieve the pressure in ~urge valve chamber F to open the surge valve, and if there is an over-pressure in the header, the overpressure valve will be directly opened by the ope~ing of overpressure valve K to relieve the '3 pressure ln chamber F.
The needle valve G' provides for the gradual restora-tion of pressure in chamber F when normal condi.tions returnO
This invention is primarlly concerned with the electr~-. cal equipment involved in operation of the solenoid valve J, the5 startup and operation of the pumps, the overriding o~ the operation of the soleno~d whenJ after an abnormal or unscheduled shutdown of the pumps, operatlon is restored and ~ndlcating the condit~ons of the control ciruits at all times, including delayed open~ng of the surge valve for a preset time~ g~ving of advance 0 warn~ng that the circu~t is prepared or armed ~o effect delayed - ~- ', .

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openinq, and other features, as will hereinafter appear. The electrical equipment is especially designed to be incorporated in a sinqle wall-mounted box as a single unit but may be divided into sections, some of w}-ich would be housed separately from others and interconnected. ~n either case, this equipment will be hereinafter referred to, both in -the description and the claims, as the "box". The box need not be in immediate proximity to the pump itself but located at the attendant`s station which is usually nearby, but it may even be somewhat remotely located from the pumps; but preferably, though not necessarily, it is where an attendant can have ready access, in case oE ncect, to the ~ mp, and the box is connected to the power supply Lines to the pump or pumps in -the imrnediate vicini-ty of the pumps, that ls, assum-ing the pumps to be electrically driven.
Fig. 2 is a block diagram of the box in which each block contains equipment, as indicated by the printed legend in the block. The box operates from a standard 120 volt, 60 cycle alternating current (AC) power source, which in this case is common to the power source for driving the pumps of the pumping station. The "Battery Charger" converts the AC to 24 to 34 volt direct (DC) current and supplies it to the storage battery, which is desirably a nickel cadmium battery that "floats" or is at all times connected across the battery charger output lines. The square marked "BATTERY COND" controls the selective operation of red and green indicator lights, as hereinafter described.
The following block marked "Mode" includes a manually operable switch which selects which of two procedures is the better suited for a particular station or under some certain con-- dition. There follows a flasher unit that is energized under certain conditions only when a flashing green or arnber light should be displayed by electric lamps GL or AL in the upper right corner of this figure. Next to the flasher there is an "O-Ef 1 l75~3(3i~
Delay" relay above which is relay CR-l. To the le~t of CR-l there is a first tir,~e delay relay TDR-l and above this is TDR-2.
TDR-2 is the .last of the severa:l blocks in -the diac~ram, but it will be observed that out of 'rDR-2 are two :L:ines 5 and 6 which are the box terminal.s of l.:ines 5 ancl 6 o:E the solel-loid valve J of Fig 1. Also to the left o:E TDR-l are lines 3 and 4, these being the box -terminals of lines 3 and 4 of the pressure switch PS of Fig. 1. There are two other terminals 7 and 3, these being the terminals of the powex supply lines 7 and 8 of Fig. 1.
While designated as power supply lines, they are actua:Lly lines to the starter switches of the purnps P; but since they open when a pump stops and are closed when a pulnp starts, ~hey m.ly be referred to a power indicating lines or au~iliary motol: startc:r con-tact lines.
Coming now to the explanation of the actual circuit, the first two blocks of Fig. 2 are combined in the square marked "Power Supply" in Fig. 3, the 120 volt AC input lines of which are designated 120 AC. The positive 24-34 volt DC output is designated by line 10 that extends from the positive terminal of the power supply downwardly, then across the diagram in Fig. 3 and then up to the positive terminal of the battery. A fuse is indicated in line 10 at lOa close to the battery. Line 10 also includes diode D-13, which alIows the flow of direct current through line 10 toward the battery .
but not in the reverse direction, that is, from the battery back to the power supply. It may be here pointed out, since the circuit includes a multiplicity of diodes, the "point" of the arrow indicates the direction of current flow, but that current may not flow in the reverse direc-tion, this being the common practice in the diagraming of solid _ state circuits. The negative terminal of the DC power supply is inidcated by the conventional ground indication, and there is a return line from the negative pole of the battery and line 12 to ground, as indicated at 13.
A branch line 14 leads from line 10 at point l~a between 'J/~
diode D-13 and the battery and terminates at relay contact 15 of the control relay CR-l, the outline of this relay ~einCJ indicated as a block in Fiy. 2 and in broken lines in F:ig. 3. Contact 15 is open at this point. Opposite or above contact 15 there is indicated ano-ther pair of contacts 15' of a single pole, do~ble throw relay which are never used. It has previously been ex-plained that throughout the diagram the contacts indicated only by spaced parallel lines are open, but they are closed when crossed by a diasonal line.
There is a branch line 16 leading from the positive side of the power source to contac-t 17 of time clelay ~elay TDR-l (also outlined generally as a rectangle in broken lines). It is a standard piece of e~uipment available as an oE~-the-shel~ icem and per se is not of our invention. :tt may be purc}-ased, for example, from TKS Engineering Cornpany of ~innetonka, Minnestoa.
In addition to contact 17, this relay has contacts 18,19 and 20.
The timing circuit represented by 21 is the relay coil, and there is a one-way shunt circuit with diode D-22 across its terminals.

