US513234A - Valve - Google Patents

Description

L. J. HIRT.

(No Model.)

VALVE.

No. 513,234. Patented'Jan. 23, 1894.

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UNITED STATES PATENT QEETcE@ LGUIS J. HIRT, lOF BOSTON, MASSACHUSETTS.

VALVE.V

SPECIFICATION forming part of Letters Patent No. 513,234, dated January 23, 1894.

Application filed August 26, 1893- Serial No.484u087- (No model.)

To all whom it may concern:

Be it known that l, LOUIS J. HIRT, of Boston, county of Suffolk, State of Massachusetts, have invented an Improvement in Valves, of which the following description, in connection with the accompanying drawings, is a specification, like letters on the drawings representing like parts.

i, My inventionrelates to a valve intended to be used to control communication between a water or liquid supply pipe and distributing pipes, and constructed to normally exclude the water from the distributing pipes, and to be opened automatically when an outlet is provided from said distributing pipes. A valve of this kind may be used for example in connection with supply and distributing pipes arranged for the extinguishing of fires, in which the Water is to be normally excluded from the distributing pipes to prevent danger of freezing or for any other reason. p

The invention is embodied in a differential valve having its differential area exposed to the pressure of the water in the supply main which acts on the unbalanced area with a tendency to open the valve. A full larger area of the valve is exposed to the pressure maintained in the delivery pipes, and a pressure of comparatively small amount per unit of surface in the delivery pipe is thus sufiicient to retain the valve closed, but when the said pressure is removed the unbalanced pressure of the liquid in the supply pipe will open the valve and Will continue to flow through the 'said valve as long as an outlet is provided from the delivery pipe. Then the valve is open the fluid has accessto the smaller area in the valve so as to act upon the same in the direction opposite to that of the normal pressure of the fluid on the said smaller area of the valve, and consequently when the valve is unseated theliquid pressure upon it is substantially balanced and the valve is held open by the slight excess in pressure in the supply pipe over that in the delivery pipe due to the current or movement of the liquid from the former to the latter.

Figure l is a side elevation of a valve embodying this invention, and Fig. 2 a longitudinal vertical section thereof.

The operating parts are contained in a shell or casing a having an inlet opening a2 adapted to be connected with the supply main*f b,

'and an outlet opening a3 to be connected with the delivery pipe c a portion only of which is shown in Fig. 1,it being understood that said delivery pipe extends to such points as may be desired, and is normally closed and provided with any desired number of outlets as extinguishing fires and the outlet c2 may be provided with distributers or nozzles for the direct distribution of the water or may be adapted to have a hose connected therewith, the said outlets being provided with a shut off or stop cock of some kind, either automatic or not in its action. When the outlets from the delivery pipes are closed a moderate pressure can be easily maintained in the said delivery pipes and such duid pressure is employed to retain the main valve in the shell a normally closed, the said valve being so constructed that when said moderate pressure is reduced or removed by opening one of the outlets c2 the said main valve will be opened by the pressure of the liquid in the supply main h and will then remain as long as an outlet from the pipe c is provided.

