US2370103A - Indicating means for pumps - Google Patents

Description

Fb. 20, 1945. N. F. ZAPF INDICATING MEANS FOR PUMPS Filed July 15, 194s rm @y j@ rm n?? ya Patented Feb. 20, 1945 INDICATING MEANS FOR PUMPS Norman .F. Zapf, Milton, Mass., assigner to Manning, Maxwell & Moore, Incorporated, New York, N. Y., a corporation of New Jersey Application July 15, 1943, Serial No. 494,797

. (Cl, 10S-1) 12 Claims.

This invention ,pertains to indicating means and relates more particularly to means for indicating whether or not a fluid driven pump is effectively operating. While of more general utility the device is herein illustrated by way of example 'in its application to the feed water system of a locomotive boiler.

Heretofore there has been no effective apparatus available for informing the locomotive engineer or fireman whether, at any given instant, the boiler feed apparatus (pump or injector) is actually delivering water to the boiler, the usual water level gauge being wholly unreliable for this purpose. However, it is desirable and in fact necessary that the operator be informed at once after he has performed the proper manipulations for starting the pump, whether, in response thereto, the pump is actually delivering water in suflicient volume.

The principal object of the present'l invention is to provide indicating apparatus operative 'to indicate `whether or not water at effective pressure is being delivered by such a pump. A further object is `to provide indicating means operative to show whether vsteam is being supplied to the pump. A further object `is to provide indicating means of simple, reliable, and accurate type useful, wherever a fluid delivery pump is driven by pressure fluid, to indicate to the operator whether or not the pump is in effective operation. Other and further objects andradvantages of the invention will be pointed out hereinafter in the following more detailed description and rby Areference to the accompanying ydrawing wherein Fig. 1 is a fragmentary, diagrammatic view illustrating portions of a boiler .feed system having the indicating means of the present invention embodied therein;

Fig. 2 is a side elevation of a casing .forming a part of the indicating means of the present invention; rand Fig. 3 is a `section substantially on the line 3--3 of Fig. 2.

Referring to the drawing, the numeral I designates a steam supply Apipe leading from a boiler (not shown) to the boiler feed pump 2. This feed pump vmay be of rany .acceptable `type and is not here shown in detail. From this pump a water delivery pipe 3 extends to the boiler. At a point between the pump `and boiler this pipe `is provided with an orice 4 so designed as to cause a substantial difference in pressure at 4its lopposite sides when water is flowing through the pipe.

The controlling mechanism included in the The lower part of the side wall of casing memn ber 6 is providedwith an internally screw-threaded opening I'I which receives one end of a pipe I2 leading lfrom the water delivery pipe 3 at a point between the pump and Athe orice 4. The hollow casing 5 deiines a large `chamber I3 in which is arranged a "pressure-responsive movable diaphragm device, here shown as a metallic bellows I4, one end of which is `iixed leak-tight to the cover 'I 4so 'that the interior of this bellows is in communication with the `pipe I0. The opposite end-,of the bellows is closed by `a rigid head I4a from the center of which projects a bracket I5 carrying a pivot pin I6 which engages one end of a lever Il. This lever is fulcrumed at its opposite end lon a pin I8 carried by a bracket I9 fixed to the wall of the casing member B; i

The casing member 6 is provided with an external boss 21D having a screw-threaded socket 2| which receives one end of a vpipe 22 leading from the steam supply pipe I. The threaded bore 2| in the boss 2U communicates wit-h a chamber 23 within the thickness of the Wall vof the casing member 5, the lower part of this chamber 23 having mounted therein a removable valve seat bushing 24 having an axial passage Whose lower end is defined by an annular valve seat with whichcooperates a conical valve member 25, here shown as integral with the upper end of a vertically slidable valve stem 21 surrounded by packing 28 held under lcompression by a gland 29. The lower end of the valve stem 2l is pivotally connected to the lever Il so that as the lever moves up and `clown the vvalve '.26 is moved 4.toward lor from its seat. The axial passage through the valve bushing 24 communicates (when the valve is unseated) with a chamber 29 below the bushing, said chamber communicating with a, screw-threaded bore 3B, in the boss 20, which receives one end of a pipe 3| leading to the locomotive cab lor other convenient point of observation where it terminates in a telltale pipe 32 (preferably downwardly directed) open to the atmosphere.

