US2213528A - Thermal relief valve - Google Patents

Description

Sept. 3, 1940. E. R. LOWE THERMAL RELIEF VALVE Filed May 7, 1938 www lfm/wa ATTORNEYS. f

Patented Sept. 3, 1940 2,213,528 THERMAL RELIEF VALVE Ernest A. Lowe, Fanwood, N. J., assignor to The Airelease Corporation, Jersey City, N. J., a corporation of Delaware Application May 7, 1938, Serial No. 206,548

11 Claims.

This invention relates to automatic fire extinguishing systems designed to automatically discharge a` fire extinguishing iiuid, such as water, to a rire for extinguishing purposes. In its application, it is preferred to apply the invention to what is known in the art as a dry-pipe system, to wit: one in which the liquid distributing system preferably comprises a riser pipe connected to a source of fluid supply and branch or distributing pipes which are connected with the riser. The riser and distributing pipes are either empty or filled with compressed air which normally is retained Within the system by means of closed fusible sprinkler heads mounted at intervals on the branch or distributing pipes. The discharge of the extinguishing medium from the sprinkler heads usually only is permitted when one or more of them fuses by the action of heat generated by a fire in order to open the head and to permit the extinguishing fluid to flow thereto`v for discharge therefrom.

As is well known, one of the objections to a dry-pipe system, especially one in which the riser and distributing pipes are normally lled with compressed air, is the delay, which ordinarily must ensue, in having the extinguishing uid available at the sprinkler head for immediate discharge therefrom. In a typical dry-pipe system, before the extinguishing fluid is available for discharge, a sprinkler head must first fuse and open and air must then be forced from the pipes intervening between the inlet valve and the open sprinkler head. This delay ordinarily makes it possible for the fire to progress to an extent sufficient to cause considerable fire damage before the system is brought into operation. The principal object of the invention, with the above explanation in view, is the production of a thermaly relief valve of improved construction adapted to operate on a sudden rate-of-rise of temperature such as would be produced on the occurrence of a fire so that, by its action, it is adapted to condition the system with the extinguishing fluid', that is, it permits the system to be relieved of air pressure and to be filled with the extinguishing fluid which flows to, or in proximity to, the sprinkler head or heads whereby it is accessible for instant discharge therefrom upon the fusing of and consequent opening of 'said sprinkler head or heads. The invention therefore permits the conversion of what is ordinarily a dry-pipe system into a wet-pipe system with its many attendant advantages;

A further object of thev invention is the pro*- vision of a thermal; relief valve of simple con;-

(Cl. 16S- 17) struction Which shall be adapted, and in furtherance of the above objects, to be readily applied to any conventional form of dry-pipe extinguishing system now in use and at small-expense and without any general reorganization or modifica- 15 tion of the system per se.

The invention is an improvement .on the invention of my prior application for patent for Thermal relief valve, led June 12, 1936, Ser, No. 84,816 in which the advantages of a device of I10 this general character are set forth in great detail and many of which do not require repetition or amplication in this specification, further objects and advantages of the invention of the improved device being apparent from the sub- 15 joined description taken inr connection with the accompanying drawing in which:

Fig. 1 is a side elevation of a fragmentary portion of a conventional form of dry-pipe iire extinguishingl system showing the present in- 20 vention as used in conjunction therewith.

Fig. 2 is a vertical central section `taken through the thermalrelief valve; and

Fig.` 3 is a horizontal section taken on the line 3 3 of Fig. 2`. l ,25

Referring in detail to the several figures of the The riser pipe .of a conventional dry-pipe fire extinguishing system is indicated at l' and it is provided with one or more branch or distribut- 1,30 ing pipes connected at intervals therewith' which are mounted preferably adjacent the ceiling l2 of a room or other enclosure. These branch or distributing pipes Il are supplied at spaced intervals thereon with normally closed sprinkler '.*35 heads I3 having fusible links adapted to fuse to automatically open the heads When'heat of a sufficient degree has been attained as, for instance, by that caused by a re. The system is ordinarily lled with air under pressure which '40 must be permitted to escape upon the occurrence of a fire to be replaced by the fire extinguishing medium, such as water, which normally is excluded from the system by an automatic main dry valve shown diagrammatically at "l5 45 and Which'm-ay be of any suitable type and construction. The main dry valve is normally `held closed by the pressure of the compressed air in the system exerted thereagainst to prevent the passage vof the extinguishing fluid from a `source `50 of supply to' the distributing system. l

