Abstract:
A fire suppression system includes system piping and at least one sprinkler with the system piping for delivering fire suppressant to the sprinkler. The sprinkler has an outlet and a temperature sensitive trigger with temperature sensitive trigger opening the outlet for dispersing fire suppressant when sensing temperatures associated with a fire condition. The system also includes a deluge valve that is in selective fluid communication with the system piping and has a normally closed condition whereby the system piping is normally dry. The deluge valve controls the flow of suppressant to the system piping and the sprinkler. A control system, which is in communication with at least one source of power, opens the deluge valve in a fire condition when the power source is in a powered condition and opens the deluge valve in a loss of pressure condition when the power source is in a loss of power condition.

Description:
This application claims priority from U.S. provisional application Ser. No. 60/381,315, filed May 17, 2002, entitled FIRE PROTECTION SYSTEM, by Eldon D. Jackson, the entire disclosure of which is incorporated herein by reference in its entirety. 
    
    
     TECHNICAL FIELD AND BACKGROUND OF THE INVENTION 
     The present invention relates to a control system for a sprinkler system and, more particularly, to a control system for a preaction sprinkler system. 
     There are several types of preaction systems, but all preaction systems typically employ closed sprinklers in the sprinkler system piping. The detection system may be hydraulic, pneumatic, or electric and may be actuated manually or by detecting a temperature rise or by other means. Typically, the detection system operates before the sprinkler fuses and sounds an alarm. Preaction systems are used in areas where it is desirable to keep water intrusion to a minimum, such as areas that are subject to high potential water damage or freezing of the system piping. 
     Current technology requires continuous power to the various components that control the opening and closing of the flow control valve. For example, in the trim piping for some preaction systems, a normally open solenoid valve is used to control the pressure in the priming chamber of the system control valve. The solenoid valve must be powered closed during normal system operation. When a fire occurs, the solenoid valve is de-energized and opens to release the main sprinkler system control valve. However, this requires back-up power and a continuous power condition for the solenoid valve, which may result in a high-heat condition and possible failure due to sticking and/or failure of the electrical coil of the solenoid valve. In order to make these systems fail-safe, the system relies on a loss of power condition to release the main valve to allow the system to operate. 
     Consequently, there is a need for a preaction system that can fail-safe but which can operate in a no-power condition. 
     SUMMARY 
     Accordingly, the control system of the present invention provides a supervised fail-safe electric release control system for a preaction system that can operate in a low power or loss of power condition. 
     In one form of the invention, a fire suppression system includes system piping, with at least one sprinkler for dispersing fire suppressant when sensing temperatures associated with a fire condition and a deluge valve. The deluge valve is in selective fluid communication with the system piping and has a normally closed condition whereby the system piping is normally dry. The fire suppression system further includes at least one normally open fire detector, which is adapted to detect temperatures associated with a fire and has an open no-fire condition state and a closed fire condition state and generates a fire condition signal when in the closed fire condition state. A control system is provided that monitors the pressure in the system piping and is in communication with the fire detector, a source of power, the deluge valve, and the system piping. The control system is adapted to actuate the deluge valve to open in response to a fire condition signal and a low pressure condition in the system piping. The control system includes a pneumatic actuator that is adapted to detect a drop in pressure in the system piping and to actuate the deluge valve between the closed condition and an open condition when the pneumatic actuator detects a drop in pressure in the system piping and when the control system experiences a loss of power from the source of power. The control system also includes a shut-off valve in communication with the deluge valve that is adapted to latch the deluge valve open once the deluge valve opens until manually shut-off. 
     In one aspect, the deluge valve includes an inlet chamber, an outlet chamber, a priming chamber, and a clapper assembly. The inlet chamber and the outlet chamber are separated from the priming chamber by the clapper assembly. The deluge valve further includes a priming line in fluid communication with the inlet and the priming chamber, which pressurizes the priming chamber. The clapper assembly opens the deluge valve in response to pressure in the priming chamber, with the control system controlling the flow from the priming line to the priming chamber to open the deluge valve. 
     In other a further aspect, the priming line includes at least one solenoid valve, which is actuated by the control system to open the deluge valve. Preferably, the priming line includes a second solenoid valve, with one of the first solenoid valve and the second solenoid valve comprising a normally closed solenoid valve and another of the first solenoid valve and the second solenoid valve comprising a normally open solenoid valve to control the flow of fire suppressant through the priming line. The control system actuates the normally open solenoid valve to close and the normally closed solenoid valve to open in response to the fire condition signal. 
