US2485091A - Deluge valve - Google Patents

Description

Oct. 18, 1949; H. G. FREEMAN 2,485,091

DELUGE VALVE Filed Jan. 8, 1945 Fig.1 v

62 T 10 TO DRAIN v I [A Q a n. 34 ll/ 36 76 Filii 32 30 38 N I m Inventor Patented Oct. 18, 1949 DELUGE VALVE Howard G. Freeman, Worcester,

Mass, assignmto Rockwood; Sprinkler Company, Worcester, Mass, a corporation of Massachusetts Application January 8, 1945, Serial N 0. 571,734

6 Claims. 1

The present invention relates to fire extinguishing apparatus, and more particularly to an automatic release or deluge valve for use with automatic sprinkler systems of the so-called preaction and deluge types.

Numerous arrangements have hitherto been proposed by which the pipes of a sprinkler system may be kept free of water until the occurrence of fire, while permitting the system to go into operation rapidly when the need arises. In a system of this type, the admission of water to the system is under the control of a master valve, termed a deluge valve, which is constructed to permit substantially instantaneous opening to full capacity to admit water from the supply main to the distributing pipes of the sprinkler system when operation is called for.

To hold the deluge valve closed against the pressure in the supply main and still permit re lease by quick acting means operating at a low energy level, various holding arrangements have been devised. Some valves employ positive latching arrangements, toggle linkages, and the like, but these generally require a somewhat higher actuating force than can be directly supplied by the fire detecting means, and hence depend for release on the energy supplied by some additional source, as by a falling Weight.

In place of the mechanically held valve, it has been proposed to use the pressure of the water in the supply main, acting on a second valve of greater area than the primary valve controlling the admission of water to the system, to hold said latter valve closed. Such an arrangement makes use of differential pressure from a single source and hence, at least in theory, holds the valve closed, even though the water pressure in the supply main varies appreciably. The valve is actuated upon the occurrence of fire by releasing the pressure to which the second valve is exposed, which may be readily accomplished by sensitive fire-detecting means.

Automatic deluge valves operating on the differential pressure principle have not, however, proved successful and have therefore not been adopted for use. The principal fault has been a failure of the valve to remain properly closed to maintain the system in readiness for operation. The difiiculty is believed due to the effects of sudden changes or fluctuations in pressure in the supply main, particularly the violent pressure Waves or shocks commonly termed water hammer, which frequently occur when flow is abrupt- 1y stopped at some point in a water supply system operating at appreciable pressure. Such changes temporarily overcome or unbalance the difi'erential holding pressure normally available and thereby cause the valve to become unseated. Once the valve is opened, even though only partially,v the resulting pressure: drop in thesupply main so diminishes the pressure on the secondary or holding valve that the deluge valve immediately goes to fully open position.

It is therefore an object of the present invention to provide, for use in fire extinguishing systems of the dry-pipe type, an automatic deluge valve adapted to utilize the water pressure in the supply main to hold the valve closed, said valve being so constructed and arranged as to be unafiected bywater hammer or other sudden and violent pressure changes in the supply main.

This result has been-attained by the provision in. a deluge valve employing differential water pressure to hold the valve closed, or means by which, without the use of air bells and the like, sudden pressure disturbances such as water hamnier may be absorbed and neutralized, so as to enable the valve to remain seated. More specifically, means are provided for freely transmitting sudden pressure changes or waves to the holding valve, so that the pressure increase, even though of short duration, may be available at the holding valve to offset the force of said disturbance on the main valve and thereby leave the valve substantially unafiected by the hammer.

The invention is illustrated in the accompanying drawings, in which Fig. 1 is a sectional view of the valve, with associated apparatus illustrated in schematic fashion; and Fig. 2 is a detail view of the valve seat retaining ring.

The valve is adapted to be connected in accordance with conventional practice between the distributing main of the fire extinguishing system and the supply main within which Water or other fire extinguishing fluid is maintained under pressure. In order that the valve, when open, may offer minimum resistance tov the flow of water to the distributing main, the inlet and outlet passages 8 and Hi are arranged in a straight line, so that no diversion or turning of the flow is required.

The valve is normally closed by a clapper l2 which is held in contact with the valve seat l4 by the differential pressure means to be described. The valve seat I4 is formed of a resilient material such as rubber, and is of U-shaped section to permit the water pressure itself to aid in providing a tight sealing engagement with the clapper. The seat I4 is confined within an annular recess formed in a valve insert It, a fiat seatretaining ring I8 being provided to prevent the seat being dislodged by the water flow when the valve goes into action. The retaining ring is formed in three parts with two pivotal connections 20 and 22 and a disconnectible joint 24.

to permit insertion between the two walls of the U-shaped seat. Y

The clapper is held in closed position, against the pressure of the water-inthe supply main, by the action of the same water pressure on a holding clapper 30 having greater effective area than the area of the valve clapper l2. An area, ratio of approximately two to one has beenfound appropriate.

