US3227170A - Fusible safety valve mounting - Google Patents

Description

Jan. 4, 1966 L. J. SIGL 3,227,170

FUSIBLE SAFETY VALVE MOUNTING Filed May 20, 1963 2 Sheets-Sheet 1 INVENTOR.

Jan. 4, 1966 Filed May 20, 1965 L. J. SIGL FUSIBLE SAFETY VALVE MOUNTING 2 Sheets-Sheet 2 INVENTOR law/s J. 5/64 A TTOQA/E Y5 United States Patent 3,227,170 FUSIBLE SAFETY VALVE MOUNTING Louis J. Sig], 1088 Colvin Ave., Kenmore, N.Y. Filed May 20, 1963, Ser. No. 281,494 4 Claims. (Cl. 137-73) This invention relates to safety devices for boilers or other apparatus subject to heat and pressure and more particularly, to safety valves associated with such apparatus in a novel manner.

Safety valves for boilers and similar apparatus are of course well known. Such safety valves are subject to operational failure for various reasons, especially after long periods when the necessity for operation of the valve has not arisen. In such cases the valve itself may become stuck to the seat by corrosion, the valve mechanism may become fouled by foreign matter such as dirt or the like, and may fail to operate when required and at the desired pressure for various other reasons.

Such safety valves are commonly provided with means for manually causing the valve to raise from its seat for testing purposes but such testing may be neglected and, even if periodically tested, there is no assurance that the valve will operate at the desired pressure. Furthermore, due to low liquid in a boiler, for instance, excessive temperatures may be attained without the presence of a proportionately high steam temperature within the boiler or, more particularly, at the region of the boiler where the safety valve is located.

A further possible objection to safety valves as presently constructed and arranged resides in the fact that, even when it operates entirely as intended, a conventional safety valve merely relieves excessive pressure and then re-closes, leaving no clear or permanent indication that a condition requiring safety valve operation has existed.

The present safety valve construction and mounting is such that when a predetermined limit temperature occurs at the safety valve, the safety valve becomes entirely dis.- sociated from the boiler or other apparatus to which it is normally connected. This occurs through fusion of material which intervenes between the apparatus proper and the safety valve and thus forms a mounting connection therebetween.

In boilers and similar apparatus temperatures and pressures are closely related and therefore, generally, unduly high boiler pressures and unduly high temperatures go hand in hand. With the safety valve mounting of the present invention, if the safety valve fails to open at a predetermined undue pressure, the low melting alloy which connects the safety valve proper with the boiler fuses and the pressure thereagainst from within the boiler forces the entire valve structure from its mounted position. A further feature of the apparatus of the present invention resides in the provision of means for automatically shutting off the supply of fuel to the boiler when an abnormal condition is reached and the Safety valve either opens under pressure from the boiler or becomes dissociated therefrom by fusion of the low melting alloy portion of the safety valve mounting.

This may be accomplished by biasing a fuel valve or other fuel control member to closed position by a spring or the like and providing a connection between the fuel valve of fuel control member and the valve element of the safety valve. In a further modification the connection to the fuel valve or other energy-supply control means leads from a fusible connection element which is disposed in the safety valve beyond the valve element thereof, so that the fusible connection is exposed to escaping steam when the safety valve opens.

Thus in either modification if the valve element opens or if the valve assembly becomes dissociated from the 3,227,170 Patented Jan. 4, 1966 boiler it releases the force which holds the fuel valve or fuel control member in open position, whereupon the fuel valve or fuel control member immediately closes. In the modification which includes a fusible connection which is exposed to steam when the safety valve opens, the melting of this connection serves as a permanent indication that the safety valve has opened.

Several mechanical embodiments of the principles of the present invention are illustrated in the accompanying drawings and described in the following specification. However, it is to be understood that such embodiments are by way of example only and that various mechanical modifications may be made therein without departing from the principles of the invention, the scope of which is limited only as defined in the appended claims.

In the drawings:

FIG. 1 is a vertical longitudinal cross-sectional view through one form of the safety valve of the present invention mounted upon a boiler or similar apparatus and with a-fuel control valve shown in association therewith; and r FIG. 2 is a similar view of a modified form of the safety valve construction of the present invention.

In FIG. 1 of the drawing, the numeral 10 designates a steam boiler or similar apparatus such as a hot water heater, and the numeral 11 designates a safety valve main housing member having a cup-shaped upper portion 12 and a reduced mounting sleeve portion 13. A connection member designated generally by the numeral 14 comprises a lower threaded portion 15 which threads into the wall of the boiler 10 and an upper sleeve portion 16 which receives the stem 13 of safety valve housing 11 loosely, whereby a relatively thin bushing of low melting alloy 17 may be interposed therebetween. A nut formation 18 on connection member 14 is provided for securing the same to the boiler.