There is a positive biasing voltage connection leading from the positive side of the power source through line 23 in which is resistor 24 to the base of a transistor 25 conventionally indica-ted with a base, a collector and an emitter.
As here diagramed, the emitter of the transistor leads to mode switch 26 that connects to both one side of the coil 21 of the relay and the input side of diode D-22.
To explain further what may be termed the positive (+) side of the circuit, at all times when the power source is energized there is a branch connection 27 from line 10 between _ the battery and the power source with one lead 28 leading to terminal 7 of the pump circuit, as explained in Fig. 1. Another lead from 27 is connection 29 including diode D-30 leading to the flasher portion of the apparatus, which in Fig. 3 is represented 1 17~8() 1 by the block "FLASIIER", an opposite terminal of which connects through line 31 to ground or negative at 13.
A line 32 leads from the flasher to connector 33 having a branch 34 leading through contacts 35, here indicated to be closed, to conductor 36 leading to one side of an amber Li~ht 37.
Another pair of contacts leading from flasher connection 32 and the other branch o~ 34 is indicated at contacts 38~39 in line 40 connected with one terminal of a green electric lamp 41.
Another element at all times included in the circuit is the battery condition indicator uni-t 42 connected at one side to connection Z and the other side to ground through TDR-Z COll~ lCtS
(~ - ~ and by which red and green light emi-t-ting diodes (I.ED), generally desiqned for mounting on the door of a box, are energi~ed, these being separate, of course, Erom pilot lamps 37 and 41 and also the red lamp hereinafter referred to, which are also, but not necessarily, mounted on the door of a box.
Further considering Fig. 3, the principal negative side of the circuit, starting with ground 45 at the right of the dia-gram, this part of the circuit comprises TDR-2 closed contact 46 across terminals or pins ~ and ~ across normally closed push-button circuit testing switch 47, across pressure switch contacts 3 and 4, here shown in closed position, to line 48 with a branch connection to the other terminal of am~er light 37 and another to the second terminal of green light 41. Line 48 then extends to branch 48a which includes diode D-49 connected with the emitter of transistor 25. Another branch of 48 leads through connection 48b to the open-terminal of mode switch 26. Line 48 also extends through line 48c including resistor 50 that balances similar resis-_ tor 24, both circuits thus leading to the base of transistor 25.
At this point, consideration may be given to the opera-tion of the circuit. Assuming the pump or pumps to be driven from a usual AC current source, then for the box to become armed and ,~, -- 10 --5~
initiate the timing sequence, 120 volts AC must be supplied to the input lines of the power supply, and in the case here showrl, this should be derived from a power source common to that which drives the pumps, or in some cases just one pump, at the p~lrnping station. There should be sufEicien~ pressure in the Manifold by reason of the back pressure of liquid s-till remaining in the pipe-line after closing of the surge valve to close contacts 3 and 4 of the pressure switch PS and the circui-t should be closed across the terminals 7 and 8 by the auxiliary motor starting contacts when the pumps are started.
If there is no AC voltage applied to the power input lines of the power supply, there will be no pilot light~s operat ing. If -there is 120 volt AC current applied to the power suE)ply input with no c]osure of the pressure switch, only the battery condition light will light.
If there is 120 volt AC to the power intake terminals and there is a closure of the pressure switch contacts 3 and 4 by reason of the closing of this switch due to the pressure head of undrained liquid in the pipe line, most of which is not lost when the surge valve is temporarily open, with no pump running and therefore no closure of the circuit across terminals 7-8, the amber light A will flash intermittently in addition to the battery condition light being on.
If a pump now starts~ closing circuit across terminals 7 and 8, the flashing amber light will change to a steady amber light. This happens because when a circuit is closed from 7 to contact 8, a circuit is then closed from 8 through line 83, diode D-83 and line 32, thereby shunting out the flasher. Also at this _ time DC current is then supplied to the timing circuit 21 of TDR-l which provides a time delay that precludes the possibility of surge valve actuation due to minor pressure variations during pump start-up, this circuit being from 8 through diode D-51, line I l ~f ~
52, line 5~a, timing circuit 21,to switch 26, whlch, as here shown, is through trans:Lstor 25, diode D-49, connection ~a to ground at 45. When TDR-l has timed out, the ~[~DR-l and coil 21 are energized, -the relay will operate to open eontacts 19 and close eontaets 20~ to then establish a cireuit through D-52, line 53, braneh 54, D-55 and line 56 to one side of coil CRC of control relay CR-l, the other terminal of which is connected to ground line 57, TDR-2 normally closed contacts ~ and @ through the off-delay to ground. Energizing relay CR-l operates to open its con-taets 35 to e~tinguish the amber light and apply curren-t aeross eontaets 38-39 -to apply steady current to green light G.
When steady DC flow has beerl establishecl in this way through line 56 to the eoil CRC of CR-l relay contaets 38-3~, they will remain in this condition unless or until the circ~iit is de-energized and it must then be again re-established through the operation of TDR-l, as will only occur with the next opening of the pressure switeh PS. The display of the solid green light indieates that the eireuit is armed and ready to function.

