US449243A - Alexander bryant and william j - Google Patents

Description

'(No Model.)

A. BRYANT & W. J. CROW. SAFETY VALVE FOR EXPANSION PIPES.

No. 449,243. 4 Patented Mar. 31, 1891.

UNITED STATES PATENT OFFICE.

ALEXANDER BRYANT AND \VILLIAM J OROlV, OF NE\V YORK, N. Y.

SAFETY-VALVE FOR EX PANSION-PIPES.

SPECIFICATION forming part of Letters Patent No. 449,243, dated March 31, 1891.. Application filed October 9, 1890. Serial No. 367,509. (No model.)

To all whom it may concern:

Be it known that we, A EXANDER BRYANT and WILLIAM J. CROW, both of the city, county, and State of New York, have invented a new and useful Improvement in Safety- Valves forExpansion-Pipes; andwedohereby declare that the followingis a full and exact description thereof, reference being had to the accompanying drawings, and to the letters of reference marked thereon, making a part of this specification.

Our invention relates to a device for preventing a flow and waste of water through the boiler in the water-supply system of a dwelling-house or other building by reason of an undue pressure in the cold-water feed-pipe.

In the approved systems of hot-water sup ply for a city house it is customary to carry an open pipe, known asan expansion-pipe, from the top of the boiler to a point above the supply-tank or highest point of delivery.

' This expansion-pipe operates as a safety detherein.

vice to guard the boiler against the possibility of undue pressure by reason of a generation of steam therein, provision being made for the water which may overflow from the pipe usually by carrying the end of the pipe above the supply-tank. so that it may discharge Where, however, as is usually the case, the boiler is connected directly with the street-main, it often happens that unless pains be taken to shut off this connection at night the increased pressure in the main which then occurs by reason of the lessened demand for water operates to produce a constant flow through the boiler and out of the upper end of the expansion-pipe, so that in a short time the hot water in the boiler will all be discharged therefrom and replaced by the cold water delivered from the main.

The object of our invention is to prevent by an automatic device this discharge or flow of water through the boiler under this increase of pressure; and it consistsin the combination, with the boiler, its supply-pipe, and expansion-pipe, of a vertically-moving valve fitted to move outwardly against a suitable seat in the end of the expansion-pipe and thereby efiectually close the pipe, and which will drop back automatically from its seat by reason of its weight alone, so as to open the pipe. This cut-off valve is made to close an tomatically by means of an inverted. cup or hollow cylinder upon which the valve is carried, and which is fitted to play so loosely within the pipe as to permit an escape of air around it when the valve has dropped from its seat, but which will be carried up as a float by a column of water rising therein, and thereby lift the valve against its seat, so as to close the pipe and prevent an escape of the water therefrom, and is constructed with a central vent-passage through it, which is closed by an auxiliary valve automatically closed by a spring and opened when an excess of pressure occurs in the hollow cylinder by means of a suitable float fitted in said cylinder, all as hereinafter described and claimed.

In the accompanying drawings, Figure 1 represents in elevation a hot-water boiler with its supply and expansion pipes, the latter fitted with our automatic cut-0d valve. Fig. 2 is an elevation upon an enlarged scale of the cut-off valve with the top deflecting-hood removed; and Fig. 3, a central longitudinal section thereof in line .0: as of Fig. 2 with the hood in place. I

A represents the hot-water boiler in the water-supply system of a building, connected in the usual manner by a circulating-pipe B with the watcr-back in arange or other heating apparatus.

O is the eold-watensupply pipe connected directly with the main.

D is the expansion-pipe extending as is usual from the top of the boiler A to a point above the highest level of the delivery-pipes, and preferably over the tank E.

F represents our automatic cut-off valve fitted upon the upper end of said expansionpipe. This valve is constructed of a cylindrical shell or casing F, contracted at its outer upper end, as shown in Fig. 3, so as to form an annular seat or offset g about the opening in said end, and which is exteriorly threaded at its opposite lower end to receive a coupling-ring ll, serving to couple it in the customary manner with a ferrule K, by which to connect it with the end of the expansionpipe D. The ferrule K is of smaller diameter than the casing F, so as to form with the latter when the two are united an internal pipe.

ofiset t. A washer L, interposed between the casing and ferrule, as shown in Fig. 3, projects inwardly to rest upon this offset.