     In another form of the invention, a fire suppression system includes a fire suppressant supply line, system piping, a pressure supervisory system, which monitors pressure in the system piping, and at least one sprinkler for dispersing fire suppressant when sensing temperatures associated with a fire condition. The fire suppression system also includes a control valve, which is in fluid communication with the system piping and the supply line. The control valve has a normally closed condition but is opened when a low pressure condition in the system piping and a fire condition occur. The fire suppression system further includes at least one fire detector, which is adapted to detect temperatures associated with a fire, and a control system, which is in communication with a power source, the fire detector, the pressure supervisory system, and the priming line. The control system is adapted to control the flow of suppressant in the priming line to open the control valve when detecting a fire condition signal and a low pressure condition in the system piping and, further, is adapted to open the valve when the power source is in a power loss state in response to a low pressure condition in the system piping. Preferably, the control system is also adapted to latch the valve open when the valve opens requiring manual closing of the valve. 
     In one aspect, the control system includes a shut-off valve to latch the control valve open when the control valve opens. 
     According to yet another form of the invention, the flow of fire suppressant from a fire suppression supply to sprinkler system piping is controlled by providing a deluge valve, which has a normally closed condition. The pressure in the system piping is monitored to detecting a low pressure condition in the system piping. The deluge valve is actuated when a low pressure condition and a fire condition is detected. Furthermore, when opened, the deluge valve is latched open so that the deluge valve must be manually shut down. 
     Accordingly, the fire protection system of the present invention can operate in both a powered state or condition and a loss of power state or condition while still providing a normally dry system. In a powered state, the control system opens the sprinkler system piping control valve only in a fire condition (i.e. when a sprinkler opens and a fire detector is actuated). In a loss of power state, the control system only opens the control valve when there is a loss of pressure in the sprinkler system piping (i.e. when a sprinkler opens). Furthermore, the control system latches the control valve open, requiring manual closing of the control valve. These and other objects, advantages, purposes, and features of the invention will become more apparent from the study of the following description taken in conjunction with the drawings. 
    
    
     
       DETAILED DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a piping diagram of the control system of a fail-safe preaction system of the present invention; 
         FIG. 1A  is a schematic diagram of the control system of a fail-safe preaction system of the present invention: 
         FIG. 2  is a schematic diagram of a control panel of the control system of  FIG. 1 ; 
         FIG. 3  is a release panel function table of the control panel of  FIG. 2 ; 
         FIG. 4  is a schematic diagram of another embodiment of a control system of the present invention; 
         FIG. 5  is a schematic diagram of a control panel of the control system of  FIG. 4 ; and 
         FIG. 6  is a release panel function table of the control panel of  FIG. 5 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to  FIG. 1 , the numeral  10  generally designates a control system of the present invention. As will be more fully described below, control system  10  is pneumatically pressurized to monitor the integrity of the sprinkler piping, fittings and sprinklers and acts as a fail-safe emergency backup to an electrical detection system. Control system  10  controls a preaction fire suppressant system in which the sprinkler piping system is normally dry and, therefore, may be installed in locations sensitive to water damage, such as an area subject to freezing. Control system  10  minimizes accidental water damage and, therefore, can be used in areas where detectors and/or sprinklers are easily damaged or broken. Furthermore, as will be more fully described, control system  10  may be used to control in a preaction system  11  to provide a fire protection environment with or without electrical power. 
     Referring again to  FIG. 1 , control system  10  controls the pressure in the priming chamber ( 14 ) of valve  12  to open and close valve  12 . When open, valve  12  delivers fire suppressant, such as water, to sprinkler system piping  16  and sprinklers (S, see  FIG. 1A ) of preaction system  11 . Valve  12  includes an inlet  20  and an outlet  22 , which is in communication with system piping  16 . Hereinafter, reference will be made to water, though it should be understood that other fire suppressant fluids may be used. Water is delivered to inlet  20  from water supply  23  through a water supply control valve  24 . Outlet  22  is connected to system piping  16  through a check valve  26 , which restricts the flow of pressurized air flow system piping  16  to valve  12  as will be more fully described below. 
     Valve  12  comprises a deluge valve and includes a body, which forms a passage between inlet  20  and outlet  22 , and a movable clapper (C. see  FIG. 1A ) which moves between a first position (shown in phantom) in which the passage is blocked to thereby close the valve and a second position (shown in solid lines) in which the passage is open to permit flow of water from inlet  20  to outlet  22 . Positioned above the clapper assembly is priming chamber  14 . When priming chamber  14  is sufficiently pressured, the clapper assembly is moved to its first or closed position to thereby close the valve. When pressure is released in the priming chamber, the clapper moves to its second position in which the passage is open to permit valve  12  to open. Further details of valve  12  are omitted, as valve  12  is conventional and available in a number of different configurations. Suitable deluge valves are available from The Viking Corporation of Hastings, Mich. 