As long as the pumping station is funetioning normally the green lamp will stay lighted. With the mode switch 26 in the position shown and the coil 21 of TDR-l remaining energized, no ehange will oeeur, assuming of eourse that the battery and eharger remain in good eondition. However, should there be a power failure to the pumps or should the pressure switeh open, or both take plaee, and the eoil 21 beeomes de-energized, the protective sequenees will be initiated. The battery eondition indicator, of eourse, keeps the operator informed if there is a battery eondi-tion at fault.

- Assuming first that switeh 26 is in the position shown 30 in Fig. 3, the eireuit for eoil 21 is through ~e transistor 25 to the ground (line 48). If there is a power failure to the pumps, there will also be a power failure to the power supply unlt, since the pumps and power supply derive their current from the common source at the pumping station. This then will de-energize line 23 from the power source to the base of transistor 25 because line 23 is not in ~he battery circui-t. Transistor 25 thereupon becomes instan-tly nonconductive and there is, there-fore, no conduc-ting ground connec-tion -through the relay coil to line 48 and TDR-l instantly returns to its normal condition, opening contacts 20 and closing contacts 19. CR-l relay is not affected by the power failure, and current will then flow from line 14 on the plus pole of the bat-tery across closed contact 15, line 53, now closed TDR-l contacts 19 to -the upper end 52a of line 52, solenoid valve terminal 5, through the so:Lenoicl valveJ
to ground at terminal 6~ Also there is a circuit across te~-minals 5 and 6 throug}l red light 66 to light saicl:Light. A~ the same time branch line 60 is connec-ted through TDR-2 con-tact 11 and through this relay to ground at 61.
The same thing happens if, instead of a power failure, the pressure switch opens, TDR relay 1 loses its ground through the pressure switch to ground connection 45.
Operation of TDR-2 opens contacts 4-5 at the end of its timing cycle to de-energize the coil of CRC of control relay CR-l, returning this relay to its original condition, thereby also extinguishing the red light and closing the solenoid valve.
Both timers, as is usual, have a dial (not shown) to adjust the length of the delay and reset themselves after they operate for the next operation at the same dial setting until the dial setting is changed. Typically, the time delay relay of TDR-1 may be adjusted to range from a period of a few seconds to 300 seconds, or more, and the purpose of this delay, as previously indicated, is to avoid surge valve opening ~ith minor surges and pulsations that occur during pump start-up.
Time delay relay TDR-2 is set to provide a shorter and .

