US3595318A

US3595318A - Accelerator for fire extinguisher system

Info

Publication number: US3595318A
Application number: US846814A
Authority: US
Inventors: Philip H Merdinyan
Original assignee: Grinnell Corp
Current assignee: Grinnell Corp
Priority date: 1969-08-01
Filing date: 1969-08-01
Publication date: 1971-07-27
Anticipated expiration: 1988-07-27
Also published as: GB1320364A; BE754214A; AT322987B; FR2057889A5; NL7011363A; DE2037405A1; CA926723A; AU1817870A

Abstract

A dry pipe valve accelerator device for a sprinkler system wherein a portion of the accelerator system sensitive to the opening of one or more of the sprinkler valves is isolated from the water supply. In particular, the air pressure in the sprinkler system is continuously monitored by a differential pressure chamber such that a recognition of lowering of air pressure in the piping causes the actuation of a differential pressure responsive valve actuator which in turn permits the rapid opening of the control valve of the sprinkler system.

Description

United States Patent 1,464,614 8/1923 Nacey et a1.

Inventor Philip H. Merdinyan East Greenwich, R.l.

Appl. No. 846,8

Filed Aug. 1, I969 Patented July 27, 1971 Assignee Grinnell Corporation Providence, R.l.

ACCELERATOR FOR FIRE EXTINGUISHER SYSTEM 13 Claims, 4 Drawing Figs.

U.S.Cl 169/17, 169/20 Int. Cl ..A62c 35/00 Field of Search 169/17, 20. 19, 21; 251/62, 63.4, 229

References Cited UNITED STATES PATENTS 1,958,287 5/1934 Tyden 169/17 2,731,091 1/1956 Robbins 169/17 2,969,842 1/1961 Ault 169/17 Primary Examiner- Richard A. Schacher Assistant Examiner-Thomas C. Culp, Jr. Attorney-41. Edward Foerch ABSTRACT: A dry pipe valve accelerator device for a sprinkler system wherein a portion of the accelerator system sensi- -tive to the opening of one or more of the sprinkler valves is isolated from the water supply. In particular, the air pressure in the sprinkler system is continuously monitored by a differential pressure chamber such that a recognition of lowering of air pressure in the piping causes the actuation of a dif-- ferential pressure responsive valve actuator which in turn permits the rapid opening of the control valve of the sprinkler system.

AccELERA'roRroR rum EXTINCUISHER SYSTEM BACKGROUND OFTIIE INVENTION pressed air into the ,distribution piping. When undue heat opens one or more of the automatic sprinklers in a conventional fashion, the air pressure in the piping is altered (reduced), causing a control valve to open and pass water into the distribution piping from the water supply main. Generally in order to operate the control valve more rapidly, that is, where there is only a small pressure drop (i.e. when only one sprinkler valve opens), accelerator devices are included as a part of the automatic sprinkler system.

Such accelerator devices have in the past usually comprised an elastomer diaphragm having a piston position for movement therewith to open through a suitable linkage, a valve which in turn opens the-main control valve to permit water to flow into the sprinkler distribution pipes. In accelerator devices using the diaphragm to sense a change in air presure in the distribution piping, a portion of the water passing through the control valve also passes into the accelerator on one side of the diaphragm (see FIG. 1 prior art). Periodic required testing of such accelerators has generally resulted in deterioration of the diaphragm causing the sameto stick in use, or to lose its sensitivity to detect a small change in air pressureln addition, since the water is generally dirty, that is carrying a good deal of rust from the pipes, this has generally causedfclo'gging of the orifice for equalizing air pressure on both sides of the diaphragm thereby effecting the operation of the accelerator. v

It has been found that the clogging of the orifice has been one of the major causes'of faulty accelerator operation, and thus there has developed a great need to overcome thc'excessive maintenance required to insureproper accelerator operation.

SUMMARY AND OBJECTS OF THE INVENTION means having a medium therein, saidmedium of said control means being isolated from the tire extinguishing medium controlled by said accelerator such that there is no intermingling of the fire extinguishing medium and the control medium.

Accordingly, the principal object of the present invention is to provide A a new,- improved, practical and commercially satisfactory accelerator device for an automatic fire sprinkler system of the dry pipe character.

Another object of the invention is to provide a new and improved accelerator wherein thecontrol means therefore does not come in contact with the tire extinguishing medium.

A further object of the present invention is to provide a new and improved accelerator for a dry pipe sprinkler system which avoids the disadvantages and deficiencies of the prior art diaphragm accelerator systems.

Another object of this invention is to provide a new and improved accelerator system wherein the pressure sensitive portion of thesystem is isolated from the waterpassing into the distribution piping.