The main valve proper D, see Fig. 2, is a differential valve having two portions d, d2, ofdifferent area connected by a stem d3. The lower smaller portion d2 of the valve seats over a pocket or chamber d4 iu the shell o., which chamber is normally in communication with the surrounding atmosphere so that the lower surface of vthe fdisk cl2 is exposed only to atmospheric pressure while its upper surface is exposed tothe pressure of the liquid in the supply pipe B which pressure thus tends to hold the valve seated. Communication between the chamber 0.4 and the outside atmosphere is as shown in this instance effected through a pipe e opening into a valve chamber e2 provided with an outlet e3 and containing a valve e4 shown as a ball adapted to seat either on the mouth of the pipe e or that of the pipe' e3 entering the valve chamber e2. is admitted into the chamber 0.4 and tends to escape therefrom through the pipe e its pressure will lift the valve e4 and seat it on the mouth of the delivery pipe e3 and thus prevent the escape of water under pressure from IOO Thus when the liquid under pressure r the chambermat. The pipe e may also beprovided with a drain cock e5 which may be opened to drain the chamber a4 when the main valve D is seated thus emptying the chamber .a4 and establishing atmospheric pressure therein which is then maintained after the drain cock e5 is closed until such time as the main valve D may be opened. The upper disk CZ of the main valve is of larger area than the lower disk d2 and Aworks on a seat around an opening a5 that establishes communication between the supply pipe Z2 and delivery pipe c except when such communication is cut off by the main valve D, which when closed has the upper surface of the lower disk d2 and tho under surface of the upper disk d acted upon in opposite directions by the pressure of the liquid in the supply pipe b which thus has an effective upward or lifting force equal to the product of the pressure per unit of area into the difference of the exposed area of said upper and under surfaces. Assuming for example, that the areas of the said disks` are in about the ratio of seven to eight, or for example, fourteen and sixteen square inches respectively a and the pressure of the water is forty pounds to the inch then there would be an unbalanced lifting force of" forty pounds to the inch on the two inches excess of area of the upper surface over the under, or in other words a total lifting force of eighty pounds tending to open the valve. This lifting force is normally overbalanced and the valve retained seated by pressure in the delivery pipe c which acts upon the upper surface of the upper disk d of the main valve on the entire area thereof and is substantially unbalanced as there is no upward pressure on the lower disk cl2 above the atmospheric pressure. Thus assuming that the area of the upper disk d is sixteen inches, a pressure of ive pounds per inch above the atmospheric pressure on this surface would just balance the eective lifting pressure on the water, assuming that the upperand under exposed areas of the disk are equal; but inasmuch as owing to the form of the valve seat there is really a larger area exposed to downward pressure than to upward pressure the pressureof five pounds to the inch in the delivery pipe c will practically overbalance the pressure of forty pounds to the inch in the supply pipe b and the valve D will thus remain seated until such pressure in the delivery pipe is reduced. Thus the main valve will remain closed excluding the water from the delivery pipe c as long as the moderate pressure (in this supposed case, tive pounds per inch) is maintained in said delivery pipe, and it is easy to maintain a llow pneumatic pressure of this kind, asY the tendency to leakage is not great and the pressure can easily loe restored by forcing a little air into the delivery pipe in case the pressure is observed to fall away slightly'.

In practice a pressure of a pound or two in excess of what is just enough to retain the main valve seated lshould be maintained. When, however, this pressure is removed as by opening the discharge passage as c2 from the delivery pipe c the lifting force of the Water in the supply pipe acting on the valve D is no longer balanced and the latter is opened there being in the supposed case, a lifting force of eighty pounds which is ample to insure the operation of the valve. As

` soon as the valve is thus opened water passes through the opening a5 from the supply pipe b into the delivery pipe c and thus tends to produce a back pressure on the upper surface of the disk d, but the same operation that admits water into the delivery pipe also admits water past the lower disk LZ2 into the chamber a4, so that `the entire under surface of the valve is now exposed to the pressure in the supply pipe which is sufiicient to maintain the valve open with a continued flow of water into the delivery pipe.

The stem d8 connecting the upper and lower disks of the main valve is itself made tubular or provided with a passage, the upper end of which is provided with an upwardly open ing check valve d4 which when the main valve is open is exposed to the full lpressure` of water in the supply pipe which thus tends to lift the auxiliary check valve d4 permitting a moderate iow over theA seat of the lower disk d2 of the valve and through the chamber 0,4 and thence up through the stem dinto the delivery pipe c, such flow tending to wash the lower valve seat and chamber and to thereby keep them clean so that the valve will seat tightly when it is again closed.

As the valve is kept open only by the excess of pressure in the supply pipe over that in the delivery pipe due to the flow from the former to the latter, it is desirable that the valve should be as light asis practicable, and in practice excellent results are obtained by making the said valve of aluminum.

The shell a, in which the valve operates is provided with a rem'ovable cover or bonnet a over the valve so that access may be obtained to the valve when required, and the said cover is provided with one or more depending lugs or projections a 'which operate as a stop to limit the opening movement of the valve.