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more accurately timed operating cycle. It may be explained that with an abnormal shutdown of the pumps such as wil:L give rise to a downsurge of water pressure, the shock wave that begins with a drop in pressure in -the p~mp header travels, to the discharge ter-minal of the pipeline and then returns to t:he pumpinq statlon as a pressure surge or backflow of water and, in cl lon~ pipeline, this interval may be any time from several seconds to minutes.
Even the sound of the onrushing surge of water will be clearly audible at the pumping station before its actual arrival. It is only necessary to open the surge valve for a short period of time preceding the pressure surge of water unti:L after the force o~ the pressure surge has been dissipa-ted, and TD~ 2 ~ erefole is set co time the opening and closing of -the solenoid valve to rneet tilis schedule, which wilL differ with cli~Eerent stations, elevation of the discharge above the pumping station, and length of ~he pipe-line.
Reference has heretofore been made to mode switch 26 in the upper left corner area of Fig. 3. It is a manually operated two-position switch, and these positions are usually referred to as Mode A and Mode B; but, to avoid possible confusion with A and B of Fig. 1, they will be here referred to as MA and MB. In the diagram in Fig. 3, the switch 26 is in the MB position. If the switch 26 is moved to bypass the circuit through transistor 25 and make direct connection with wire 48b to line 48 where coil 21 will lose power only after the opening of the pressure switch to break the battery circuit to ground. Hence, in this setting, a power failure does not directly result in opening the surge valve.
If the mode switch 26 is in the MA mode and power failure - to the pumps occurs, the circuit goes into a standby armed condi-tion for about 30 seconds during which the green light 41 flashes, the only circuit at this time being ~rom the battery into the flasher through switch 15, D-55, D-83', through line 32, connector .~ - 1~ -'~

9 ~
34 and contacts 39 to green lamp 41. A 30-second armed condltion after power failure is achieved through the off-delay unit, the negative charge of which provides a continuing negative polarity to the magnet coil of CR-l. If a-t this time a pressure surge is imminent, -the TDR-2 contacts ~ and ~4) will close and assure corn-pletion of a full cycle even if the off-delay time has expired.
Should no pressure surge occur during the standby armed state, the off delay will cease to maintain a negative voltage on the negative pole (upper end in the diagrarn) of the relay coil at the end of its delay period. This removes positive current flow through the timing circuit, whereby it then cleclctivates the cir-cuit completely.
Should, however, the circui-t be armed in either ttle MA
or MB modes and a norrnal programmed shutdown ta~es place, opening the circuit across auxiliary motor starter terminals 7-~, the off-delay circui-t loses positive DC control voltage and begins its delay period of approximately 30-second to a nonconducting state for removing the negative polarity (sometimes conveniently re-ferred to as "negative DC") to the negative terminal of the relay coil of CR-l. If a downsurge occurs during this period, the cir-cuit will respond with the instant opening of the solenoid valve J, as previously described.
However, if no downsurge occurs during this period, as will hereinafter more fully appear, but with the exception that since the 120 volt AC current is not interrupted, the amber light will resume flashing, indicating a standby unarmed circuit condi-tion.
In Fig. 3 it will be observed that there is a line 65 - which comprises a conductor between the power supply and TDR-l.
When contacts 17 close, this conductor supplies current directly to provide a shunt around conductor 26 after contacts 19 and 20 are closed to take care of the increased load at this time without, - 14a -~ ~7~j8~;JP~
however, charging the circuit with the battery.
The push button test switch in Fig. 3 is shown in serles with the pressure switch and switch 46, for ease of following the overall circui~ owever, the diagonal dot-and-dash line posi-tions it near ~he lower center o the diagram. Testing of the circuit may be effected even though the pumps are not operatiny in a normal manner and the circuit is not armed.
For ease in following the test opera~ion, the reference numerals will be marked with a prime (') Eor following the test.
Positive DC is supplied from line 10 and branch line 80' to switch contacts 81' arranged to be closed b~ pressure on push button switch 82'. This will allow positive DC through d:iocle D-82 to line 56a, to line 56 to one sicle of the coiL C~C of control relay CR-I. Frolllthis point current will flow-through said coil, line 57, and off-delay to ground at 13. At the sa~e time, curren-t will flow through D-84' and D-84, causing the off-delay to conduct. This will result in the q~nu~ ofthes~,e ~ve during timing on TDR-2 through the closed contact 19 and of TDR-l the operation of the solenoid valve as previously described. At this time, manually operable valve B (Fig. 1) will be opened only slightly to avoid spilling unnecessary amounts of water through the surge valve in this test.
The Power Supply Unit (Fig. 4) As previously stated, the battery is a nickel-cadmium (NiCd) battery. Fig. 4 discloses one power supply for this battery, but the invention is not necessarily restricted to such a po~er supply. As indicated, the AC input connections connect across the primary of a step-down transformer, the secondary 100 .

