US2001686A - Fusible safety device - Google Patents

Description

May 14, 1935- R. H. MOORE ET AL 2,001,686

FUSIBLE SAFETY DEVICE Filed April 23, 1952 water boilers and the like.

Patented May 14, 1935 UNITED STATES FUSIBLE SAFETY DEVICE Robert H. Moore and Russell B. Allen, Lexington,

Mass., assignors to J. W. Moore Valve Corporation, Everett, Mass., a corporation of Massachusetts Application April 23, 1932, Serial No. 607,112

3 Claims. (Cl. 122504.1)

Our present invention relates to valves, and moreparticularly to a novel and improved relief valve, adapted for use in conjunction with he An important object of the present invention resides in the provision of a pressure relief-valve wherein an accurate and sealing fit of the valve on its seat will be at all times assured, regardless 'of the type of valve utilized, and which valve will automatically relieve at a predetermined pressure, draininga sufficient quantity of water to 736- lieve the pressure and keep the same within the bounds of safety, and thereupon will automati cally reset itself with the same sealing fit, thus obviating any likelihood of leakage at the valve seat.

Another object of the invention resides in a novel combined pressure and temperature relief valve, Which may be set to relieve either at a predetermined pressure, or at a predetermined temperature. I y

Another feature of our present invention resides in the fact that independent outlets are provided for water discharged through the above two valves, thus obviating the necessity of wator discharged through the temperature valve travelling through the pressure valve chambers, with the possible resultant disadvantages of fouling the pressure valve mechanism with sediment, rust or other foreign matter.

A further object of our invention resides in the provision of a novel temperature relief valve, having several features of novelty and utility, and presenting a marked advance in this art over any prior devices of this nature of which we are aware.

The valve closure element of our novel temperature relief element comprises a plug of fusible metal adapted to melt at a predetermined temperature, and a further object of this invention resides in our novel fusible plug carrier, and its adaptation to 'a temperature relief valve.

A still further feature of this invention resides in the provision, in said carrier, of means to accommodate and carry a spare or replacement fusible plug, remote from the effect of the hot water within the valve so that said replacement plug will be unaffected regardless of the water temperatures created within said valve. The advantages of this last mentioned feature will be instantlyapparent, not only to those skilled in this art, but to householders and others upon whom the duty of replacing a melted plug revolves This last named feature is made possible by the 65 construction of our novel carrier and of the valve body wherein'is located the seat for the fusible plug. On melting of the fusible plug, a discharge orifice is opened to the water within the valve body, permitting its discharge therethrough into a suitable drain without travelling through the 5 fuse carrier as is necessary in many prior types of temperature relief valves.

Our present valve is simple to manufacture and assemble, economical, strong and rugged, and yet is efficient and accurate to within extremely fine limits of adjustment, and since we believe that thesame is novel, we have claimed the same in this application.

Other objects and features 'of the present invention reside in the particular construction and 15 arrangement of our novel valve and its parts, and all of the above, together with other objects and features of the invention, details of construction, combinations of parts and advantages, will be hereinafter more fullypointed out, described and claimed. 7

Referring to the drawing, illustrating'preferred embodiments of our invention, Fig. l is a vertical sectional view on the line I-I of Fig. 2; illustrating our novel combined pressure and temperature relief valve;

Fig. 2 is a side elevation of our valve;

Fig. 3 is a fragmentaryvertical sectional view illustrating a slightly modified valve seating mechanism; I

Fig. 4 is a verticalsectional view illustrating a slightly modified type of pressure relief valve; and

Fig. 5 is a fragmentary sectional view illustrating our novel fusible plug carrier.

Referring now to the drawing for a particular description of the invention, its construction, assembly and operation, l designates a valve body having therein a chamber 2' within which is located the pressure relief valve mechanism. Said 40 body is provided, in this chamber, with female threads 3 in which is threaded a screw washer 4, said washer constituting a guide for the upper end of the valve stem 5 which has at its-lower end a cup-shaped portion 5 in which is-seated the valve washer 1 adapted to engage the'valve seat 3. vSaid washer l is retained in its holder by means of a nut 9 having a threaded stem l0 screwed into the valve stem 5. Said nut projects into the orifice l l below the valve seat 8 and con- 50 The collar I2 has "a bore somewhat greater than the diameter of the valve stem to permit rocking of said collar relative to said stem. Confined between the screw washer 4 and valve collar I2 is a coiled spring I4 having a flat or squared top and bottom, as clearly illustrated in Fig. 1. The washer 4 and collar I2 are provided with flanges I5 and I6 respectively to maintain said spring in proper position and alinement. The open end of the chamber 2 is sealed by a cap II threaded into the threads 3. The chamber 2, through the orifice II, communicates with 8 chamber I8 in the lower end of the body I, said lower end being externally threaded as at I9 for attachment to a standard or suitable tapping in the boiler or tank of a hot water system, for example, This valve will be applied to said boiler at the point where the temperature of the water, and hence the pressure, is the highest, aswill be readily understood. The body I isprovided with a discharge port 20 communicating with the outlet 2,I in the neck 22, said neck being adapted for connection to any suitable drain.