In some cases it is desirable to employ an exhauster or accelerator I6 also shown diagrammatically and employed forV detecting the de- GTCELSG in air pressure in thesystem occasioned by fire conditions and also to hasten the discharge of air from the system. Any form of alarm or other signal, such as the bell indicated at I1, may be employed in association with the dry valve I5 to give a signal when the system is becoming lled with water or other re extinguishing iiuid. A suitable gate valve operable by hand is indicated at I8, its function being to control the ow of water or other extinguishing medium from a water or fluid main I9 or other source of supply.

As is usual in this type of apparatus, the dry valve I5 requires an appreciable loweringjof the air pressure in the system before it will operate and accordingly it is necessary .for one of theV sprinkler heads I3 to fuse and open to permit the escape of compressed air from the system and allow the automatic opening of said dry valve I5 by the release of pressure thereagainst. By use of the present invention the dry valve is permitted to open in advance of the fusing of a sprinkler head and to thereby obviate the various objections inherent in the old type of apparatus. This automatic opening of the dry valve and the 'escape of the compressed air from the system permits of the replacement of the air by water or other extinguishing fluid in the system so that Ywhen a sprinkler head finally opens from the heat generated by a re, the extinguishing medium will be immediately available at the ysprinkler head to be instantly discharged therefrom. The sprlinkler heads I3, as illustrated, extend upwardly toward the ceiling and a T-connection 20 is preferably interposed therebetween and the distributing or branch pipes II. The Ithermalrelief valves are then screwed or otherwise secured to suitable pipe connections 2| connected to the T-connection 20 whereby said relief valves are positioned adjacent the ceiling and in communication with the piping of the fire extinguishing system. f

Referring in detail to Figures 2 and 3, 22 indicates an annular uid chamber having a base 23 screwed therein vand an upper wall 24 also screwed therein as illustrated. The base 23 is provided with a downwardly depending pipe receiving member or extension 24' detachably receiving the screw-threaded end of pipe connection 2I. Said base 23 is also provided with an `upwardly extended inlet or stand pipe 25 extending within the chamber 22 and having a drain opening 26 therein. An` annular ange or I rib 26 preferably forms an integral part of said .base and -receives a spherical and movable valve closure member 21 of buoyant material so-that it will float in a liquid. The rib or iiange 26 provides between the wall of chamber 22 and stand .pipe 25 avball-race for the spherical valve member 21. Said rib is also provided with a plurality of openings 2liA extending therethrough land through sediment and water may be drained to and. through the drain opening 26.

The upper wall 24 of the fluid chamber is kspecially recessed to form a valve-receiving pocket as at 28 preferably of the specific configuration shown and provided with an upper flattened wall Aand an annular wall merging therewith whose diameter is of a size permitting `it vto snugly receive the spherical valve member 21. An opening 29 communicates with said recess 28 and is normally closed at its outlet side -by a removable cap and may be closed at its -inlet side by the spherical valve member 21.

The inlet pipe 25 is provided with an L-shaped deflector pin 3I, one leg of which is fastened to head led of even date herewith. Said sprinkler head portion is provided with an air chamber 25 having a lower wall or base 26" provided with an opening 21 therein and centrally thereof and a dome-shaped wall 28, the lower flanged edge of which is vsecured to the base 26 by a corresponding flange on the edge of said base. A flexible .diaphragm 29 is positioned beneath said base 26 and its annular edge is fastened intermediate said base and the annular flange 30 of a supporting member 3| provided with an opening 32 preferably in vertical alignment withl the opening 21 inthe base 26". 'I'he chamber 25 is connected to the upper wall 24 by upwardly and outwardly flaring arms or supports 33 and the interior mechanism is preferably` protected from dust and exposure by an annular cover 34 which is removably mounted in position by frictional engagement -of the lower peripheral flanged edge thereof with said upper wall 24.4

A spring metallic strip constituting a co-operating detent member is indicated at 35. One end thereof is secured to the supporting member 3|' and said strip carries a pin 32 engaging the underside of the diaphragm 29 or in position to be engaged thereby. A stop 33 is also carried by said strip to engage the supporting member 3l and limit the movement of the strip toward the diaphragm 29'.