Further objects, advantages and features of the invention will become apparent from the following detailed description v of the preferred specific embodiments illustrated in the drawings.

DESCRIPTIGN OF THE DRAWINGS art diaphragm-type of an accelerator system for a dry pipe type of sprinkler system;

FIG. 2 represents a side elevation, shownpartly in vertical section, of the preferred form of accelerator device in accordance with the invention and wherein a portion of the distribution piping is also shown; V 7

FIG. 3 represents a diagrammatic illustration of another form according to the invention wherein only a portion of the accelerator system is shown, and

FIG. 4 represents a diagrammatic illustration of yet another embodiment according to the invention wherein water under pressure rather than air is used as a feedback signal to accelerate the action of the control valve.

DESCRIPTION OF THE INVENTION Reference should now be had to FIG. 1 which diagrammatically illustrates an accelerator device according to the prior art and which is shown connected to the main valve of the sprinkler system.

The main valve is shown at 10 and includes means for connecting a water main pipe 11 thereto and means for coupling the sprinklersystem distribution piping l2 thereto. Within the valve 10 there is shown two clappers, a larger one at 13 and a smaller one 14, positioned to prevent water from the main pipe 11 from passing therethrough. The larger clapper 13 is held down'by the air pressure in the distribution piping l2 and maintains the smaller clapper l4 closed. Coupled to the valve 10 is an accelerator 20 of the prior art, which includes first and

second chambers

21 and 22 separated by a diaphragm 23 having a diaphragm rod 24 supported by parts (not shown) to move therewith. A small orifice 25 is provided to allow the air pressure on both sides of the diaphragm to equalize. The chamber 21 "is coupled on one side by piping shown at 27 to the main valve so that the pressure in the

chambers

21 and 22 are both charged with air at the same pressure of the air (normally 40 p.s.i.) in the distribution piping 12. At 28, there is provided piping for connecting the chamber 29 (between the two clappers of the main valve 10) to the accelerator chamber 21. The piping 28 is normally closed by a ball valve arrangement shown at 30. A drip check valve 26 drains the chamber 29 so that the air in the chamber 29 is normally at atmospheric pressure.

Upon the opening of one or more of the sprinkler system antomatic sprinklers (not shown), a sudden drop of pressure occurs in chamber 21. Because of the restricted flow through orifice 25, the pressure in the chamber 22 will not follow the sudden drop in pressure in chamber 21. The higher pressure in the chamber 22 causes the diaphragm 23 to move the rod 24 ina direction to the left in FIG. 1) to upset the ball valve 30 so as to permitair under system pressure to flow into the chamber 29 with sufficient volume and force to close the drain check. valve and to equalize the air pressure on both sides of clapper 13.

At this point the water pressure of the water in the main 11 causes the clappers l3 and 14 to move upwardlyand open to permit water to flow through the valve 10 into the distribution piping 12. As may be seen the water in the valve will also simultaneously fill up chamber 21 of the accelerator and cause deterioration of the exposed diaphragm, as previously mentioned and in addition cause clogging of the orifice 25. Thus, each time an accelerator is used for testing purposes, the accelerator must be cleaned out and particularly the orifice must be cleaned to insure that it is fully opened.

Reference should now be had to FIG. 2 which shows par tially in section, the preferred embodiment according to this invention coupled to control or main dry pipe valve shown at 40. At 41 there is shown a water supply main coupled to the valve 40. The valve 40 is essentially of the differential type which is adapted to function on relief of the ordinarily maintained pressure in the distribution piping shown at 42. The valve has a clapper or valve 43 held to its seat against any pressure of water in the main 41 by means ofa clapper or valve 44 hinged at 45 and suitably connected to the clapper 43 so that pressure of the fluid (i.e. gas (air) is the chamber 46A will normally keep the water clapper 43 on its seat. As shown, the clapper 44 has ordinarily a larger surface area exposed to pressure of the air than the pressure area of 44 exposed to water, thus insuring the retention of valve 43 on its seat under the normal conditions of pressures in the

pipes

41 and 42. The distribution pipe ofthe piping system is connected to the usual pipes having outlets thermally controlled, one of such outlets being indicated at 47 as a usual sprinkler of a typical form wherein an outlet valve is normally held closed but is adapted to open when released by the action of heat thereon.

The functioning of the valve 40 in the usual way of the dry pipe system occurs when an outlet of the system is opened by the action of heat thus relieving the air pressure on the clapper 44 and permitting any superior water pressure then existing on clapper 43 to open the same and throw back the clapper 44 so that the fire extinguisher medium may pass freely from pipe 41 to 42.