The holding clapper is arranged normally to close a passage between the holding chamber 32 and the valve outlet I0, the clapper being held against a seat 34 by the water pressure within the holding chamber. The valve clapper I2 is connected to the holding clapper 30 by an arm 36 which supports the valve clapper at approximately a right angle to the holding clapper. A pivotal connection 38 is provided between the arm and the valve clapper to permit limited movement of the latter for self-aligning with the seat, and a bearing engagement 40 is likewise provided between complementary ball and recess surfaces on arm and clapper, respectively, to aid in supporting the valve clapper against the water pressure in the main. V

The assembly of valve and holding clappers l2 and 30 is mounted for swinging movement about a pivot 42 which is positioned to permit the holding clapper, upon operation of the valve, to swing into the holding chamber and at the same time allow the valve clapper 12 to swing away from its seat to a position within the opening normally occupied by the holding clapper when the valve is closed. The valve clapper is thereby substantially removed from the line of water flow, so as not to interfere with the straight-through flow of water through the valve. As a consequence, there is no appreciable pressure drop across the valve when the system is in operation.

As a consequence of the restricted flow communication, the valve may be caused to open to admit water from the supply to the distributing pipes of the system by lowering the pressure within the holding chamber so that the total effective pressure on the holding clapper 30 becomes less than the pressure on the valve clapper l2. Such reduction of pressure permits the valve to open by direct action of the water pressure of the supply, without requiring the release of latches or other mechanical locking devices. The release of water pressure within the holding chamber may readily be accomplished automatically through the provision of conventional fire detecting means in control of a release valve of conventional construction and indicated generally at 60, connected to the holding chamber 32 by a pipe 62 and arranged to discharge, when open, through pipe 64 into a suitable drain. As only a small volume of water need be released in order to provide a substantial pressure drop,

the response may be very rapid and the releasing means may be small and therefore operative at a low energy level.

While the restricted fiow communication be tween the supply main and the holding chamber as provided by the orifice 56 is normally adequate to permit equalization of water pressure and. therefore provide a total effective pressure on the: holding clapper substantially in excess of the total pressure on the relatively smaller valve: clapper l2, under certain conditions the water" pressures may temporarily become unequal. That is, sudden changesin Water pressure, due to opening 'or closing a valve in some other part of the supply system, may not be transmitted to the holding chamber, by way of the flow orifice, with sufficient rapidity to maintain the diflferential holding pressure on the clapper 30. If the water pressure in the holding chamber drops even momentarily below. that necessary to maintain the clappers closed, the valve is likely to become tripped and to open, causing the sprinkler system to go into operation.

"To avoid this difliculty, which has heretofore constituted a serious obstacle to the use of deluge valves operating 0n the difierential-pressure principle, there is provided, between the supply main and the holding chamber of the valve, means bywhich rapid changes in pressure, including shocks such as Water hammer, may be freely transmitted to the holding chamber. In order that the equalization of pressure, upon the occurrence of pressure disturbances, may be as effective as possible, the communication provided must be relatively direct and of appreciable crosssectional area as compared with the limited flow communication provided by the orifice.

To this end, there is provided between the holding chamber 32 and the supplementary chamber 54 a flexible diaphragm 10 having one face directly exposed to the water in the holding chamber 32, while the other face is exposed to the water in the supplementary chamber 54 which is in substantially direct communication with the supply main through pipe 50. The size of this pipe and the capacity-of the filter 52 must be adequate to transmit freely to the supplementary chamber 54 such changes in pressure as may occur within the valve inlet 8 and to which the valve I2 is subjected. By way of illustration, a pipe of approximately one-third the diameter of the valve inlet has been found to transmit effectively even the most rapidly occurring changes in pressure, such as those occasioned by a water hammer.

Theflexible diaphragm thus provides a means of equalizing the water pressures on the two clappers under conditions where the flow-communicating orifice would not be effective, due to its necessarily limited capacity, if the valve is to be readily releasable by lowering the water pressure in the holding chamber. By using the diaphragm and a connecting pipe of relatively large cross-section, pressure changes tending to unseat the valve clapper l2 are effectively counteracted by corresponding pressure changes acting on the holding clapper 30. As a consequence, the valve may be relied upon to remain closed in spite of water hammers and other pressure disturbances which may occur in the supply mam.

To protect the flexible diaphragm, which may be of thin corrugated metal, against excessive displacement, the clamping rings 12 by which the diaphragm issecured across the opening between span-091 holding chamber 32 and supplementary chamber 54 may be provided with protective grids 14. Because of the relative incompressibilityof water, only a limited travel oi thediaphragm is required for transmission of substantial changes in pressure.

Since the valve is well adapted'for use in conventional systems employing well known fire detecting, valve releasing, and warning devices, such apparatus has not been shown and described, as the provision of such apparatus in association with this valve will be obvious to those skilled in the art. Thus, the valve may be provided with the usual connections for actuating a warning bell or alarm when the valve goes into operation, while an inspection plate 16 provides access for resetting the clapper after an operation of the system.