A strut support -is -indicated at 34 and is positioned centrally of the structure and is preferably fastened thereto by arms 35 secured to -the upper wall 24. Said strut support is provided with a central screw-threaded opening receiving a screw-threaded nut or plug 36 as shown. A detent roller is indicated at l31. Its ends are journaled in bearings 38 which may be fastened tothe underside of supporting member 3|' and it is provided with a flattened portion or a flat side or recessed portion 39 and with a detent lug 4I normally engaged by the edge of the free end of the spring co-operating member 35. It is also provided with a stop 40' for engagement with memberl to limit the degree of rotation thereof.

The strut mechanismcomprises a main strut member 4I normally engaging the top of the cap 30 to hold it on its seat. The upper end of said strut engages the angled portion of a second strut member 42 and the upper end of strut member 42 engages the plug ory nut 36 While its lower end engages within an offset portion of a vertically extending strut 43 -whose lower end engages a lug 44 while its upper end engages the kvhigh or rounded portion of the roller detent 31. When the strut mechanism is set" and in operative position, as shownv in Fig. 2, the members thereof are collapsibly held in this position by the tightening of the nut `or plug 36 within the strut support 34.

Should a fire occur resulting in a sudden rateof-rise 'of temperature, the air in chamber 25' heats andv expands very rapidly and such expanded air flows through the opening 21 and exerts downward pressure against the diaphragm 29. This acts to press the pin 32 downwardly against the spring strip 3l and thereby release the free end of said spring strip from its engagement with the detent lug 40 on roller detent 31 and thus permit a spring which is fastened to said detent roller and to any xed portion of the structure, such as one of the arms 33, to be brought into action to partially rotate the roller in its bearings and release the upper end of strut member 43 from its engagement with the high or rounded portion of the detent roller and permit said upper end to pass or slide through the recessed portions 39 of said roller.

The above action leaves the strut member 49 unsupported at its upper end and in consequence the entire strut mechanism comprising strut members 4l, 42 and 4 3 collapses and the cap 30 thereupon is automatically removed from its seat by the pressure of the compressed air 4in chamber 22 and in the system which then discharges through the opening 29 to the outside atmosphere.

It is preferred to provide the lower wall 26 of chamber 25' with a breather 46 having an oriflce or opening 41 extending vertically therethrough which communicates with said chamber and with the outside atmosphere and which acts to equalize the air pressure on the upper and lower faces of the diaphragm 29. This breather compensates for any normal rise in temperature, due to weather or other conditions, which would result in a gradual increase of air pressure in the chamber 25 permitting it to escape through the orifice 4l. This orifice, however, is insuicient in size to accommodate the release of any abnormal expansion of air in chamber 25 due to a sudden rate-of-rise in temperature, as from a. fire, and such expanded air must therefore necessarily flow through opening 2l and exert pressure against diaphragm 29 to ex the same and actuate the sprinkler head mechanism in the manner described. The actuation of said mechanism is very rapid because of the rapidity with which the detent spring-controlled roller 31 functions when released.

After release of the cap 30 from its seat following the actuation of the sprinkler head mechanism, the compressed air in the fire extinguishing system rushes from the uid chamber 22 and through the opening 29 thus permitting the main Valve I5 to automatically open as it then is released from air pressure. This allows the eX- tinguishing iiuid, such as water, to ilow into the system and condition it preparatory to the fusing of one or more of the sprinkler heads i3 for discharge of the fluid therefrom. After the compressed air has been discharged, water flows into the fluid chamber 22 to float the spherical valve member 2'! and raise it upwardly with the water until it becomes seated in the pocket or depression 28 to close the opening 29 andthereby prevent any unnecessary expulsion or discharge of water from the apparatus which would result in water damage to property. After the apparatus has functioned and is in condition for re-setting, water remaining in chamber 22 is drained therefrom through drain opening 26 and the spherical valve 2l again assumes the position shown in Fig. 2 and is prevented from having become seated on the end of pipe 25 by means of the deflector pin 3l as has heretofore been explained.