     As best seen in  FIG. 1 , control system  10  includes a supply pressure priming line  30  with a normally open priming valve  32 , a strainer  34 , a restricted orifice  36 , and a check valve  38 . Priming line  30  supplies the system water supply pressure to the priming chamber  14  of valve  12  via priming outlet line  40  through a pressurized shut-off valve  42 . Priming outlet line  40  is also connected through a normally emergency release  44  (such as a manually operated valve) to a drain  45 . The flow of water through priming outlet line  40  is further controlled by a normally open solenoid valve  46  and a normally closed solenoid valve  48  and a pneumatic actuator  50 . As will more fully described below, solenoid valves  46  and  48  are actuated by a control panel  52  ( FIG. 1 ). In a set condition, water supply pressure is trapped in the priming chamber  14  of valve  12  by check valve  38 , normally closed emergency release  44 , normally closed solenoid valve  48 , and pneumatic actuator  50 . The water supply pressure in the priming chamber holds the clapper assembly of valve  12  on the valve seat until the pressure is released. 
     In order to detect when a sprinkler is opened, system piping  16  is supervised by an air supply  51  and one or more supervisory pressure switches  58  and  60 , which are in communication with control panel  52 . As noted above, valve  26  prevents the flow of pressurized air from system piping  16  to valve  12 . Control panel  52  is also in communication with one or more normally open detectors  56 , such as heat detectors, and optionally sounds an alarm  62  and further closes normally open solenoid valve  46  when detector  56  detects a fire condition as well a low pressure condition. In addition as noted, control panel  52  is in communication with pressure switches  58  and  60 , which detect the supervisory pressure in system piping  16 . 
     Pneumatic actuator  50  is also in communication with the supervisory air system that pressurizes sprinkler system piping and opens in response to a pressure drop in system piping  16 . When the sprinklers operate in response to a fire, the system supervisory air is lost and pressure switches  58  and  60  are actuated. Normally after receiving both signals from the pressure switches  58  and  60  and from detector  56 , control panel  52  energizes normally closed release solenoid valve  48  open so that pressure is released from priming chamber faster than it is supplied through restricted orifice  36 . Water entering piping system  16  increases the pressure on pressurized shut-off valve  42 , which shuts off the priming fluid to priming chamber  30  of valve  12  to thereby latch valve  12  open. 
     If system piping  16  and/or sprinklers are damaged and none-of the AC power or the stand-by battery power is available, supervisory switch  58  will cause control panel  52  to activate alarm  62 . In addition, normally open solenoid valve  46  will close to prevent valve  12  from opening and to prevent water flow from any of the open sprinklers. In the event of a fire, which will cause detector  56  to operate, control panel  52  will open normally closed release solenoid  48  so that the priming pressure will be released from priming chamber  14  and valve  12  will open and water will flow through the sprinkler system and trough the sprinklers. 
     If there is a loss of power while the system is flowing water, normally open release solenoid valve  46  will open and normally closed release solenoid valve  48  will close. Since the pressurized shut-off valve  42  is already pressurized closed to prevent pressure in the chamber from building up, the water from the main water supply  23  will continue entering the fire protection system and through any open sprinkler. 
     If there is a loss of power prior to operation, control system  10  will continue to operate on stand-by batteries  96  and  98  ( FIG. 2 ). Should the AC power and the stand-by batteries drop power to a point less than required to operate solenoid valves  46  and  48 , solenoid valves  46  and  48  will fail respectively open and close. However, as long as air pressure remains in the system piping, pneumatic actuator  50  will keep valve  12  from opening. If the system air pressure is lost, valve  12  will open allowing water to flow into the sprinkler piping and be discharged from any open sprinklers. 
     As noted above, system  10  includes an emergency release  44 . Emergency release  44  includes a handle, which when pulled permits the pressure from priming chamber  14  to be discharged through discharge line  47  to drain  45  so that valve  12  will open and water will flow in system piping  16 , which will actuate any connected alarms, but will not be discharged from any closed sprinklers attached to the system until a sprinkler is operated such as by a fire. 
     In this manner, control system  10  provides an electric pneumatic control system which converts to a pneumatic system once power is lost. 
     After a system has been subjected to a fire, the entire system must be inspected for damage or possible repair or replacement as necessary. Typically, if all system components are operational, the system is drained by an auxiliary drain  72  and by a system drain valve  74 . The inlet chamber of the valve  12  is drained by valve  76 . 
     In order to test the system on a regular basis, system  10  includes a water supply pressure gage and valve  80  and a normally closed alarm test valve  82 . The outlet of alarm test valve  82  is connected to a drain check valve  84 ′ which is connected to the output of pressure operated shut-off valve  44 . Test valve  82  is also connected in parallel to an alarm shut-off valve  86 , whose outlet is connected to a water monitor alarm  88  through a strainer  90 . Preferably, the piping connecting alarm shut-off valve  86  to water monitor alarm  88  includes an alarm pressure switch  92 . 