The remainder of the construction of the safety valve per se is more or less conventional. Stem portion 13 terminates at its upper end within the cup-shaped portion 12 in a fiat radial valve seat and a valve member 20 normally seats thereon, in which position the passage 21 through stem 13 which leads from the interior of boiler 10 is closed. A vented cap member 23 is threaded into the upper end of cup-shaped portion 12 of valve housing 11 and bears against the upper end of a compression coil spring 24 which normally holds the valve in closed position.

A stem member 26 is connected at its lower end to valve element 20 and extends upwardly through the cap member 23. As is conventional, a lever member 27 is pivoted to stem 26 as at 28 and may be manually pivoted in a counterclockwise direction as viewed in the drawing to forcibly lift the valve element 20 from its seat for testing purposes.

In the drawing, the numeral 30 designates a fuel supply line which may supply gas or fuel oil to the burner which fires boiler 10. The numeral 31 designates a valve interposed in such fuel line and, in the illustrated instance, the valve moves in a counterclockwise direction to open position and in a clockwise direction to closed position. An extension coil spring 32 acts against an arm 33 connected to the valve element of valve 31 to urge the valve element to closed position while a wire or similar connection 34 connects between the top of stem 26 and an arm 35 likewise pivotally movable with the valve element of valve 31.

From the foregoing it will be noted that opening movement of valve 20 in the usual fashion by reason of excessive pressure thereagainst from passage 21 relaxes the tension in wire 34 whereupon spring 32 closes the fuel valve.

H lfn-the valve failsto open-at a desired pressure by reason of malfunction, the excessive temperature accompanying such excessive pressure will fuse bushing 17 and'the pressure'upwardly against the valve assembly will cause the stem 13 to move outwardly of the sleeve porton 16 of mounting member 14. This releases the pressure inthe boiler and likewise relaxes the tension of wire 34 which also closes fuel valve 31 as described above.

Aneffective method of forming the soft metal bushing 17 and causing the same to provide a secure joint between sleeve portion 13 and the sleeve portion 16 of connection member '14 is to first prepare the interior of sleeve portion 16 and the exterior of sleeve portion 13 by tinning, that is, applying a thin coating of solder to these surfaces. The parts are then assembled and molten solder or other alloy having the desired melting point is poured into the radial space between the sleeve portions 13 and 16 to form bushing 17 which is thus securely bonded or fused to the adjacent sleeve surfaces.

Reference will now be had to the embodiment illustrated in FIG. 2 wherein the numeral 40 designates a steam boiler or analogous apparatus and the numeral 41 designates a generally conventional safety valve housing member comprising an upper valve chamber portion 42 and a reduced external threaded mounting nipple portion 43. Aconnection member designated generally by the numeral 44 comprises a lower threaded portion 45 which threads into the boiler 10 and an upper sleeve portion 46 which receives a lower sleeve portion 45 of an internally'threaded valve housing mounting member 48.

It will be noted that the sleeve portion 47 of the mounting member 48 fits loosely within the upper sleeve portion 46 of connection member 44 and, as in the case of the previous embodiment, a relatively thin annular layer of low melting alloy50 is interposed in the space between the sleeve portions 46 and 47.

The remainder'of the safety valve construction is generally conventional with the exception of a further thermal connection element which will be described presently. The mounting nipple portion 43 terminates at its upper end within the valve chamber housing portion '42 in a flat radial valve seat and a valve'member 52 normally seats'thereon, in which position an axial passage 53 from the interior of boiler 40 is closed. A cap member 55 threads into the upper end of housing portion 42 and bears against the upper end of a compression coil spring 56 which normally holds valve 52 in closed position.

A stern member 60 is connected at its lower end to valve element 52 and extends upwardly through the cap member 55. As in the previous embodiment, a valve testing lever. 62 is pivoted to the upper end. of stem member 60.

. Again as inthe previous embodiment, afuel supply line designated 65'has disposed therein a globe type shutoff valve 66 which is normally biased to closed position by. an extension coil spring 67 acting through an arm 68 fixed to the pivoted valve element of the globe valve 66. A further. arm 69 likewiseconnected to the valve element of valve;66 has a wire or similar connection 70 leading to afusible connection means designated generally by the numeral 71 anddisposed within an outlet passage portion 72 of safety valve 41.