Within the casing F is fitted a hollow cylinder N of thin metal, closed at its upperend and left free to play loosely within the casing, so as to drop and rest by its weight alone upon the washer L on the end of the ferrule. The diameter of this cylinder N is such as to permit a passage of air about its periphery through the casing, its lower end being notched, as at M, to establish communication between the expansion-pipe D and said air passage. An open-ended tubular pin S is secured upon the outer upper end of the hollow cylinder N, and a rubber valve P is fitted upon said pin and confined by a nut T. This.

valve P is of sufficient diameter to seat itself when uplifted for the purpose against the contracted end 9 of the casing F, so as to close thereby the opening in the end of the An auxiliary valve a is fitted to seatitself upon the upper end of this central tube S, said valve being connected by acentral spindle 12, extending down through the tube S, with the closed end of an inverted cup N playing freely within the cylinder N. The valve a is kept automatically closed by means of a spring W, interposed between the cup N and the top of the cylinder N, the strength of said spring being so adjusted as that it will not permit the valve a to open under the pressure which will operate to close the valve P, but will yield if, after said valve P is closed, the pressure becomes so great as to endanger the boiler or pipes, and, yielding, will thereby allow the valve a to open and relieve the pressure.

A hood U is fitted over the top of the valvecasing F to deflect any water which may be forced out through the valve F and cause it to drop back immediately into the tank E, over which the valve is located.

In the operation of our invention,when the water-pressure in the boiler A is normal, so that the level of the water in the expansionpipe D is below the outer end of the pipe,the cylinder N, carrying the valve P in the valvecasiug F, secured upon the outer end of the pipe, will drop of its own weight and rest with its lower notched edge upon the washer L, and thereby leave the aperture in the outer end of the pipe free. With the valve P in this position free vent is afforded to the air in the upper end of the expansion-pipe D through the notches r r in the lower edge of the cylinder N and the narrow space left between said cylinder and the inner periphery of its casing F, so as to permit the waterlevel in the pipe D to rise and fall freely, as in an open pipe. When, however, the press ure of the water-supply to the boiler has so far increased as to cause the water to rise above the level of the valve, the water rising under the cylinder N will by reason of the air which will be caught and confined within said cylinder cause it to rise, and in rising will cause the valve P to close the open end of the casing F, and thus efiectually prevent an outflow of water through it, so that a circulation of the water-supply into and through the boiler and out through the expansionpipe cannot take place and the discharge by this means of the hot water in the boiler through said expansion-pipe be entirely prevented.

An undue pressure in the boiler'and expansion-pipe after the cut-off valve P is closed from a generatiomof steam in the boiler or other cause is prevented by the operation of the central auxiliary or safety valve a.

We claim as our invention'- 1. The combination, in the water-supply system for a building, with the hotwater boiler, its cold-water-supply pipe and its expansion-pipe, a valve-casing fitted upon the upper end of the expansion-pipe and having a contracted valve-opening at the top, and a valve adapted to close said opening carried upon the upper closed end of a hollow cylinder left open at its lower end and fitted to play loosely within said casing, of a central vent-openin g through the valve, a spring-actuated valve closing said vent, and an auxiliary float placed within the hollow cylinder and attached to the vent-valve to open it against the stress of its spring, substantially in the manner and for the purpose herein set forth.

2. The combination, with the expansionpipe D, the valve-casin g F, fitted thereto,'having an opening in its outer end, and the hollow cylinder N, playing loosely in said casing, of the central tube S, secured to project from the upper closed end of the cylinder N, the rubber valve P, encircling said tube and adapted to close the outer end of the valve-casing when lifted thereto, a spindle b, fitted loosely in the tube, a valve a, fitted upon the outer end of the spindle to drop upon and close the end of the tube, an inverted cup or float N, playing loosely with the cylinder N and secured to the spindle, and an interposed spring WV, all substantially in the manner and for the purpose herein set forth.

In testimony whereof we have signed our names to this specification in the presence of two subscribing witnesses.

ALEXANDER BRYANT; WILLIAM J. CROW.

Witnesses:

A. N. J ESBERA, E. M. WATsoN.

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