When the device functions from the action of heat and the compressed air rushes from the system into chamber 22 and out of opening 29, a sufficient portion thereof strikes against the upper wall of the depression 28 and by reason of the configuration of said depression, is deected thereby downwardly against the top or upper portion of spherical Valve 2. This action prevents said spherical valve from being carried upwardly in saidY chamber with the compressed air and thus obviates any possibility of said spherical valve closing the opening 29 prior to the inrush of water into chamber 22. It has been found in practice that the action of the compressed air thus deflected against the top of the spherical valve holds it down against the uprush of air escaping from chamber 22 and in addition has the eiTect of causing said valve to travel rapidly in a circular direction and in a horizontal plane on ball-race 26 until the discharge of compressed air into chamber 22 has terminated having the said valve ready to oat in `and with the rise of water in said chamber.

As an additional means of sounding an alarm I have provided the shield or casing 34 with a conventional form of whistle 43 mounted in any manner in the wall of said casing and operable by means of the compressed air discharged into the device and which finds an outlet through said whistle. I also prefer to seal the outer surface of said whistle with a paper or other frangible seal 49 which is preferably colored with a color contrasting to that of the cover 34, which seal is broken by the outrush of compressed air through the whistle 48. The purpose of the seal is to permit an inspector to be apprised as to which, if any, of the thermal relief valves has functioned, by mere visual inspection of the seals described to ascertain which ones have been broken and without the necessity of removing the shield for inspection of the interior mechanism. In some cases also I prefer to serrate the upper edge of casing 34 form it with openings 5@ to provide for the escape of compressed air should an excessive amount thereof be present.

The invention claimed is:

1. A dry-pipe sprinkler system wherein a re extinguishing iluid isnormally excluded until a lire occurs and wherein the system is lled with air under pressure, comprising in combination with a fusible sprinkler head, of means adapted. to release the air from the system and to permit the fire-extinguishing fluid to flow to the system prior to the attainment of a temperature sufficient to actuate the sprinkler head to permit it to open and discharge the extinguishing medium therefrom, said means including a walled fluid chamber having an inlet connected with the source of extinguishing fluid supply and having a valve-receiving pocket in a wall thereof and an outlet opening communicating with said pocket, a closure cap closing said outlet opening and normally subjected to the air pressure in the system, restraining means for holding the cap in closed position, means for rendering said restraining means inoperative to permit of the automatic removal cf said cap by said air pressure and a spherical buoyant valve adapted to` be received by said pocket to close said outlet opening upon the admission of the extinguishing fluid to said iluid chamber.

2'. A dry-pipe sprinkler system wherein a iire extinguishing fluid is normally excluded until a fire occurs and wherein the system is filled with air under pressure, comprising in combination with a fusible sprinkler head, of means adapted to release the air from the system and to permit the re-extinguishingfluid to flow to the system prior to the attainment of a temperature suicient to actuate the sprinkler head topermit it to 'open and discharge the extinguishing medium therefrom, a walled fluid chamber having a valve-receiving pocket in a wall thereof and an outlet opening communicating with said pocket, said means including a stand-pipe supported in the fluid chamber in alignment with said pocket and connected to the Source of extinguishing fluid, means closing said outlet opening and normally subjected to the air pressure in the system, restraining means for holding the closing means in closed position, means for rendering said restraining means inoperative to permit of the automatic opening of' said closing means by said air pressure, and a spherical buoyant valve adapted to be received by said pocket for closing said outlet opening upon the admission of the extinguishing fluid to said uid chamber,

3. A dry-pipe sprinkler system wherein a fire extinguishing fluid is normally excluded until a re occurs and wherein the system is filled with air under pressure, comprising in combination with a fusible sprinkler head, of means adapted to release the air from the system and to permit the fire-extinguishing fluid to flow to the system prior to the attainment of atemperature suflicient to actuate the sprinkler head to permit it to open and discharge the extinguishing medium therefrom, said means including a fiuid chamber comprising an annular wall and a base and upper wall secured thereto, said upper wall'being provided with a valve-receiving pocket and an outlet opening communicating therewith, means normally closing said outlet opening and normally subjected to the air pressure in the system, restraining means for holding the closing means in closed position, means for rendering said restraining means inoperative to permit of the automatic opening of said closing means by said air pressure, a stand-pipe supported in the Abase of said chamber in alignment with said valve-receiving pocket, an annular rib on said base providing a ball-race with the Wall of said stand-pipe and a spherical buoyant valve normally engaging said ball-race and adapted for reception by said pocket for closing said outlet opening.