In order to close the main valve it is neces` sary only to stop the delivery from the outlet of the delivery pipe, when the fiow of the liquid through the pipes will be stopped and the pressure .on all parts of the val ve D equalized so that the said valve will sink by gravity to its seat, the auxiliary check valve d4 preventing the trapping of the liquid in the chamber a4 which might otherwise interfere with the tight seating of the valve. As soon as the main valve comes to its seat the auxiliary valve d4 will also be seated thus shutting off the chamber at from communication both wlth the supply and delivery pipes, so that by draining the said chamber through the drain cocke5 or otherwise the pressure will be wholly removed from the under surface of the smaller disk of the valve which will then be retained seated by the pressure in the delivery pipe acting on the entire area of the up,- per disk, and thus overbalancin g the pressure in the supply pipe acting effectively on the dierence in area between the upper and under disks. The water-may then be drawn off from the delivery pipes by means of a drain passage f or otherwise, care being taken to maintain a moderate pressure in the delivery pipe as the water is withdrawn therefrom by forcing in air at some suitable point. The water Vis preferably left standing in the delivery pipe and upper portion of the valve shell a as shown so as to submerge and seal the main and auxiliary valves which will thus be tighter than if exposed only to air on the upper surface. Vith a main valve of this construction a slight leakage of liquid through the main valve will not cause it to open as such liquid as may pass through the opening a5 into the discharge pipe Will tend to increase the back pressure and thus retain the valve more tightly seated while a moderate leakage in the chamber a4 will escape through outlet pipe e, e3, without closing the valve c4 against the mouth of the discharge portion e3 of the outlet pipe and consequently without producing back pressure in the chamber a4 suficient to lift the main valve.

The appearance of a small amount of water issuing from the pipe e3 will afford indication that the valve is leaking, so that proper action may be taken to prevent such leakage if objectionable.

The areas of the different portions of the main valve will of course be properly proportioned with relation to the pressures to be maintained, it being necessary only to give the upper disk a sufficient excess of area over the under disk to enable the pressure normally maintained 'in the supply pipe and acting effectively on said excess of area to be sufficient to insure the lifting of the valve, while the pressure maintained in the delivery pipe and acting upon the entire upper area of the valve should be sufficient to overbalance the said lifting pressure.

The terms upper and under have been used with reference to the apparatus in the position illustrated which is the position in which it will-be ordinarily used, but it is obvious that except so far as the action of gravity on the valve is concerned, the parts mayv be used in any position and the force of a spring may be appliedinstead of the force of gravity as an equivalent therefor to produce proper operation of the valve.

I claim- 1. The combination of the valve shell hav-y ing an inlet opening adapted to be connected with a supply pipe for fluid under pressure and an outlet opening adapted to be connected with the delivery pipe in which a lower pressure is normally maintained, with a differential valve having surfaces of different areas exposed to the pressure in the supply pipe which acts on the larger area in the direction to unseat the valve, and on the smaller area in the opposite direction thereby -partially counterbalancing the unseating pressure, the said valve normally having its larger area exposed to the pressure in the delivery pipe acting in the direction to retain the valve seated, and its smaller area substantially without pressure in the direction to unseat the valve, substantially as described.

2. The combination of the valve shell having an inlet opening adapted to be connected with a supply pipe and an outlet opening adapted to be connected with a delivery pipe and a chamber normally communicating with the atmosphere, with a differential valve having a smaller portion controlling communication between the inlet opening and said chamber, and a larger portion controlling communication between said inlet and outlet openings, a passage through said valve and a secondary valve in said passage controlling communication between the said chamber of the valve shell and its outlet opening, substantially as and for the purpose described.

3. The combination of the valve shell having an inlet opening adapted to be connected with a supply pipe, and an outlet opening adapted to be connected with a delivery pipe and a chamber and outlet therefrom to the atmosphere, provided with a valve as e4 adapted to close said outlet when said chamber is filled with fluid under pressure, with a differential valve having a smaller portion controlling communication between the inlet opening and said chamber, and a larger portion controlling communication between said inlet and outlet openings, substantially as and for the purpose described.

4. The combination of the valve shell having an inlet opening adapted to be connected with a supply pipe and an outlet opening adapted to be connected with a delivery pipe and a chamber normally communicating with Athe atmosphere, with a differential valve having a smaller portion controlling communication between the inlet opening and said chamber, and a larger portion controlling communication between said inlet and outlet openings, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

- LOUIS J. HIRT.

Witnesses:

JOHN H. MoRIsoN, JAs. J. MALONEY. x

IOO

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