I~ 30 !;.
, . .

, - 14b -o~ which is connected across the input terminals of a ~ull wa~e rectifier indicated by the square with oppositely directed diodes leading in divergent directions to ~he positive (~) and negative ~-~ output termlnals. Line 101 from the ~ side of -the rectifler ! ha~ two resi~tors indlcated as 2W and lW. TDR-l contacts short ou~ lW when the current requirements of TDR~1 and CK-l are added to the output to keep the chargin~ current to the NiCd battery unehanged, Biasing voltage for the transistor 25 ~:s provided by the positive half wave pos~ tive off-take 23, which is not 'in~the ) battery circuit.
This circuit is unique in tha~ voltage regulator VR is so connected that current flowing through external circuiting must keep a regulated voltage across the two load resl~stors lW
and 2l~. This results ~.n con&.tant current charglng for the NiCd j battery. Closing of normally open contacts 17 o T~R-1 shorts out load resistor lW, increasing the current required to rnaintaln the regulated voltage acrosA resistor lW.
This arran~ement is ~mportant in the char~ing of NiCd batteries which must normally be continuously charged at a generally uniform rate. With the arrangement here shown, the charging rate to the battery is normally regu]ated through the two resistors but, if the load increases as when TDR-1 and CR -1 have their coils continuously energized and the green lamp ls constantly burning one of the resistors lW ls shunted out, supplying more current to the load demands without lncreasing the current supply to the battery, wh~ch requires a constant ehaTging rate.
- As here diagramed, 2W and lW are indicated to be of unequal value, but these values will be selected according to the O requirements of a part~cular installation. While the circuit here shown ~s oriented to Fig. 3, it will be understood ~y those skilled in the a~t that lt will be appllcable to other circuits employing the same type of NiCd battery or constant current requirements.
I5 The Flasher ~Fig, 53 Conventi~nal 1asher circuits of varipus types may be used, such as magnetic on-off switches, thermal on-off switches but, for compactness, l1ghtness and absen~e of heating elements, ;-; . .

--.

~ 89~l but the sirnple circuit shown in ~ig. 5 has proved most satisfactory.
When posit-lve DC current is applietl to li.ne ~9' through either of the diodes D-30 or D-83' (see Fig. 3), the then discharged 0.~ capacitor A~43 ln the flash-out circuit A-44 applies bias throu~h reslstor 220 to the base o ~ransistor A-42 to thereby apply voltage through resis~o~ 6.B to the base of transistor A-92. Current then flows from the col1ec~or o~ A-92 to A-44 leading to contact 35 or 39 of C~-1 to flash either the amber or green light as the case may be. I~hen 0.2 capacity agaln becomes complete1y charged~ causing transistor A-42 to turn off, in turn causing translstor A-42 to turn off, extin~uisln~ the lamp. The capac~tor 0.~ d1scharges through the filament. of the lamp and the 220 kQ resistor to the base of A-42. This results ln drivin~ transistor A-42 hard to the cut-o~f con~itionl keepLng the lamp ext~ngu~.shed. When capacltor 0.2 completely dischar~es, the cycle repeats with ~ frequency d~term1ned by the circuit `
components. We prefer about 100 cycles per minute.
The O~f Delay ~Fi~. 6) Referring to Fi~. 6, positive current rom line 83 ~Fig. 3) is connected through diode. D-84 to the 1.megohm resistor and the base of transistor 85 to conduct current to a negaLive current path which is establ~shed through transistor 86 from ground 13 (Fi.g. 3) to contact 5 of TDR-2. When positive current is lo-~t across terminal~ 8 and 7 due to a power failure or the stopping of the last pump, the 18 mfd capaeitor B8 supplies an "on" bias to keep transistors 85 and 86 conducting for about 30 seconds after which the negative side of the circuit rom ~ of TDR-2 to 13 ceases to conduct~ ;
Battery Condition Indic tor ~F g. 7) In Fig. 3 the battery eondition indicator is connected to the positlve 1~ne 2 from the power supply and its negative side leads to contacts ~ and ~ of TDR-2 and gr~ound. Its purpose, of course, is to indicate if the battery is fully charged and capable of operating the solenoid pilot valve J ~Fig.
1) and the associated circuitryO The indicatlon is shown in red or green, preferablj on the door of the box, i$ there is a single box as previously èxplained, or at some assoclated area where lt - is always visi~le. Prefera~ly3 ~ -trichromatic li~ht emitting . . I