The fusible connection means 71 comprises a tubular member 74 open at its upper end and connected at its lower end tothe wall ofpassage portion 72 by a screw eye 75. A rod 77 extends loosely into tubular member 74 and is connected at its upper end to wire 70. An annular layer of fusible material 78 normally bonds the rod 77 to the interior of tubular member 74 and thus holds fuel valve 66in open position by exerting thereon a counterclockwise rotative force against the resistance of spring 67.

The valve mounting arrangement illustrated in FIG. 2 operates in substantially the same manner as that of the previously described embodiment illustrated in FIG. 1.

Cir

If valve 52 fails to open at a desired pressure for any reason, excessive temperature fuses the low melting alloy 50 and upward pressure against the valve assembly causes the mounting member 48 and the valve carried thereby to move outwardly, that is upwardly as viewed in FIG. 2. This releases the pressure in the boiler and likewise relaxes the tension of wire 70 whereupon spring 67 closes the fuel valve.

If excessive pressure is reached in the boiler and the safety valve does function in the expected manner by opening of valve element 52, the escaping steam through passage 72 rapidly raises the temperature of the annular alloy filling 78 of fusible connection 71 which releases rod'77 from tubular member 74. Thus the fuel valve 66 is closed either by melting of the fusible joint at '50 or by normal operation of the safety valve under excessive pressure.

Note that an opening 80 in passage portion 72 permits rod'77 and its connection with wire 70 to move freely upwardly upon melting of the material 78 to permit free closure of valve 66 under such circumstances. In this embodiment of the invention means are provided for giving a more or less permanent indication that the safety valve has operated, even though the valve member 52 thereof subsequently closes. This indication remains by reason of the separation of rod 77 from tubular member 74.

I claim:

1. In a safety valve arrangement for fluid heating vessels subject to elevated pressures and temperatures, a tubular'member adapted to be fixed at one end to such vessel in fluid communication with the interior of the vessel, a safety valve having a mounting stem portion including a' pressure inlet passage to said safety valve and a valveelement openable upon predetermined pressure in said inlet passage, said mounting stem and said tubular member being in telescoping relation with a radial space therebetween, and a low temperature alloy in said radial space and bonded to said stem and said tubular member to normally connect the same against relative axial movement, said alloy being fusible at a predetermined temperature torelease said sleeve from said tubular member to disconnect the safety valve from said vessel, means for controlling the supply of'heating energy to said vessel, means biasing said control means to a position for preventing such energy supply, and holding means'between said valve element and said control means for holding said control means in energy supplying position when said valve is in normal seated position, said holding means being responsive to either movement of said valve element to an open position or disconnection of the safety valve from said vessel to release said control means for movement to energy supply preventing position, whereby said control means moves to energy supply preventing position when said valve element moves toward open position or said fusible alloy releases said safety valve from said vessel.

2. In a safety valve arrangement for fluid heating vessels subject to elevated pressures and temperatures, a tubular member adapted to be fixed at one end to such vessel with the interior of the tubular member in fluid communication with the interior of the vessel, a safety valve housing including a valve chamber and a pressure inlet sleeve opening into said chamber, a valveelement normally closing communication between said sleeve and said chamber, spring means for 'yieldably holding said valve in closed position, said pressure inlet sleeve telescoping within said tubular member and spaced radially inwardly therefrom, and a low temperature alloy in said radial space and fused to said sleeve and said tubular member to normally connect the same against relative axial movement, said alloy being fusible at a predetermined temperature to release said sleeve from said tubular member, means for controlling the supply of heating fuel to said vessel, means biasing said control means to a position for preventing such fuel supply, and tension holding means between said valve element and said control means for holding said control means in fuel supplying position when said valve is in normal seated position, said holding means being responsive to either movement of said valve element to an open position or disconnection of the safety valve from said vessel to release said control means for movement to energy supply preventing position, whereby said control means moves to fuel supply preventing position when said valve element moves toward open position or said fusible alloy releases said safety valve from said vessel.-

3. In a safety valve arrangement for fluid heating vessels subject to elevated pressures and temperatures, a tubular member adapted to be fixed at one end to such vessel with the interior of the tubular member in-fluid communication with the interior of the vessel, a safety valve housing including a valve chamber and a pressure inlet sleeve opening into said chamber, a valve element normally closing communication between said sleeve and said chamber, spring means for yieldably holding said valve in closed position, said pressure inlet sleeve and said tubular member being in telescoping relation with an annular space therebetween, and a low temperature alloy in said radial space and bonded to said sleeve and said tubular member to normally connect the same against relative axial movement, said alloy being fusible at a predetermined temperature to release said sleeve from said tubular member, means for controlling the supply of heating energy to said vessel, means biasing said control means to a position for preventing such energy supply, and holding means between said valve element and said control means for holding said control means in energy supplying position when said valve is in normal seated position, said holding means being responsive to either movement of said valve element to an open position or disconnection of the safety valve from said vessel to release said control means for movement to energy supply preventing position, whereby said control means moves to energy supply preventing position when said valve element moves toward open position or said fusible alloy releases said safety valve from said vessel.

