US1262355A - Safety-valve. - Google Patents

Description

W. F. KIESEL, In.

SAFETY VALVE.

APPLICATION FILED JAN. 12. I918.

Patented Apr. 9,1918.

2 SHEETS-SHEET I- MUCHA ,v

W. F. KIESEL, JR.

SAFETY VALVE.

APPLICATION FILED JAN. 12. me.

1 62,355, Patented Apr. 9, 1918.

2 SHEETS-SHEET 2.

WILLIAM F. KIESEL, JR, OF ALTOONA, PENNSYLVANIA.

SAFETY-,VALVE.

Specification of Letters Patent.

Patented Apr. e, 1918.

Application filed January 12, 1918. Serial No. 211,574.

To all whom it may concern: 7

Be it known that I, WVILLIAM F. KIEsEL, Jr, a citizen of the United States, and residing at Altoona, Blair county, State of Pennsylvania, have invented certain new and useful Improvements in Safety Valves, of which the following is a specification.

This invention relates to safety valves for steam boilers, particularly to that type of safety valve in which a pilot valve and balancing piston are employed to avoid the use of springs or weights which are not suitable for use in connection with the modern high pressure boilers, such as locomotive boilers.

It is the object of this invention to provide such a valve in which the closing is accomplished gradually without a sudden jar or jolt, and in which the amount of blow down pressure may be accurately regulated by means of an adjustment.

The invention will be fully disclosed'in the following description taken in connection with the accompanying drawings in which:

Figure 1 is a sectional view along the line 1-1 of Fig. 2; a

Fig. 2 is a vertical section through the axis of the valve, the valve being closed;

Fig. 3 is a view similar to Fig. 2 but showing the valve open.

The casing 10 supporting the movable an other parts of the safety valve is annular in shape and is internally threaded at its lower end for connection to the locomotive or other boiler. On the interior ofthe casing and above the screw threads is an annular flange 11, formed with the central opening 12 through which the excess steam from the boiler escapes when the valve is open. A short cylinder 13 is located above the flange 11 with its axis coincident with the axis of the casing and is connected to the wall of the casing by webs 14, the spaces between the wall ofthe casing 10 and the cylinder 13 serving as steam passages through which the escaping steam is conducted into the mufiler 15, screw threaded t0 the top of casing 10.

Rigid with the cylindrical portion 13 and preferably threaded thereto, is an annular member 16 with a central cylindrical opening 17, the axis of the opening being coin.-

' cident with the axis of the casing- This member constitutes a head for the cylinder 13 and slidably supports with a steamflt,

the stem 18' of the main valve 18..

This main valve 18 comprisesa cylindrical member having an outwardly flaring annular flange 19 at its lower end which is provided with an inclined upwardly facing annular seating surface 20 adapted to seat upon a correspondingly inclined and downwardly facing valve seat 21 on the flange 11 and having rigidly secured thereto a piston 22, slidably fitted to the inner surface 24: of the cylinder 13. The piston 22 is adapted to be moved vertically in the cylinder by the steam admitted thereto to operate the main valve, thereby separating the mutually engaging surfaces 20 and 21 to allow the escape of steam from the boiler.

The main valve is hollow and is formed, as shown with a valve seat 25, the stem 18 above this valve seat 25 having pairs of opposed openings or ports 26 and 27 which serve respectively, as ports through which steam may be admitted to and exhausted from the cylinder 13 above the piston 22.

A pilot valve 28 arranged within the main valve 18 is adapted to cooperate with the seat This pilot valve has an upwardly extending stem 29 having a squared end for a wrench, and a threaded portion near the said end. An adjustable sleeve 30 is threaded upon the shank 29 and extends downwardly, its lower end 31 being arranged to control the ports 27. This portion 31 is in reality a sleeve valve controlling the escape of steam through ports 27 from the balanc ing cylinder, the area of the escape ports at any given instant depending upon the position of the sleeve, and thus upon the position of the pilot valve carrying the same.