It will be noted that as thus constructed, the

apparatus provides for exposure of the interior of the bellows I4 to the delivery pressure of the water in the pipe 3 at a point between the orifice 4 and the boiler, while at the same time the outer surface of the head member I Ila of the bellows is exposed to the delivery pressure of the water in the pipe 3 at a point between the pump and the orice, the latter pressure being somewhat higher, when the water is iiowing in full volume, than the pressure between the orifice and the boiler.

When the feed pump is not in operation the lever II tends to swing downwardly by gravity, assisted by the resilient tendency of the bellows I4 to expand, but if the valve 26 is not thereby unseated the next subsequent admission of steam into chamber 23 will positively unseat the valve. 'When the feed pump is to be started the operator opens a valve (not shown) designed to admit.

steam from the boiler to the steam supply pipe I. Assuming that the valve 26 isunseated at this time either by gravity or the steam pressure above it, steam from the steam supply pipe I immediately flows through the pipe 22 into the chamber 23, thence through the bore in valve bushing 24, and past the open valve into the chamber 29, and thence through the pipe 3l to the telltale 32 from which it escapes as a visible plum'e into the atmosphere, thus notifying the operator that boiler steam has been admitted to the supply pipe E. Until the pump starts and becomes effective to deliver water in volume through the pipe 3 this ow of steam outwardly through the telltale continues. However, when the pump actually builds up effective delivery flow in the pipe 3 there results, by reason of the orifice 4, a differential pressure in the pipes I and I2, the parts being so designed and arranged that when such differential pressure has been established, the bellows head Illa will be forced upwardly by the excess pressure in the chamber I3, thus seating the valve 26 and cutting off communication between the pipes 22 and 3|. The escape of steam through the telltale thus immediately ceases, thus indicating to the operator that the pump is in effective operation. If the pump should stop or if anything should stop the flow of water through the pipe 3, the valve 26 is again unseated and the escape of steam through the telltale noties the operator that something has gone wrong with the feed apparatus.

When, after a suitable period of operation, the operator shuts on steam from the pipe I, the pressure in the pipe 3 at opposite sides of the orice 4 tends to become substantially equal, since there is no longer an effective volume of huid flowing through this pipe, and thus the lever Il is permitted to resume its normal position in which the valve 2S is unseated in readiness for a repetition of the cycle of operations.

While the device as above described is particularly useful in connection with the feed water system of a locomotive boiler, it is obvious that it might equally well be applied to the feed water system of any type of steam boiler. Likewise the apparatus may be applied to any system wherein a pump driven by a pressure uid, is designed to deliver anothel` fluid through a delivery pipe against a back pressure. For example, the pump might be a water pump for supplying a. reservoir and the pressure uid for operating the pump might be compressed air, but in the latter event it is obvious that the telltale device hereinabove referred to would be replaced by a gauge or other pressure indicator responsive to compressed air and which would show visually or otherwise whenever air was being admitted to the gauge or its equivalent through the pipe 3l from the source of supply.

While one desirable embodiment of the invention has been illustrated by way of example, it is to be understood that the invention is not necessarily limited to this precise embodiment, but is to be regarded as broadly inclusive of any equivalent constructions falling within the scope of the appended claims.

I claim:

1. In combination with a fluid delivering pump driven by pressure fluid delivered to it by a supply conduit, indicating means comprising a movable part whose position is determined by differential fluid pressures at spaced points in the pump delivery conduit, and a valve actuated by said movable part and operative to permit or to cut off the flow of pressure fluid from said pump supply conduit to a point of observation.

2. In combination with a steam driven water pump to which steam is furnished by a supply pipe, indicating means comprising a movable part whose position is determined by the pressure of water in the pump delivery pipe, and a valve actuated by said movable part operative to permit or to cut off the delivery of steam from said supply pipe -to a point of observation.

3. In combination with a steam driven pump to which steam is supplied by a conduit, indicating means comprising a movable parts whose position is determined by differential fluid pressures at spaced points in the pump delivery conduit, and a valve actuated by said movable part operative to permit or to cut off the delivery of steam from said supply conduit to a point of observation.