l 1~S89~
diode (LED) (Fig-7) supplies the indication, i.e., red or green as conditions require. The circuit is designed so that. the red indicator appears at all-times except when sorne specific clrcum-stance prevails, that is, circums-tances indicating that the bat-tery voltage during cons-tant current charging is wi-thin certain prescribed limits. These limits vary inversely wi.-~h the battery temperature. If these limits are met, the red light is extin-guished and the green LED signal light is energized.~ This green LED is of course unrelated to green light 41 in Fig. 3.
Red LED is energized through transistor 105 from con-nection Z (Fig. 3~ through conductor ln6 in which are cliodes 107 and 108, the emitter of 105 connectillg to posi~ive li.ne~ 1.06 through branch line 109. The collector of -transistor 1.05 ls cOn-nected through :line~ llO,lll whlch includes resistor l:L2 and -terminates at the red L~D. The circuit from red LED to ground or negative circuit is through conductor 113 and TDR-2 ~ .
Red LED is biased at this time through connection 114, in which the resistor 115 which connects with line 116 connecting the collector of t.ransistor 117. With this arrangement the red LED will never light when the green LED is lighted because, when transistor 117 is conducting, line 116 changes from negative to positive, reversing the polarity of the base of transistor 105.
There is a circuit comprising line 118, transistor 119, negative line 120 from the transistor to zener diode 121 and also through branch line 122 -with resistance 123 to the negative line . 109. There is thermisor circuit shunted around transistor 119 comprising line 124, resistor 125, thermistor 126, positioned physically between the cells of the battery where it responds to : - battery temperature, and line 127 in which is a 150 ohm resistor 128 ana a variable 200 ohm resistor 129. A line 130 from the . latter biases the base of transistor 119 and there is a connection 131 with resistor 132 to line 118. It will be noted that ", 8 ~) ~
transistor 119 is, in effect, reversed with respect to the other three transistors (sometimes referred to as transistors 1 to ~ in their top to bottom order in the di.agram). This reversal is to maintain a negative potential from grouncl to the emitter of 119 to meet the reverse conductivity of a zene:r diode~
When the vol-tage of the emitter of transistor 119 reaches a value such that the zener diode will conduct, resistor 132 puts sufficient negative bias on the base of transistor 117 through line 133 so that it conducts, lighting the green LED and extinguishing the red, since the collector of 117 which previously was negative now becomes positive, removing the negat:ive bias from transistor 105.
The green light indicates the battery vo:ltn~ge :is norllla:L
for the temperature of the battery at the constant prevailing charge rate. If, however, the nega-tive bias on -the base of the third transistor increases sufficiently -to bias on the base of the third transistor 136 through resistance 135 for an overriding voltage to be applied to line 133 above resistor R5, the bias on the base of the transistor 117 becomes positive and ceases to conduct whereby line 116 will again apply a negative bias to the second transistor to again light the red LED. Thus there is a flip-flop from red on undervoltage, green in the proper charging range and back to red on overvoltage, the green range being a relatively narrow band which indicates the nickel cadmium battery condition as good for any given temperature. The thermistor is in physical proximity to the battery to respond to its tempera-ture but electrically separate. It responds inversely to a temperature increase so that, as the temperature of the battery rises, the base of transistor 119 becomes increasingly positive through connection 118 and 131, increasing the negative flo-~ in line 120.
Red on the undervoltage side of green indicates a 1 ~ 7 ~

