US1504831A - Automatic device for draining variable-pressure-alarm systems - Google Patents

Description

Aug. 12 1924.

H. W. PARK AUTOMATIC vDEVICE FOR DRAINING VARIABLE PRESSURE ALARM SYSTEMS Filed Dec. 51 `1921 Patented Aug. 12, 1924.

Unirse STATES PATENT OFFICE.

HALFORD W. PARK, OF SCARSDALE, NEW YORK, ASSIGNOR TO ROCKWO'OD SPRINKLER COMPANY OF MASSACHUSETTS, OF WORCESTER, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS.

AUTOMATIC DEVICE FOR DRAINING VARIABLEPRESSURE-ALRM SYSTEMS.

Application filed December 31, 1921.

To all whom t may concern:

Be it known that I, HALFORD W. PARK, a citizen of the United States, residing at Scarsdale, in the county of lVestchester and State of New York, have invented a new and useful Automatic Device lfor Draining Variable-PressureAlarm Systems, of which the following is a specification.

This invention relates to an automatic device for controlling thel supply and discharge of water under pressure for operating a fire alarm in connection with an automatic sprinkler system.

The principal objects of the invention are to provide means which will insure that when the alarm valve check lifts from its seat due to a flow of water past it to supply an open sprinkler all the water discharged through the pipe and spaces connecting the annular port of the alarm valve with the Ygong-actuating mechanism will be utilized without waste for alarm purposes, to provide means which will insure that when the check closes the water thereby left trapped in the alarm valve system will be drained forthwith leaving the alarm valve connecting pipe and spaces in their normally empty condition and thus automatically ready for further operation; to provide a construction in which, although both of the above objects are attained, no alarm will result from the uncovering of the annular port as the eiTect of mere water hammers transmitted to the alarm valve by the water in the supply pipe of the Vsprinkler system; toprovide a system in which there are no moving parts except a diaphragm and valve, nothing to create friction and nothing to corrode.

Further objects and advantages of the invention will appear hereinafter.

Reference is to be had to the accompanying drawingy which is a sectional view of a part of a sprinkler system showing a preferred form of this invention applied thereto.

I have shown the invention as used in connection with a variable pressure alarm or check valve 10, in this instance used in coni nection with a. water main 11 under high pressure and a stand pipe 12 to which the various sprinkler' heads are connected. When the valve 10 opens, either on account of reduction in the pressure above it, or for any other reason, water will iiow as usual Serial No. 526,428,

through a pipe 13, the end of which is connected with an annular port in the valve seat which is normally closed by the valve 10. The pipe 13 is shown as feeding the usual retarding chamber 16 which is connected byV a pipe 17 with a water motor alarm device9, located at any desired place and adapted to be operated by the flow of water from the retarding chamber to sound an alarm. The parts so far described are of .the usual construction and serve the usual purposes. This invention does not need to be used with a retarding chamber, as it can serve for retarding purposes itself to prevent sounding of the alarm in case of water hammer, with modications within the skill of those skilled in the art.

In order to discharge the water from the retarding chamber it has been customary heretofore to provide it with a constantly open drain outlet of small area which will, of course, discharge water all the time the retarding lchamber is being filled and all the time that the alarm is operated. In order to secure suflcient operating pressure at the gong this drain opening'has to be made small and therefore it takes a long time for the retarding chamber and connecting pipes to be drained by it after the alarm valve 10 is closed. As stated above, this inw vention involves means by which all the water that flows by the alarm valve 10 through the pipe 13 will be delivered into the retarding chamber or the alarm motor system without waste and when the valve 10 closes again the water will immediately discharge from the retarding chamber into the atmosphere at a rapid rate and this discharge will continue until the retarding chamber and connecting pipes and spaces are empty. The rapidity with which the parts arelbrought back to normal condition for operation again permits the real function of the retarding chamber to be maintained by preventing water hammers, even if occurring in close succession from starting the alarm to operate.