The valve as. thus far describedis entirely a pressure relief valve, and the valve I is adapted to be raised from its seat 8 at such time as the Pressure in said boiler reaches a predetermined point. The raising of the valve I is of course against the pressure of the spring I4, and said spring I4 may be adjusted toany desired or predetermined pressure by means of the screw washer 4. The action of this valve is entirely automatic, and, assuming that the predetermined pressure has been created, the valve I will be raised from its seat 8, and the water will be discharged through the orifice II into the chamber 2, and thence through the discharge port 20 and outlet 2|, into any suitable drain.

As soon as the pressure has been relieved and has dropped toa point commensurate with the requirements of safety, the spring I4 will force thevalve 1 down on its seat 8, again sealing the device until such time as the pressure within the boiler or tank to which the valve is attached reaches the above mentioned predetermined degree, Movement of the valve I in a longitudinal path is insured by the collar I2 and its radius I3, with the squared end of the spring I4 bearing thereagainst. The pressure of the spring I4 against said collar I2, and the fact that said collar is free to rock relatively to the valve stem.

5, coupled with the further fact of thepresence of said radius I3, will insure a direct pressure on the valve 1 along the longitudinal axis of the valve. This insures against cocking of the valve 1, or any other condition which might prevent an instantaneous, accurate and sealing fit of the valve Ion its. seat 8, and insures further an emcient, leak-proof valve construction.

Referring now to Fig, 4, we have illustrated a slight modification of valve, incorporating the principles explained with respect to the valve of Figs. 1v and 3. In this modification, we sub-v stitute for the valve I, a ball valve 23 enga ing theseat 24 at the top of the chamber I8. In this modification the valve stem 25 is provided at its lower end with a button 26 corresponding to the collar I2, said button having a radius 21 corresponding to the radius I3. Said valve stem 25' also hasa thickened portion 28 corresponding to the flange I6 for proper alinement of the spring surface. of the button 26. and against the lower face of the screw washer 4.

It will thus be readily apparent that, when the ball 23 has been raised from its seat 24 by pressure, as soon as said pressure has been relieved to a suitable extent, said ball will be forced downwardly with a true fit on its seat 24, regardless of any tilting or rocking of the valve stem 25, as the radius 21, coupled with the spring construction above described, will insure a. pressure on said ball at a point directly in line with the central longitudinal axis of the device.

. The advantages, simplicity, efliciency, accuracy, and fine limits of adjustment of our novel pressure relief valve will be instantly apparent to and understood b! those skilled in this art.

Referring again to Fig. 1, the valve body I is provided with a discharge port 29 communicating with and interconnecting the chamber I8 and Outlet 2I, said discharge port constitutinga seat for a plug 30 of fusible metal, said port 29 having tapered walls and the plug 30 being of frustoconical shape to insure a tight wedging fit of said plug in said port, as will be further described. The fusible plug 30 has areduced end 3| adapted to seat in a terminal recess 32 in one end of. the plug carrier 33, said carrier having a threaded portion 34 for threading into the threaded aperture or tapping 33 located in the valve body I at a point diametrically opposite the port 29. The carrier 33 is provided with a head 35 havlnga slot 31 for manipulation of the carrier by a screwdriver, coin or other suitable device. The. head 36 is of a greater diameter than any other part of the carrier 33 and is adapted to seat in a recess 38 formed in the body I, a soft washer 39. being located in said recess to afford a watertight joint when the carrier 33 is screwed in position.

The carrier 33, plug 30 and head 36. are. so proportioned that when said carrier threaded into the aperture 35 and the. head 35 has com pressed the washer 39 to a water-tight condition, the plug 30 will be forced, jammed or wedged in its port 29 to prevent leakage therethrough.

It will thus be appreciated that the carrier. 33.

is accessible externally of the valve body I for. removal in the event that it is desired to replace the plug 30, and that this removal may be effected without removal of any other part of the device and without disassembling or dismantling the valve. It will also be. apparent that there moval and replacement of said carrier may be effected without in any way disturbing the pressure valve mechanism, this latter being a feature of great importance, as the. pressure setting re.- mains constant regardless of any manipulation of the temperature relief mechanism. 7

When the temperature of the water in the chamber I8 attains a. degree sufficient to. melt the plug 30, which degree will of course-be below the danger. point, said plug will melt and the water will be discharged through the port 29 intothe outlet 2| and thence to a drain withoutcom municating with the chamber 2 and the pressure relief mechanism contained therein. After melting of the fusible plus; 30. it is the work ofbut a. few moments to withdraw the carrier 33, replacethe melted plug with anew one, and reinsert the.

carrier in the valvebodv with the parts in propersealing position.