In order to accelerate the opening of the valve 40, there is provided a new and improved accelerator device 49 which includes a chamber 50 having a valve arrangement shown at 51. The valve arrangement may conveniently comprisea ball stem 52 supported in a valve cage 53 which is pivoted at 54. The valve cage 53 is adapted to normally position the ball stem 52 against a valve seat 55 in order to prevent air present in the chamber 50 from passing through pipe A into the chamber 468 between the two

clappers

43 and 44 of the main dry pipe valve. The cage 53 is maintained in position by a weight 56 shown pivoted at 57, which bears thereon. Air under pressure is provided to the chamber 50 by way of a pipe B coupled to the chamber 46A. Upon rotation of the weight 56 about its pivot 57, the member 58 coupled to the weight 56 kicks the ball stem 52 and cage 53 off its seat 55 and permits air under pressure to flow through pipe A to tend to equalize the air pressure on both sides of the clapper 44, Le. to disturb the balance of the gaseous pressure in the main dry valve, which then permits clapper 43 to open under the pressure of the water against it.

In order to sense the air pressure in the distribution piping 42 there is provided a branch pipe C coupled to pipe B and which in turn is coupled to one side of a differential pressure chamber shown at 60, which senses a change in pressure ofthe air in the distribution piping. The chamber includes a piston 61 resiliently biased by a spring 62 positioned in a chamber portion 608. On the spring 62 side of the piston 61, oil or hydraulic fluid is provided by a pipe network shown generally at 64 which is filled through plugs 64A. The chamber 60A is coupled via the pipe network 64 through a restriction 65 to an accumulator shown at 70. The accumulator comprises a piston 71 which is adapted to move within the accumulator between a lower portion 72A (air at atmospheric pressure) and an upper portion 72B (hydraulic fluid filled). The piston 71 is resiliently biased against the hydraulic fluid in the upper portion 728 by a spring 73. Air is permitted to evacuate from the lower portion 72A via the orifice 74. The accumulator 70 is itself coupled through the pipe network 64 to one side of a differential pipe valve actuator shown at 80. The actuator comprises a piston 81 slideable within a chamber 82. Hydraulic fluid is provided to the other side of the piston 81 via the portion of the piping 64 coupled to the differential chamber 60A. Partially positioned within the chamber 82 and slidably movable therein is a rod 83 adapted to be moved to engage the weight 56 in chamber 58 in order to topple the same to open the valve arrangement ln this configuration, the

chambers

82 and 50 are separated by appropriate sealing means (in this case an O-ring about the rod 83) to prevent the passage of fluid (either air or fire extinguishing medium) from the chamber 50 into the chamber 82 in order to prevent the comingling of the fluids in both

chambers

82 and 50.

The device disclosed above acts as follows: the system (distribution piping) air pressure is continuously monitored or sensed by the differential chamber where it is balanced by the spring 62 and the pressure of the hydraulic fluid therein. Upon the opening ofone of the sprinklers 47, the reduction in the distribution system air pressure causes piston 61 to fall, thereby reducing the hydraulic fluid pressure on the opposite side of the piston 61 and the pressure of the fluid to the left of piston 81. Since the fluid on the accumulator side of the restrictor bleeds slowly through the restrictor, the pressure of the hydraulic fluid therein causes the piston 8] to move towards the left and causes the rod 83 to slidably move and engage the weight 56, toppling the same and causing the ball valve arrangement 51 to open.

The pressure difference on either side of clapper 44 is thereby reduced and clapper 43 opens, as previously described to permit the flow of water into the distribution piping 43 from the main 4].

Referring now to FIG. 3, there is diagrammatically shown an alternate embodiment according to this invention. ln this embodiment instead of applying the system pressure on both sides of clapper 44, in the event one or more of the sprinklers 47 open, the air pressure on both sides of clapper 44 is equalized to atmospheric pressure. This is accomplished by venting pipe A to the atmosphere as shown. The chamber 46B between

clappers

43 and 44 is vented to atmosphere through the drain check valve 89 in a conventional manner and would remain open until water enters the system. Thus when one or more of the sprinklers 47 open, the valve arrangement 51 will open as described with regard to the embodiment of FIG. 5, the air pressure on both sides of clapper 44 will be equalized, and the

clappers

43 and 44 will open due to the water pressure in the main 4].

In FIG. 4 there is shown another embodiment in diagrammatic form according to this invention. The parts are as previously described with regard to FIGS. 2 and 3 except that in the event that one of the heads 47 opens, water under pressure is forced into the chamber 46B between the two clappers to permit both clappers to open. This is accomplished by coupling pipe A directly to the water main 4] and adding a pipe D interconnecting the chamber 468 between two

clappers

43 and 44 to the chamber 50. In this embodiment the system air pressure is set so that the two clappers will open against the system air pressure in the event that water under pressure from the main is forced into the chamber 46B between the two

clappers

43 and 44 via pipe A, chamber 50, opened valve valve 51 and pipe D.