The pilot valve is normally held to its seat by means of a coil spring 32, the lower end of which bears against a'shoulder 33' integral with the sleeve 30 and whose upper end rests against a threaded nut 3 1. adjustably secured to the upper end of the main valve by the adjusting nut 35. The position of nut 35 thus controls the degree of compression of thespring 32 and determines the boiler pressure at which the pilot valve opens. The adjusting nut'35 has a series of radial ports 36 therein to permit the escape of steam entering the annular space between the sleeve and the main valve through the port 27, and has an external shoulder. or flange 37 serving as an abutment against -whi ch the comparatively light coil spring 38 bears. This spring 38 rests at its lower end upon the member 16 and normally tends to keep the main valveseated, so that it will not fall or open due to its own weight, when there is no 'steam in'the'boiler.

The lower end 39 of the adjustingnut 35 is directly above theupper end of themember, 16 and these two ends come together when the mainvalve is opened thereby'limiting its downward movement.

With the parts in the position shown in "Fig 2, when the steam pressure in the boiler reaches a predetermined amount the pilot valve is opened against the resistance of spring 321' thus admitting steam into the cylinder above the piston 22 and at the same time the adjustable sleeve 30, whichimoves with the pilot valve, hasbeen raised such a distance that the outlet port 27 for the cylinder is closed or partially closed, depending upon its ad ustment. Steam is then trapped in the cylinder and since the piston -22 has. an area greater than the area of that portion of the main valve which is directly el zposed tothe boiler pressure,'the

entire main valve moves downward, separating-the seating surfaces 20 and 21 and.

allowing steam to escape therebetween through ports 1st into the mullier and thence -reduced and as the boiler pressure is acting on the lower end of the main valve, it is obvious that the latter will seat itself.

This seating of the main valve, however, is not sudden jolt or jar due to unbal ancedupward steam pressure, but is brought about very gradually and takes efiect simultaneously with or slightly in advance of the seating of the pilot valve 28. This is accomplishedby the operation of the adjustable sleeveBOjis exposed totheupward pressure sleeveBO in controlling the escape of steam from; the piston. Asthe pressure in the boiler. gradually decreases the spring32 gradua-lly.clo ses the; pilot .valve and theport 27 is gradually opened thus decreasing the pressure of steam above the piston and gradually; seat ng. the main valve.

lishowever, the lower annular end 40. of

offthe steam; when the pilot valve is open,

- but isnot so exposed when thevalveisclosed it-, followsthat thepilotvalve will not close 'at the; same pressure at which it opened,

-- ibl i at alower pressure, This difierence in I pressu es mevn. as t e b ewown P ess an li heaieeuntotSuch bl W-LlQ HLPrQsSH Q may be regulated by adjustingthe position of the sleeve 30, not to vary the area exposed, but toregnlatethepressure in the balancing cylinder for various positions of the pilot valve, and thus indirectly regulating the blow-down pressure.

Bytri'al adustments of the sleeve 130,.its

most effective position may be determined,

that is, the position which it will occupy relatively to the pilot valve to control the escape of steam fromfthe cylinder whenv the operation of the valve is such that it closes without a jar and when the proper reduction ofboiler pressure has been made. When this position has been; determined, the adjustment is such that upon the gradual closing of the pilot valve due to the upward pressure of the steam thereon gradually becoming less. than the pressure of the spring 32 opposing it, the pressure acting upon the piston to hold the main valve down gradually decreases because of the fact that the orifice through which the steam is passing into the cylinderis becoming more restricted, while the ports .through which it may escape are gradually becominglarger, thereby causing the main valve to seat, the pilot valve however closing sov slowly that the main valve is seated simultaneously with, or, slightly before the pilot valve.

The .device is in no wise complicated or diflicult to construct and provides a novel and convenient means for regulating the blow-down pressure of a boiler. The various parts of the mechanism, Jarticularly the seatingsurfaces 20 and 21 of the main valve are not subjected to great wear as there is nochattering or suddenelosing of the valve.

Having thus described my invention what is claimed as new and desired to be secured by Letters Patent is:

1. In. a safety valve for steam boilers, a

main, valve normally held seated by the ,pressure of steam in the boiler, a cylinder,

a piston in said cylinder and'connectedwith sald main valve, said piston having an area greater than the area of said main valve,

meansfor admitting steam into the cylinder above said plston when the boiler pressure has reached a predetermined amount, to move the same, thereby openingthe main valve, and means for gradually releaslng the steam above said piston as the boiler pressure decreases thereby allowing said main valveto gradually close'andv to seat itself without jarring, said means comprising, a valve which automatically opens as the boiler pressure decreases.