4. In a safety valve construction for boilers and like vessels subject to elevated pressures and temperatures, a tubular member adapted to be fixed at one end to such vessel in fluid communication with the interior of the vessel, a safety valve having a mounting stem portion including a pressure inlet passage to said safety valve, said mounting stem and said tubular member being in telescoping relation with an annular space therebetween, a low temperature alloy in said annular space and bonded to said stern and said tubular member to normally connect the same against relative axial movement, said alloy being fusible at a predetermined temperature to release said stem from said tubular member to disconnect the safety valve from said vessel, means for controlling the supply of heating energy to said vessel, means biasing said control means to off position, and holding means extending between said safety valve and said control means normally holding the latter in on position, said holding means being responsive to either movement of said valve element to an open position or disconnection of the safety valve from said vessel to release said control means for movement to energy supply preventing position, said holding means including a fusible connection located in the path of escaping steam when said safety valve is open, whereby said control means moves to off position either when said safety valve opens and said fusible connection melts or when the low temperature alloy in said annular space melts.

References Cited by the Examiner UNITED STATES PATENTS 1,142,902 6/1915 McNutt 137-74 X 1,868,708 7/1932 Hunt 137-75 2,036,391 4/1936 Bradley 13774 X 2,194,541 3/1940 Buttner l37--73 2,410,900 11/1946 Radbill l22--504.1

ISADCR WEIL, Primary Examiner.

R. GERARD, Assistant Examiner.

Claims (1)

1. IN A SAFETY VALVE ARRANGEMENT FOR FLUID HEATING VESSELS SUBJECT TO ELEVATED PRESSURES AND TEMPERATURES, A TUBULAR MEMBER ADAPTED TO BE FIXED AT ONE END TO SUCH VESSEL IN FLUID COMMUNICATION WITH THE INTERIOR OF THE VESSEL, A SAFETY VALVE HAVING A MOUNTING STEM PORTION INCLUDING A PRESSURE INLET PASSAGE TO SAID SAFETY VALVE AND A VALVE ELEMENT OPENABLE UPON PREDETERMINED PRESSURE IN SAID INLET PASSAGE, SAID MOUNTING STEM AND SAID TUBULAR MEMBER BEING IN TELESCOPING RELATION WITH A RADIAL SPACE THEREBETWEEN, AND A LOW TEMPERATURE ALLOY IN SAID RADIAL SPACE AND BONDED TO SAID STEM AND SAID TUBULAR MEMBER TO NORMALLY CONNECT THE SAME AGAINST RELATIVE AXIAL MOVEMENT, SAID ALLOY BEING FUSIBLE AT A PREDETERMINED TEMPERATURE TO RELEASE SAID SLEEVE FROM SAID TUBULAR MEMBER TO DISCONNECT THE SAFETY VALVE FROM SAID VESSEL, MEANS FOR CONTROLLING THE SUPPLY OF HEATING ENERGY TO SAID VESSEL, MEANS BIASING SAID CONTROL MEANS TO A POSITION FOR PREVENTING SUCH ENERGY SUPPLY, AND HOLDING MEANS BETWEEN SAID VALVE ELEMENT AND SAID CONTROL MEANS FOR HOLDING SAID CONTROL MEANS IN ENERGY SUPPLYING POSITION WHEN SAID VALVE IS IN NORMAL SEATED POSITION, SAID HOLDING MEANS BEING RESPONSIVE TO EITHER MOVEMENT OF SAID VALVE ELEMENT TO AN OPEN POSITION OR DISCONNECTION OF THE SAFETY VALVE FROM SAID VESSEL TO RELEASE SAID CONTROL MEANS FOR MOVEMENT TO ENERGY SUPPLY PREVENTING POSITION, WHEREBY SAID CONTROL MEANS MOVES TO ENERGY SUPPLY PREVENTING POSITION WHEN SAID VALVE ELEMENT MOVES TOWARD OPEN POSITION OR SAID FUSIBLE ALLOY RELEASES SAID SAFETY VALVE FROM SAID VESSEL.

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