4. A dry-pipe sprinkler system wherein a fire extinguishing fluid is .normally excluded until a fire occurs and wherein the system is filled with air under pressure, comprising in combination with a fusible sprinkler head, of means adapted to release the air from the system and to permit the nre-extinguishing fluid to flow to the system prior to the attainment of a temperature sufficient to actuate the sprinkler head to permit it to open and discharge the extinguishing medium therefrom, said means including an annular fluid chamber provided with a valve-receiving pocket and an outlet opening communicating therewith, a closure for said outlet opening and normally subjected to the air pressure in the system, restraining means for holding the closure in closed position, means for rendering said restraining means inoperative to permit of the automatic opening of said closure by said air pressure, a stand-pipe mounted in said chamber in alignment with said pocket and provided with a drain opening therein', a spherical buoyant valve in said chamber for reception by said pocket to close said outlet opening and means carried by said stand-pipe to prevent said spherical valve from becoming seated thereon.

5. A dry-pipe sprinkler system wherein a fire extinguishing fluid is normally excluded until a re occurs'and wherein'the system Vis fllle'd'with air under pressure, comprising in combination with a fusible sprinkler head, of means adapted to release the air from the system and to permit the fire-extinguishing fluid to flow to thesystem prior to the attainment vof a temperature sufficient to actuate the sprinkler head to permit it to open and discharge the extinguishing medium therefrom, said means including a thermal device responsive to an abnormal rate-of-rise of temperature and comprising an air chamber, a flexible diaphragm in association therewith, a support having an opening therein for communication with the source of extinguishing fluid supply, a closure normally closing said opening, means connecting said air chamber and said support, mechanism connecting said diaphragm and said closure for normally retaining said closure in closed position, a spring-actuated detent for operating said mechanism to release said closure upon movement of said diaphragm, a removable shield covering said mechanism, a whistle carried by said shield for actuation by the compressed air in the system after the removal of said cap and a valve for automatically closing said opening by the flow of the re extinguishing fluid into the system.

6. A dry-pipe sprinkler system wherein a fire extinguishing fluid is normally excluded until a fire occurs and wherein the system is lled with air under pressure, comprising in combination with a fusible sprinkler head, of -means adapted to release the air from the Asystem and to permit the nre-extinguishing fluid to ow to the system prior to the attainment of a temperature suiiicient to actuate the sprinkler head to permit it to open and discharge the extinguishing medium therefrom, said means including a thermal device responsive to an abnormal rate-of-rise of temperature and comprising an air chamber, a flexible diaphragm in association therewith, a support having a valve-receiving pocket therein and an opening communicating with said pocket, a closure normally closing said opening, mechanism connecting said diaphragm and said closure for'normally retaining said closure in closed position, a spring-actuated detent for operating said mechanism to release said closure upon movement of said diaphragm, a uid chamber communicating with the source of extinguishing fluid and with said Valve-receiving pocket and opening and a spherical buoyant valve member within said chamber adapted to` be received by said pocket for closing said opening. 7. A dry-pipe sprinkler system wherein a fir extinguishing fluid is normally excluded until a fire occurs and wherein the system is filled with air under pressure, comprising in combination with a fusible sprinkler head, of means adapted to release the air from the system and to permit the fire-extinguishing fluid to flow to the system prior to the attainment of a temperature sufcient to actuate the sprinkler head to permit it to open and discharge the extinguishing medium therefrom, said means including a fluid chamber comprising an annular wall and a base and upper wall secured thereto, said upper wall being provided with a valve-receiving pocket and an outlet opening communicating therewith, means closing said outlet opening and normally subjected to the air pressure in the system, restraining means for holding the closing means in closed position, means for'rendering said restraining means 'inoperative to permit of the automatic opening of Said closing means by said air pressure, a stand-pipe supported in the base of said chamber and provided with a drain opening communicating with the system and an annular rib on said base provided with an opening cemmunicating with said drain opening and a buoyant valve normally engagingv said rib and adapted to be received by said pocket for closing said outlet opening.