It is apparent from the above description that with this invention there is prevented a comingling of fire extinguishing fluid and the control media. This not only reduces maintenance as a result of the required periodic testing of such systems but also insures the continued sensitivity of said accelerator because the orifice or restriction 65 is isolated from the rust and other contaminants in the fire extinguishing mediurn.

This completes the description of the preferred embodiments of this invention. It should be understood that various modifications and alterations may be made without departing from the spirit and scope of this invention. For example, the valve arrangement 51 may comprise a faucet-type valve; the accumulator may comprise a blatter-type accumulator, and the elements of the accelerator may be combined as a single device with the piping 64 having the shape of fluid passages formed in a cast housing of the device. It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention which, as a matter oflanguage, might be said to fall therebetween.

What l claim is:

1. An accelerator for use in a dry pipe fire extinguisher system, having main valve controlling the admission of a fire extinguishing medium to the system and normally held closed against the pressure of a supply of said medium by the normal pressure of the gas in the system, sensing means including a fluid medium responsive to a change in the pressure of the gas in the system, and actuating means responsive to said fluid medium for disturbing the balance of the gaseous pressure in said main valve to permit the same to open, said actuating means comprises first and second chambers, a control valve in said first chamber; a piston in said second chamber responsive to said fluid medium, control valve opening means in said first chamber for opening said control valve, and linkage means positioned between said first and second chambers and responsive to said piston for acting on said control valve opening means.

2. An accelerator according to claim 1 in which said sensing means includes a differential pressure chamber responsive to pressure of the gas in the system, fluid passages connecting said differential pressure chamber to said second chamber at point on one side of said piston and also to an accumulator through an orifice, and a fluid passage connecting said accumulator to the second chamber at a point on the opposite side of the piston, said fluid medium being present in said fluid passages, and said accumulator and said differential pressure chambers.

3 An accelerator according to claim 1 in which said linkage means comprises a rod movable within both of said first and second chambers.

4, An accelerator according to claim 2 in which said linkage means comprises a rod slidably movable within both of said first and second chambers.

5. An automatic fire extinguisher system including a dry pipe valve coupling a water main to the distribution piping of a sprinkler system, said dry pipe valve having a first clapper and a second clapper, said first clapper normally maintaining by linkage means said second clapper in a closed position, a dry pipe valve chamber being formed between said first and second clappers, an accelerator responsive to the pressure of the air in said distribution piping, said accelerator comprising a chamber having an inlet port and an outlet port, said inlet port coupled to the water main, said outlet port coupled to dry pipe valve chamber, and valve means for controlling the flow of fluid from said water main to said dry pipe valve chamber, said valve means including means responsive to a change in the pressure of the air in said distribution piping.

6. An accelerator for use in a dry pipe fire extinguisher system having a main valve controlling the admission of a fire extinguishing medium to the system and normally held closed against the pressure of a supply of said medium by the normal pressure of the gas in the system, actuating means for disturbing the balance of the gaseous pressure in said main valve to permit the same to open, control means to control the operation of said actuating means means responsive to a change in pressure in said system to operate said control means, said control means being located so that said fire extinguishing medium does not come in contact therewith.

7. An accelerator device for a dry pipe valve interconnect ing a main to distribution piping comprising a first chamber having an inlet port and an outlet port, valve means in said first chamber for preventing fluid in said first chamber from entering said outlet port, a second chamber, first means positioned in said second chamber and extending into said first to open said valve means of said first chamber, actuating means in said second chamber to actuate said first means to cause said valve means in said first chamber to open, and second means having fluid therein which is responsive to the pressure of the air in the distribution piping for actuating said actuating means.

18. A method of controlling a dry pipe valve for coupling a water main to the distribution piping of a sprinkler system comprising (1) sensing the pressure of the air in the distribution piping of said sprinkler system, (2) responsive to a predetermined change of said sensed air pressure, moving a fluid in a separate, closed fluid system includin' a iston to establish a pressure differential on said piston, ant (3 moving a control means outside of said fluid system by movement of said piston in accordance with said pressure differential to control the opening of said dry pipe valve.