shorted cell or dischar~ed battery and, on the overvoltage, in-dicates an open cell or a blown fuse. Green spreads over a slight variation from one side or the other oE normal indicating that the battery and battery circuit are in operating condition and properly charged.
In the foregoing battery condition indicator circuit a trichromatic LED is preferred to separa~e red and green light emitting diodes, since in a border zone, when a change from one to the other is about to take place, both diodes may be operat-ing and their combined operation will produce a yellow color that will replace the red or green to at-tract attention to a changing situation.
Fig. 8 is a schematic illustration oE a modiEication wherein the pump discharge system includes a check valve that opens away from -the pump into -the pipeline and which may sometimes be open after the surge valve has closed~ To prevent closing of the surge valve before this check valve has closed, the arrange-ment disclosed in this figure provides a simple solution.
In this modification, 200 is the check valve having a gate 201 that pivots about a shaft 203, at least one end of which extends outside the casing. The view is an exploded view where the dotted line indicates the axis of this shaft and on the pro-jecting end of the shaft there is indicated an extension or cam 205 which, when the check valve is in the closed position, holds open a microswitch indicated by a casing 207, and an arm 208 that - is raised slightly to the open position when the valve gate is closed.
` When the valve gate is even partially open, the exten-sion 205 swings down, allowing the microswitch arm 208 to spring down and close the switch. Two leads 209a and 209b from the ~; switch connect across terminals ~ and ~ of TDR-2 (Fig. 3). If TDR-2 is at that time about to open the circuit to CRC of CR-l to :

~ ~$~9~
close the surge valve by opening the circuit to the solenoid valve, the microswitch then being closed provides a sh-lnt circuit across contacts ~ and ~ so that CR-l does no~ ~Iknow~ that the circuit between ~ and ~ had otherwise been opened, and thereore keeps operating to hold the solenoid valve circuit energized and keep the surge valve from closing. When the gate swings -to closed position, the microswitch opens in the manner above described and the bridging of the circuit across contacts ~ and ~ is removed and the surge valve will close.

The circuit shown in Fig. 9 is a modification of Fig.
3, but all elements common to the two circuits have like reEererlce numerals. This circui-t is especially designed for use Ln pumpLrlg stations where the surge valve and pipe discharge ~erminal are a long distance apart, so -that there is a rela-tively long time lapse between the downsurge or pressure drop at the pumping s-ta-tion when an abnormal or unprogrammed pump stoppage occurs, and the time the resultiny pressure surge arrives from the pipe ter-minal to the pumping station may be a period of many seconds to as much as two minutes or more.

In Fig. 3, TDR-2 opens the solenoid valve to open the surge valve almost instantly for a period of time selected on TDR-2, nominally from 10 seconds to 30 seconds after the pressure drop or downsurge at the pumping station and then initiates the gradual closing of the surge valve. However, with long pipelines, the opening of the surge valve should not occur until a few seconds before the arrival of the pressure wave or surge at the pumping station, so that excessive amounts of water or other liquid would not be drained from the line during that period.
In Fig. 9 there is shown a modified TDR-2 type relay with an added set of contacts which will close sometime following the initiation of the operation time of the relay and the expira-tion of the period over which it is timed to run, and the circuit .,;

~ ~7~89~
in Fig. 9 wi-th the compound series of two swltches that may be used to accomplish our purpose, that is, start the running oE the time relay in its scheduled sequence but delay opening the sole-noid valve to start the opening oE the surge valve at some defin-ite time period thereafter.
In Fig~ 9 the TDR-2 relay is here shown with contact in series with ~ through a normally closed switch as diagramed.
The switch contacts, shown at TDS (these being the initials for time delay switch) are iln series with 5, leading to the solenoid valve, as does the numeral 5 in Figs. 1 and 3. The numeral 6 is the return line from -the solenoid switch to grol~rld as in Fig. 3.
There is a diode D-90 between 5 and 6 and in serie~ between th LS
diode and 6 -there~ is a red light R corresponding to 66 in Fic~ 3.
However, there is here included th~ fLasher as in Fig. 3 through line 32A, TD~2 contacts ~ and ~ (which are normally provided on these relays but not used, and therefore not shown in Fig. 3), and line 32 so that when TDR-2 starts timing and before TDS con-tacts close to 5, the light R will flash red, indicating the delay time before the surge valve opens by closing of TDS. During this 2-0 flashing period, diode D-90 blocks the positive flashing to the solenoid valve terminal 5. When TDS contacts clse~energizing solenoid valve diode D-90 conducts positive to light the red light continuously during the time the valve is open.
In Fig. 10, a manually adjustable electrically operated timer comprises switch TDS. TDR-2 determines the overall running time lapse from its beginning to the time it reaches its "off"
condition. The timer X will be set to close the circuit between TDR-2 and the off time of TDR-2. Therefore, even -though TDR-2 is - running for the overall time from its start with closing of TDR-l contacts 19, the circuit to the solenoid valve will be closed only when timer X starts running until TDR-2 runs out.