2.111 a safety valve for steam boilers, a

, nain -valve,normally ,held seated; by the pressure of'steam inthe boiler, cylinder, a piston n said cylinderand connected with said main valve,;said piston having an area greater than 'tl16 area 1 of saidrhainvalve, means for admitt ng ;ste ar. r1 into therylinder above said piston when the boiler 'pressure has reached a predetermined amount, to move the same, thereby opening the main valve, and a valve controlling the escape of steam from the cylinder above said piston, the opening in said valve becoming greater as the steam pressure in the boiler becomes less, thereby decreasing the pressure upon said piston and allowing the main valve to gradually seat itself without arring.

3. In a safety valve for steam boilers, a main valve normally held seated by the pressure of steam in the boiler, a cylinder, a piston in said cylinder and connected with said main valve, said piston having an area greater than the area of said main valve, a pilot valve for admitting steam into the cylinder above the piston when the boiler pressure has reached a predetermined amount, to move the same, thereby opening the main valve, and means connected with and automatically operated by said pilot valve for gradually releasing the steam above said piston as the boiler pressure decreases, thereby allowing said main valve to gradually close and to seat itself without jarring.

4:. In a safety valve for steam boilers, a main valve normally held seated by the pressure of steam in the boiler, a cylinder having a port therein, a piston in said cylinder and connected with said main valve, said piston having an area greater than the area of the main valve, a pilot valve for admitting steam into the cylinder above the piston when the boiler pressure has reached a predetermined amount, to move the same, thereby opening the main valve and a valve connected to said means and operated therewith for controlling the port in said cylinder, whereby the ingress and escape of steam into and out of said cylinder are simultaneously regulated, said valve being gradually opened as the pilot valve closes whereby the pressure of the steam acting on the piston is gradually decreased as the boiler pressure decreases and the main valve is allowed to gradually seat itself without jarring.

5. In a safety valve for steam boilers, a main valve having a port therein, a cylinder having a port therein, a piston in said cylinder and connected to said main valve, said piston having an area greater than the area of said main valve, a pilot valve controlling the passage of steam through the port in said main valve and admitting steam into said cylinder when the boiler pressure has reached a predetermined amount whereby the main valve is opened, and a sleeve adjustably secured to said pilot valve and controlling the escape of steam through the port in said cylinder, the pilot valve and sleeve operating together to simultaneously control the inlet and escape of steam into and out of said cylinder whereby the movementt of the piston and main valve is regulated.

6. In a safety valve for steam boilers, an annular main valve having a port therein, a cylinder axially alined with said main valve and having ports therein, a piston in said cylinder and rigidly connected to said main valve said piston having an area greater than the area of said main valve, a pilot valve controlling the passage of steam through the port in said main valve to operate the piston and main valve and adapted to open at a predetermined pressure and to close at a lower pressure, and a sleeve adjustably secured to said pilot valve and controlling the escape of steam through the ports in said cylinder, the pilot valve and sleeve operating together to control the steam pressure in said cylinder by regulating its ingress and exhaust, the outlet port being decreased in area and the inlet port opened by a simultaneous movement of said valve and sleeve in one direction, and the outlet port being increased in area and the inlet port decreased in area by a movement of said valve and sleeve in the opposite direction, the main valve being opened upon the first mentioned movement taking place and being gradually closed upon the movement in the opposite direction.

7. In a safety valve for steam boilers, a main valve normally held seated by the pressure of steam in the boiler, a cylinder,

- a piston in said cylinder and connected with said main valve, said piston having an area greater than the area of said main valve, means for admitting steam into the cylinder above said piston when the boiler pressure has reached a predetermined amount, to move the same, thereby opening the main valve, and means for gradually releasing the steam above said piston as the boiler pressure decreases thereby allowing said main valve to gradually close and to seat itself without jarring.

In testimony whereof I affix my signature.

WVILLIAM F. KIESEL, JR.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of JPatents.

Washington, D. 0."

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