9. An accelerator for use in a dry pipe fire extinguisher system, having main valve controlling the admission of a fire extinguishing medium to the system and normally held closed against the pressure of a supply of said medium by the normal pressure of the gas in the system, sensing means including a fluid medium responsive to a change in the pressure of the gas in the system, said sensing means including separating means positioned between said fluid medium of said sensing means and said fire extinguishing system for closing said sensing means to intermingling of said fire extinguishing medium with the medium of said sensing means, and actuating means responsive to said fluid medium for disturbing the balance of the gaseous pressure in said main valve to permit the same to open.

10. An accelerator for a dry pipe fire extinguisher system having a main valve controlling the flow ofa fire extinguishing fluid into the system and held closed by a gas pressure in said system, comprising control means for disturbing the balance of pressures on said main valve to cause said main valve to open, a closed fluid conduit means including a fluid moving means having a movable surface face for sensing the pressure of said gas in said fire extinguisher system and for moving fluid in said fluid conduit system in accordance with said sensed gas pressure, piston means operatively connected to said control means, said fluid conduit means further including means for establishing a fluid pressure differential on opposed surfaces of said piston means responsive to change in said air pressure, whereby said pressure differential moves said piston to actuate said control device when said air pressure decreases at a rate which is greater than a predetermined rate.

11. An accelerator according to claim 10, in which said sensing means comprises a cylinder and piston, one surface of said piston communicating with said gas pressure in said fire extinguisher system and an opposing surface of said piston communicating with fluid in said closed fluid system.

12. An accelerator according to claim 11, in which said sensing piston is resiliently biased toward said gas pressure.

13. An accelerator according to claim 10, in which said means for establishing a pressure differential on said piston means includes an accumulator and an orifice located in said closed fluid system between said sensing means and said accumulator and between said opposed surfaces of said piston means.

Claims

2. An accelerator according to claim 1 in which said sensing means includes a differential pressure chamber responsive to pressure of the gas in the system, fluid passages connecting said differential pressure chamber to said second chamber at point on one side of said piston and also to an accumulator through an orifice, and a fluid passage connecting said accumulator to the second chamber at a point on the opposite side of the piston, said fluid medium being present in said fluid passages, and said accumulator and said differential pressure chambers. 3 An accelerator according to claim 1 in which said linkage means comprises a rod movable within both of said first and second chambers. 4, An accelerator according to claim 2 in which said linkage means comprises a rod slidably movable within both of said first and second chambers.

6. An accelerator for use in a dry pipe fire extinguisher system having a main valve controlling the admission of a fire extinguishing medium to the system and normally held closed against the pressure of a supply of said medium by the normal pressure of the gas in the system, actuating means for disturbing the balance of the gaseous pressure in said main valve to permit the same to open, control means to control the operation of said actuating means, means responsive to a change in pressure in said system to operate said control means, said control means being located so that said fire extinguishing medium does not come in contact therewith.

7. An accelerator device for a dry pipe valve interconnecting a main to distribution piping comprising a first chamber having an inlet port and an outlet port, valve means in said first chamber for preventing fluid in said first chamber from entering said outlet port, a second chamber, first means positioned in said second chamber and extending into said first to open said valve means of said first chamber, actuating means in said second chamber to actuate said first means to cause said valve means in said first chamber to open, and second means having fluid therein which is responsive to the pressure of the air in the distribution piping for actuating said actuating means.

10. An accelerator for a dry pipe fire extinguisher system having a main valve controlling the flow of a fire extinguishing fluid into the system and held closed by a gas pressure in said system, comprising control means for disturbing the balance of pressures on said main valve to cause said main valve to open, a closed fluid conduit means including a fluid moving means having a movable surface face for sensing the pressure of said gas in said fire extinguisher system and for moving fluid in said fluid conduit system in accordance with said sensed gas pressure, piston means operatively connected to said control means, said fluid conduit means further including means for establishing a fluid pressure differential on opposed surfaces of said piston means responsive to change in said air pressure, whereby said pressure differential moves said piston to actuate said control device when said air pressure decreases at a rate which is greater than a predetermined rate.

12. An accelerator according to claim 11, in which said sensing piston is resiliently biased toward said gas pressure. 13. An accelerator according to claim 10, in which said means for establishing a pressure differential on said piston means includes an accumulator and an orifice located in said closed fluid system between said sensing means and said accumulator and between said opposed surfaces of said piston means.

18. A method of controlling a dry pipe valve for coupling a water main to the distribution piping of a sprinkler system comprising (1) sensing the pressure of the air in the distribution piping of said sprinkler system, (2) responsive to a predetermined change of said sensed air pressure, moving a fluid in a separate, closed fluid system including a piston to establish a pressure differential on said piston, and (3) moving a control means outside of said fluid system by movement of said piston in accordance with said pressure differential to control the opening of said dry pipe valve.