4. In combination with a steam driven water pump to which steam is furnished by a supply pipe, indicating means comprising an indicator pipe open to the atmosphere at a point of observation, a movable part whose position is determined by differential water pressures at spaced points in the pump delivery conduit, and a valve actuated by said movable part operative to permit or to cut off the delivery of steam from said supply pipe to the atmosphere through the indicator pipe.

5. In combination with a steam driven water pump to which steam is furnished by a supply pipe, indicator means comprising a telltale pipe open to the atmosphere at a point of observation, a movable diaphragm exposed at opposite sides to the pressures subsisting at spaced points respectively in the pump delivery pipe, and a valve actuated by said diaphragm and operative to determine the delivery of steam from said supply pipe into the atmosphere through the telltale pipe.

6. In combination with a steam driven pump having a steam supply pipe, indicating means including a telltale pipe open to the atmosphere at the point of observation, an orice in the pump delivery pipe, a movable diaphragm exposed at opposite sides respectively to the delivery pipe pressures at opposite sides of the diaphragm, a valve controlling a passage leading from the steam supply pipe to the telltale pipe, and connections for transmitting motion from the diaphragm to the valve, the diaphragm being operative so to position the valve as to admit steam to the telltale pipe from the steam supply pipe whenever the pressure differential at opposite sides of the diaphragm falls below a predetermined value.

7. In combination with a steam driven pump having a steam supply pipe, indicating means including a telltale pipe open to the atmosphere at the point of observation, an orice in the pump delivery pipe, a metallic bellows having a movable head, the interior of the bellows being exposed to the uid pressure subssting at the delivery side of the orifice in the pump ,delivery pipe and the exterior side oi' the bellows head being exposed to the fluid pressure subsisting at the other side of the orice, a valve which controls a passage leading from the steam supply pipe to the telltale pipe, and connections for transmitting motion from the bellows head to the valve, the parts being so constructed and arranged that whenever steam is supplied to the pump it is admitted to the telltale pipe, but only until a predetermined pressure differential has been built up between opposite sides of the orifice in the pump delivery pipe.

8. Indicating means for use in a system wherein fluid is delivered by a pump against a back pressure through a conduit and wherein the pump is driven by pressure fluid supplied to it through a pipe from a pressure source, said indicating means including an orice in said conduit operative to establish a differential pressure at its opposite sides, when uid is flowing in the conduit, a casing having therein a cavity which always communicates with the conduit at one side of the orice, the casing having therein an expansible chamber provided with a movable wall which is externally exposed to the pressure in said chamber and whose interior is exposed to the pressure which subsists in the conduit at the opposite side of the orifice, means providing a passage leading from the pressure fluid supply pipe to a point of observation, a valve controlling said passage, and connections for transmitting motion from the movable wall of said expansible chamber to the valve, the parts being 4so constructed and arranged that the valve is closed whenever a predetermined pressure dilerential is established at opposite sides of the oriflce.

9. In combination with a fluid driven pump having a delivery pipe and a pipe for supplying driving fluid for operating the pump, indicating means normally operative to reveal the presence of pump driving uid in the supply pipe, and means responsive to the presence of iiuid under pressure in the pump delivery pipe to terminate the operation of the indicating means.

10. A fluid actuated liquid pump having a delivery pipe, a pipe for supplying driving'fluid to the pump, indicating means normally operative to reveal the presence of iiuid in said supply pipe, and means including a movable part Whose position is determined by differential pressure at spaced points in the pump delivery pipe to prevent operation of the indicating means while liquid is being delivered under pressure by the pump. ,v

11. In combination with a steam driven boiler feed pump, a pipe for supplying steam to the pump for driving the latter, a conduit leading from the steam supply pipe to indicating means constructed and arranged to show the presence of steam in said conduit, and means operative in response to delivery of Water under pressure by the pump to stop the admission of steam to said conduit.

12. In combination with a steam driven boiler feed pump, a pipe for supplying steam to the pump for driving the latter, a conduit leading from the steam supply pipe and opening to the atmosphere at a point of observation, and means operative in response to the pressure of water delivered by the pump to stop the flow of steam through said conduit.

NORMAN F. ZAPF.

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