The advantages, simplicity, economy and em.

ciency of our novel-temperature relief. valve will be instantly apparent. By this construction we. have greatly reduced the cost of plug replacements, as the only part reqniredto be replaced being suitable.

is. the plug 30;.itself, the carrier 33 and adapted for continuous use throughout the life of the entire device.

Referring now to Fig. 5, we have illustrated an additional feature in conjunction with our fuse carrier. In this embodiment of the invention, the fuse carrier 40 is provided with a terminal recess 4| to receive the fusible plug 42, in every way similar to the recess and plug 32 and 30 respectively. The carrier 40 is provided with a threaded shank 43 for threading into the tapping 44 in the valve body I, exactly similar to the threaded aperture or tapping 35. In place of the head 36, however, we provide, on the carrier 40, a head 45 projecting into the outer air and having a chamber 46 therein in which is adapted to be housed a fusible plug 41 adapted to replace the plug 42 in the event that the latter becomes melted. Means, such as the slots 48, is provided for threading of the carrier into, the body I, and means, such as the cotter pin, tag wire or the like, 49, extending through diametrically opposed apertures 50, is provided to constitute retention means for the replacement plug 41. It will be noted that the chamber 46 is open to the outer air, to permit circulation of said air in said chamber and around said replacement plug 41, to overcome the eifect of any heat which might be radiated through the metal of the valveto the said plug 41. Theapplication of the carrier 40 to the valve body, and the wedging of the plug 42 in its port 29, together with the sealing of the tapping 44 by the washer 5|, is identical with the application of the carrier 33, as will be readily understood.

'In the event that other means than the cotter pin 49 is utilized to retain the spare plug 41 in its chamber 46, for example such as a cap or the like to close the end of said chamber, we provide perforations through the head 45 for free circulation of air therethrough.

This feature of'providing a replacement plug, in a readily accessible position, and in the carrier itself, greatly facilitates the replacement of a melted plug, an advantage that will be instantly apparent to all concerned. Since we believe that our plug carrier, constructed and arranged as above briefly described, is novel, we have also v claimed said carrier in this application.

In Fig. 3 we have illustrated the valve stem provided with a button I2a and a thickened portion IGa in place of the collar I2 and flange 16. This construction is similar to the valve stem 25 in Fig. 4. The cup-shaped valve holder 6 is provided with an arcuate upper surface 52 engaged by the radius I3 on the button l2a. In this form of the invention the operation will be the same as the action of the button 26 against the ball 23, and results in a true longitudinal pressure being constantly exerted against the soft valve 1-, insuring a tight, accurate, sealing fit against its seat 8.

may

While we have necessarily described our present invention somewhat in detail, it will be appreciated that we may vary the size, shape and arrangement of parts within reasonably wide limits, without departing from the spirit of the invention.

We claim:

1. A relief valve comprising a body having a chamber therein and a'liquid discharge outlet leading therefrom, a fusible plug in said discharge outlet adapted to melt at a predetermined temperature in said chamber, a carrier for said plug, said body having an opening therein communicating with said chamber diametrically opposite said discharge outlet for insertion and removal of said carrier and plug, and means cooperating with said carrier to seal said opening, said carrier and plug being so proportioned-that when said opening is sealed by said carrier, said plug will have a sealing fit in said carrier having a recess therein remote from said chamber and adapted to house a similar fusible- Plug.

2. A relief valve comprising a body having a chamber therein and aliquid discharge outlet leading therefrom, a fusible plug in said discharge outletadapted to melt at a predetermined temperature in said chamber, arcarrier for said plug, said body having an opening therein communicating with said chamber diametrically. opposite said discharge outlet for insertion and removal of said carrier and plug, means cooperating with said carrier to seal said opening, said carrier and plug being so proportioned that when said opening is sealed by said carrier, said plug will have a sealing fit in said discharge outlet, said carrier having a recess therein remote from said chamber and adapted to house a similar fusible plug, and retention means to prevent inadvertent removal of said second plug. v

3. A' relief valve comprising a body having a chamber therein and a liquid discharge outlet leading therefrom,a fusible plug in said discharge outlet adapted to melt at a predetermined temperature in said chamber, a carrier for said plug, said bodyhaving an opening therein communieating with said chamber diametrically opposite discharge outlet, said said discharge outlet for insertion and removal of said carrier and plug, means cooperating with said carrier to seal said opening, said carrier and plug being so proportioned that when said opening is sealed by said carrier, said plug will have a sealing fit in said discharge outlet, a portion of said carrier projecting beyond said valve body and having a recess therein adapted to house a similar fusible plug, and means to prevent inadvertent removal of said second plug, said recess communicating with the outer air for circulation of said air around said second plug.

- ROBERT H. MOORE. RUSSELL B. ALLEN.

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