, For these purposesl can attach the device anywhere inthe pipe line between the alarm valve 10 and the water motor 9, but I have shown it as connected to the bottom of the retarding chamber. Below the pipe 13 there is a pipe 21 provided at the top with a Pitot tube 22 in the pipe 13. This Vislturned toward YVthe alarm valve Yl() and therefore when 'water flows toward the re-V tarding chamber from the main valve some jof it will be forced to flow. down thistube and through the pipe21 into a pressure chamber 23. Yrllhis exerts considerable pres- Y sure on a flexible diaphragm 24 constituting the top of that chamber. Above this chamrber and diaphragm is a second or suction chamber 26. Attached tothe diaphragm in y the suction chamber is a weighted valve 29 port communicates with Va Vdischarge pipe `atthetop for discharging'water from the system into the open air. Also communicating with the top of the suction chamber 26 there is a pipe 33`leading intofthe pipe 13. At the top of this there isa Pitot tube 35 somewhat larger than the Y tube 22 and with its curved end turned in a the opposite direction.

l Y Y is shut and the system is drainedv there is When the clapper of the main alarm valve very little hydrostatic pressure on the opposite surfaces of the diaphragm in the two i' f chambers 'and what there is is substantially kvequal'.

iVhenever the intoY the iretarding chamber, the action of this flow of water imbalances the pressure in the twoA chambers 23 and'26.

rlhe unb-alancing ofthe pressure is caused fby two forces assisting each other. The first force is .the differencerin the hydrostatic pressure on the two chambers. The presy Ysure on the pressure chamber is greater-than the pressure oni the suction-'chamber because Ytliefformer is va closed chamber'while the latter is open to theY atmosphere; The second. force is `the difference in pressure on thevtwo chambers -dueto the litot` tubes.

s The velocity `ofthe water throughthe pipe V13' causes an additional pressure on the "'openingfof the Ptot tube 22 connected to the pressure chamber, which additional Vpres- Vsureis transmitted toV the lower surface of Vthe diaphragm. The velocity of *the water f through the'pipe 13 causesV a reduction in pressure on the Pitot tube 35 connected kto the upper chamber which reductionin pressure is'transmitted to the upper surface .of the diaphragm. Either the difference in the forcel'of the 'hydrostatic heads alone7 or the Vdifference inrvelocityl heads alone will cause Vthe diaphragm to rise. Y The valve having once risen Vit -will lremain on the valve seatV holding the vent holejclosed as long las Water yis flowing'in the pipe., V

' As soon as the water flow stops,'however, the diilerence in velocity head disappears The valve 29 therefore remains in Y its'lolwest position leaving the vent hole 30 Y open to the atmos here.

K valve 10 opens and t e water starts to flow and the hydrostatic heads on the two chambers becomes equal so that the diaphragm tends to fall back to the position shown. The only force holding the valve up to the valve seat is the hydrostatic pressure due to the head of water from the water motor acting on the valve in the veut hole. The cast iron weight is heavy enough so that this head will not support it and it falls back into its original position leaving the vent hole open and free to drain the retarding chamber, which completes the operation. lt will be noted that when the valve seats on the vent hole, then the hydrostatic head on each chamber becomes equal, both chambers becomes closed to the atmosphere, therefore, were it not for the Pitot tubes the valve would fall away from the vent hole. The

Vdiii'erence in velocity head due to the tubes is the force that holds the valve on the seat while water is flowing.

lt is to be observed that while the water is flowing the force holding the valve on its seat continually increases untilvthe maximum force is obtained when the retarding chamber and the pipe to the water motor nozzle are completely filled. lf there should bea slight leak around the valve 29 while it is seated it would not affect the operation of the alarm. It is to be noted that there are no moving parts in the device except the diaphragm and nothing to present any friction -or to make it possible for the parts 1o corrode or fail to operate. It depends solely and directly upon the laws of hydrostatics.

Although l have illustrated and described only a single form of the invention, I am aware of the fact that modifications can be made therein by any person Vskilled in the art without departing from the scope of the invention as expressed in the claims. Therefore, I do not wish to be limited to all the details of construction herein shown and described but what I do claim is zl. In an automatic alarm valve system, the combination 'with a main alarm valve, a water motor alarm, and a conduit controlled by the alarm valve for conducting water from the riser to the motor when the alarm valve opens, of an upwardly opening port for discharging the water from the system. a valve below it adapted to close the port from below and adapted to open the port by force of gravity, a diaphragm having a chamber behind it, means for conducting water to increase the pressure in said chamber when the water flows to the water motor, whereby said valve is held up in opposition to its weight against the valve seat to close it by the force of thewater flowing through the system from the riser to the water motor and whereby when it becomes seated the hydrostatic head of water above it will assist in holding it to its seat, said valve hav-ing sulicient weight to cause it to fall away from the seat whenever held only by the hydrostatic head in the system behind said diaphragm.