The invention thus comprises a valve, operating on the differential pressure principle, for use in fire fighting systems where the highest degree of dependability is required, not only that the valve may be released with certainty by means operating at a relatively low energy level, but also that the valve will remain closed until operation is required, without risk of being accidentally tripped because of water hammer or other disturbance in the supply main. Through the provision of a highly dependable differential pressure type valve, it becomes possible to provide deluge valves of extremely large capacity that are free of mechanical latch devices or other retaining means of necessarily massive construction, requiring substantial force to effect release.

I claim:

1. A deluge valve for a fire extinguishing system of the dry-pipe type, comprising a valve body having a passage therethrough, a primary valve for controlling the flow through said passage, the valve being pivotally mounted to open in the direction of flow, a holding chamber, a holding valve within said chamber of greater area than the primary valve and adapted when held closed to hold closed the primary valve, means providing relatively restricted flow communication between the holding chamber and the passage on the inlet side of the primary valve, and means including a resilient diaphragm of substantially greater area than the flow communicating means and having one side in communication with the holding chamber and the other side in communication with the valve passage for transmitting sudden pressure changes therein directly to the holding valve.

2. A deluge valve for a fire extinguishing system, comprising a valve body provided with a substantially straight-through water passage, a primar valve for controlling the flow of water through said passage to the system from a source of supply, said valve being pivotally mounted to swing open in the direction of water flow through said passage, and means for holding said valve normally closed comprising a holding valve of greater effective area than the primary valve and connected thereto, a holding chamber having a port opening into the valve passage on the system side of the primary valve, said port being closed b the holding valve when the valve passage is closed by the primary valve, means for supplying water to the holding chamber at the pressure of the source of supply, said means including a flow-limiting orifice, and means for equalizing sudden pressure changes in supply pressure, said means including a flexible diaphragm interposed between supply source and holding chamber.

3. A deluge valve for a fire extinguishing system of the dry-pipe type, comprising a primary valve for controlling the admission of water to the system from a source of supply, said valve being pivotally mounted to open in the direction of flow from supply source to system, a holding valve of greater area than the primary valve and connected to move therewith, said holding valve being disposed at approximately a right angle to the primary valve, a holding chamber having a port adapted to be closed by the holding valve, means providing relatively restricted fiow communication between the supply source and the holding chamber to admit water at supply pressure to the holding chamber to maintain said valves closed by positive differential pressure on the holding valve, and means comprising a resilient diaphragm having one side in communication with the water in the holding chamber and the other side in communication with the water of the supply source for transmitting sudden pressure changes in the supply directly to the holding valve to prevent accidental release of the primary valve under the influence of water hammer in the main.

4. A deluge valve for a dry-pipe fire extinguishing system, said valve being of the difierential water pressure type having a primary valve in control of admission of water to the system from a source of supply, a secondary valve of greater effective area than the primary valve and adapted when closed to hold closed the primary valve, a holding chamber within which the secondary valve operates, a passage of restricted crosssectional area to provide limited fiow communication between the holding chamber and the source of supply to subject the secondary valve to water pressure at the pressure of the supply for slowly-occurring pressure changes, and means having large effective cross-sectional area; in comparison with the flow-communicating passage for rapidly equalizing water pressures within the holding chamber relative to supply pressures adjacent the primary valve, said means being movable to permit pressure equalization while maintaining a barrier against flow communication.

5. A deluge valve for a dry-pipe fire extinguishing system, said valve being of the difierential water pressure type having a primary valve in control of admission of water to the system from a source of supply, a secondary valve of greater effective area than the primary valve and adapted when closed to hold closed the primary valve, a holding chamber within which the secondary valve operates, a passage of restricted crosssectional area to provide limited flow communication between the holding chamber and the source of supply to subject the secondary valve to water pressure at the pressure of the supply for slow-occurring pressure changes, and means for rapidly transmitting to the holding chamber sudden changes in pressure occurring in the supply adjacent the primary valve, said means comprising a movable fluid-barrier of large efiective cross-sectional area relative to the flow-communicating passage, said means being exposed on one side to the interior of the holding chamber and on the other side to the source of supply in the vicinity of the primary valve.

6. A deluge valve for a fire extinguishing system of the dry-pipe type, comprising a valve body having a passage therethrough, a primary valve for controlling the flow through said passage, a holding chamber, a holding valve within said chamber adapted when closed to hold closed the primary valve, means providing relatively restricted flow communication between the holding chamber and the passage on the inlet side of the primary valve, means including a resilient diaphragm of substantially greater area than the flow communicating means and having one .side in communication with the holding chamber and the other side in communication with the valve passage for transmitting sudden pressure changes therein directly to the holding valve, and means for supporting the diaphragm against excessive displacement.

HOWARD G. FREEMAN.-

REFERENCES CITED The following references are of record in the file of this patent:

' UNITED sums PATENTS 2,366,520 Griflith Jan. 2, 1945

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