8. A dry-pipe sprinkler system wherein a re extinguishing fluid is normally excluded until a re occurs and wherein the system is filled with air under pressure, comprising in combination with a fusible sprinkler head, of means adapted to release the air from the system and to permit the fire-extinguishing fluid to flow to the system prior to the attainment of a temperature suicient to actuate the sprinkler head to permit it to open and discharge the extinguishing medium therefrom, said means including a thermal device responsive to an abnormal rate-of-rise of temperature and comprising an air chamber, a ilexible diaphragm in association therewith, a support having an opening therein for communication with the source of extinguishing fluid supply, a closure normally closing said opening, means connecting said air chamber and said support, mechanism connecting said diaphragm and said closure for normally retaining said closure in closed position, a spring-actuated detent for operating said mechanism to release said closure upon movement of said diaphragm, a removable shield covering said mechanism, an audible signal visibly mounted in a wall of said shield for actuation by the pressure of the compressed air in the system after the removal of the cap and a buoyant valve for automatically closing said opening upon the flow of the re extinguishing iiuid into the system.

9. A dry-pipe sprinkler system wherein a fire extinguishing fluid is normally excluded until a fire occurs and wherein the system is lled with air under pressure, comprising in combination with a fusible sprinkler head, of means adapted to release the air from the system and to permit the fire-extinguishing uid to ow thereto prior to the attainment of a temperature sucient to open the sprinkler head, said means including a walled iluid chamber having an inlet connected with the source of extinguishing fluid supply and having a valve-receiving pocket formed'in a wall thereof in vertical alignment with said inlet and having a flattened upper wall forming a part of said fluid chamber and an outlet opening communicating with said pocket, means for closing said outlet opening and normally subjected to the air -pressure in the system, restraining means for holding said closing means in closed position, means for rendering said restraining means inoperative to permit of the automatic opening of said closing means by said air pressure, and a spherical buoyant valve adapted to be retained in inoperative position in said chamber by the force of the compressed air deflected downwardly by the flattened wall of said pocket against said valve and adapted to' ber carried by the extinguishing fluid to operative position within said pocket to close said outlet opening upon a cessation of the discharge of compressed air through said inlet and the consequent flow of the extinguishing medium within said chamber.

10. A dry-pipe sprinkler system wherein. a re extinguishing fluid is normally excluded until a re occurs and wherein the system is filled with air under pressure, comprising in combination with a fusible sprinkler head, of means adapted to release the air from the system and to permit the fire-extinguishing fluid to ow thereto prior to the attainment of a temperature sufficient to open the sprinkler head, said means including a fluid chamber comprising an annular wall and an upper wall and a lower wall connected thereto, said upper wall being provided with a pocket therein having an upper flattened wall and an annular Wall merging therewith and having an outlet opening communicating therewith, means closing said outlet opening and normally subjected to the air pressure in the system, restraining means for holding said closing means in closed position, means for rendering said restraining means inoperative to permit of the automatic opening of said closing means by said air pressure, an inlet pipe `connected with the system and mounted in the lower wall of the chamber and extending within the chamber in alignment with the upper iiattened wall of said pocket and a spherical buoyant valve normally lying in inoperative position in engagement with the lower wall of the chamber and intermediate its annular wall and said inlet pipe and adapted to be retained in such inoperative position by the force of the compressed air discharged from said inlet pipe and vdeflected downwardly by the upper attened wall of said pocket and against said spherical valve and adapted to be carried by the extinguishing fluid to operative position within said pocket to close said outlet opening upon cessation of the discharge of compressed air through said inlet pipe and the consequent flow of the extinguishing medium within said chamber.

11. A dry-pipe sprinkler system wherein a re extinguishing iiuid is normally excluded until a flre occurs and wherein the system is filled with air under pressure, comprising in combination with a fusible sprinkler head, of means adapted to release the air from the system and to permit the nre-extinguishing f'luid toflow thereto prior to the lattainment of a temperature sufficient to open the sprinkler head, said means including a chamber having an inlet connected to the source of extinguishing fluid supply and also having an outlet, means closing said outlet and normally subjected to the air pressure in the system, restraining means for holding said closing means in closed position, means for rendering said re- Y straining means inoperative to permit of the automatic opening of said closing means by said air pressure, deflecting means associated with said chamber, and a buoyant element normally lying in inoperative position in said chamber and adapted to be retained in such inoperative position by the force of the compressed air discharged from said inlet against said deflecting means and deflected thereby against said element, said element being adapted to be carried by the extinguishing fluid to operative position to rclose said outlet upon cessation of the discharge of compressed air through said inlet and the consequent flow of extinguishing fluid therethrough and to said chamber.

ERNEST A; LOWE.

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