2. In a device of the character described, the combination of a retarding chamber, a conduit for leading water thereto, a valve seat opening upwardly for discharging the water therefrom connected with said conduit, a chamber below the valve seat, an upwardly operating valve in said chamber, a pressure chamber connected with said conduit, means whereby the flow of water along the conduit will increase the pressure in the pressure chamber, said valve having a weight suiiicient to cause it to drop away from the seat when held to it by nothing but the hydrostatic head above it in said retarding chamber and system, a diaphragm separating said chambers and supporting said valve, and means whereby when the valve has once closed the hydrostatic head will assist in holding it against the seat.

3. In a device of the character described, the combination with an alarm motor and a pipe for conducting water thereto, of a Pitot tube projecting into said pipe and having its curved admission end extending toward the source of pressure in the conduit, two chambers below the pipe one communicating with said tube, the other chamber having an outlet ort at the top and communicating with t e pipe, a 'valve in the second chamber, adapted to rise therein and close the port, and a diaphragm separating said chambers and connected with the valve for transmitting the pressure due to the velocity of water past the Pitot tube to said valve to cause it tobe elevated and seated.

4. In a device of the character described, the combination with a retarding chamber and a pipe for conducting water thereto, of a pair of Pitot tubes extending from said pipe and projecting into it in opposite directions, two chambers below the conduit, each communicating with one of said tubes, one of said chambers constituting a pressure chamber, the Pitot tube communicating with which has its curved admission end extending toward the source of pressure in the conduit, the other chamber having an outlet opening at the top and also communicating with the other Pitot tube, a valve in the second chamber adapted to rise therein and close the outlet port, and a flexible diaphragm between the two chambers to which diaphragm the valve is connected.

5. In a device of the character described,

the combination with a. retarding chamber curved admission end extending toward the source of pressure in the conduit, the other chamber having an outlet opening at the top and also communicating with the conduit, a valve in the second chamber adapted to rise therein and close the port, and a flexi-. ble diaphragm separating said chambers for transmitting the pressure due to the velocity of water past the Pitot tube to said valve to cause it to be seated, on which diaphragm is a weight located in the pressure chamber, said valve being attached to the top of said diaphragm.

6. In a device of the character described, the combination with a conduit for conducting water, of a litot tube extending from said conduit and projecting into it two chambers, the Pitot tube communicating with one of said chambers and having its curved admission end extending toward the source of pressure in the conduit, the other chamber having an outlet opening and communicating with the conduit, a valve in the second chamber adapted to close the port, and a flexible diaphragm separating said chambers for transmitting the pressure due to the velocity of water past the Pitot tube to said valve to cause it to be seated, said valve being attached to said diaphragm.

7. In an automatic alarm valve system the combination with a main alarm valve, a water motor alarm, and a conduit controlled by the alarm valve for conducting water from the riser to the motor when the alarm valve opens, of a port for discharging the water from the system, a valve adapted to close the port, a diaphragm having a chamber behind it, means for directing the water in a course to increase the pressure in said chamber when the water flows to the water motor, whereby said valve is held against the valve seat to close it by the Jforce of the water flowing through the system from the riser to the water motor and whereby when it becomes seated the hydrostatic head of water above it will assist in holding it to its seat.

8. In an automat-ic alarm valve s stem the combination with a main alarm va ve, a water motor alarm, and a conduit controlled by the alarm valve or conducting water from the riser to the motor when the alarm valve opens, of a port for discharging the water from the system, a valve adapted to close the port, a diaphragm having a chamber beyond it, means whereby the pressure in said chamber is decreased when the water Hows to the water motor, whereby said valve is held against the valve seat to close it by the force of the water flowing through the system from the riser to the water motor.

In testimony whereof I have hereunto atlixed my signature.

HALFORD W. PARK.

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