9 ~
Conclusion As previously pointed out, ~he herein describecl cir-cuit is capable of operating in either of -two modes, to be selec-ted by the operator by manual operation of the mocle switch accord-ing to the requiremen-ts of a particular installation. The ~B mode provides surge valve actuation on each power failure or pressure switch actuation any time the circuit is arrned and for a time period of 30 seconds after the last pump is shut down.
The M~ mode provides for surge valve actuation with an opening of the pressure switch only any time the circuit is armed and for a time period up to 30 seconds aEter the last pump i5 shut down. It is desirahle where a power fai]ure may be oE a character where no signifcant downsurge will Eollow ~or exarnplc, if there were a pc~wer failure to a sincJle small pump in a lc~rge p~m~ing sta-tion, the pressure switch might not respond because the eEfect woulclbe too ; small to produce a surge, even if at the time of the power failure,-the demand at the output would require no other pumps to be operating and this remaining small pump would be the last pump to operate.
Briefly summarizing, the invention provides a compact solid state circuit for use in a pumping station as described, wherein an operator at a glance can be aware of the condition of the surge control system and is given advance warning of condi-tions which may be expected to produce a pressure surge of poten-tially destructive character and open the surge valve sufficiently in advance of the surge, but not so prematurely as to spill exces-sive quantities of water before the actual surge takes place. It provides for re-arming itself after the surge has passed and nor-mal conditions are restored, i.e., AC power, normal pressure, pump started, and the invention informs the operator of when the cir-cuit is in condition to safely reactivate the pumps but preventsoperation of the surge valve in a preset time period. Two manually adjustable time delay relays and a single circuit relay are under - 21a -.~

I ~ 7 5 8 9 ~
the control of one or -~he other time delay relays. Mode selec-tion provides for -the adaptation of a - 21b -~ ~58(J~
single unit or box to different pumping station requirement~ most llkely ~o be encountered. Overpressure conditions are taken care o~ in the usual manner without intervention or operatlon of the present c rcu ~ or bo-~ -,1

Claims (3)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A battery condition indicator for use in a circuit comprising a DC power supply connected across the terminals of a nickel cadmium battery, comprising: (a) a branch connection to the positive side of the power supply; (b) a second branch leading to the negative side; (c) four transistor circuits arranged in parallel, the first three of which have their emitters connected with said positive branch, the fourth being reversed with its emitter connected with the negative branch; (d) the second transistor having its plate connected with the collector-to-green LED circuit of the first transistor;
(e) the fourth transistor with a negative emitter circuit between the negative branch and the emitter; (f) a zener diode having a connection from the negative emitter circuit of the fourth diode through said zener diode with the base of the first transistor with a resistor between the zener diode and the base of said first transistor; (g) a shunt circuit around said re-sistor wherein the base of the third transistor is connected through a resistor to the connection leading from the zener diode to the base of the first transistor at a point between the zener diode and the resistor in said connection, the collec-tor circuit of the third resistor being also connected to the connection between the zener diode and the base of the first transistor but joining said connection between the said resistor in said connection, (h) the said circuits being so arranged that a normal charging current path will put a negative bias on the base of the first transistor to light the green LED, thereby extinguishing the red, but lighting the red if the green is extinguished, and under normal voltage lighting the red by an absence of adequate negative voltage in the base of the first transistor, and the lighting of the green by the application of adequate negative voltage through the zener diode circuit to bias the first transistor, the green LED being extinguished when the charging voltage is above normal by the positive voltage from the collector of the third transistor offsetting the negative flow from the zener diode, but by reason of the resistor in the connection between the zener diode and the base of the first transmitter enabling the zener diode to continue to supply a negative bias to the base of the third diode.

2. The battery condition indicator defined in claim 1, in which a thermistor inversely responsive to temperature is shunted across the emitter and base circuits of the fourth transistor to vary the negative voltage to which the zener diode responds.

3. The battery condition indicator circuit defined in claim 1, wherein the red and green LEDs are combined in trichromatic arrangement to produce a yellow light in transition areas where both may be in a borderline state of operation between red only or green only.