     As noted above, solenoid valves are actuated by control panel  52 . As best seen in  FIG. 2 , control panel  52  is communication with first and second solenoid valves  46  and  48  as well as with one or more fire detectors  56 , supervisory switches  58  and  60 , and an optional water flow pressure switch  57  ( FIG. 1 ). Fire detectors  56  may include, for example, conventional heat or smoke detectors, which preferably comprise open contact detectors that close to signal an alarm. Preferably, detectors  56  are chosen to have detection temperatures lower than the lowest temperature rated sprinkler being used. The sprinklers are preferably conventional heat triggered sprinklers and include a sprinkler body, which has an outlet, that is coupled and in fluid communication with the system piping  16 . The sprinklers further include frames and temperature sensitive triggers, which are positioned between the outlets and the frames, which break or release to open the outlets upon detecting temperatures associated with a fire. 
     Control panel  52  is a microprocessor controlled releasing panel and includes a microprocessor  52   a  and. at least one zone relay  52   b . Zone relay module  52   b  preferably comprises a commercially available zone relay module 4XCM part from The Viking Corporation of Hastings, Mich. Zone relay module  52   b  includes six relay contacts  53 , namely a detection contact  53   a , a supervisory contact  53   b , a release one contact  53   c , a release two contact  53   d , an alarm contact  53   e , and a trouble contact  53   f . Relay contacts  53  are actuated as follows. Detection relay contact  53   a  is actuated by detection circuits  56   a  or  58   a  or by water flow alarm switch circuit  57   a . Detection circuit  56   a  includes one or more detectors  56 . Supervisory relay contact  53   b  of zone relay module  52   b  is actuated by detection circuit  60   a . Release one contact  53   c  is actuated by detection circuit  56   a . The switch positions are shown in tabular form in  FIG. 3K  Release two contact  53   d  is actuated by detection circuit  58   a . Alarm relay contact  53   e  is actuated by detection circuits  56   a  or  58   a  or by optionally water flow switch circuit  57   a , Trouble contact  53   f  is actuated by a panel malfunction or fault in the field wiring. 
     Control panel  52  includes outputs for first and second solenoid valves  46  and  68  and for an alarm bell  62  and, optionally, a remote trouble signal  63 . In addition, control panel  52  preferably includes stand-by batteries  96  and  98  so that the control panel  52  will remain operational in the event of a power failure. Microprocessor  52   a , zone relay module  52   b , and the various supporting circuitry are preferably mounted on common circuit board, for example, a 110-volt mother board part commercially available from The Viking Corporation of Hastings, Mich. 
     SYSTEM OPERATION 
     Preaction system  11  preferably operates as a dry pipe system. As previously noted, solenoid valves  46  and  48  as well as pneumatic actuator  50  control the opening of control valve  12 , with solenoid valves  46  and  48  controlled by control panel  52  and actuator  50  controlled by the drop in pressure in the system piping. Control panel  52  is activated to close normally open solenoid  46  and open normally closed solenoid valve  48  in response to detectors  56  closing and by supervisory pressure switches  58  and  60  indicating a low pressure condition in system piping  16 . 
     In a normal operating condition, the water supply enters flow control valve  12  through inlet  20  of flow control valve  12  and the system water also enters priming chamber  14  of control valve  12  through the priming line  30 . Solenoid valve  46  is normally open, and solenoid valve  48  is normally closed. Pneumatic actuator  50 , however, is normally closed so that the priming fluid is trapped in priming chamber  14  by actuator  50 , solenoid  48 , and valve  38  in priming line  30 . If a fire is detected by detector  56  (which should close before the sprinklers are actuated), control panel  52  will sound an alarm. When one or more sprinklers then operate, the supervisory pressure switches  58  and  60  will actuate control panel  52  to close solenoid valve  46  and open solenoid valve  48  so that valve  12  will open. Only when control panel  52  detects or receives both fire condition and low pressure signals will control panel  52  actuate solenoid valves  46  and  48 . 
     If the AC power supply to control panel  52  fails, solenoid valves return to their non-energized normal states and valve  12  will open only when actuator  50  detects a loss of system pressure. 
     Once valve  12  opens, pressurized shut-off valve  42  closes to latch valve  12  in its open state until manually closed. 
     Referring to  FIG. 4 , the numeral  110  generally designates another embodiment of a control system for a fire protection system. The fire protection system includes a control valve  112 , preferably a deluge valve, which controls the flow of water from a water supply  123  to sprinkler system piping  116 , in a similar manner described in reference to the previous embodiment. In addition, similar to the previous embodiment, system piping  116  is pneumatically pressurized to monitor the integrity of the piping, fittings, and sprinkler and acts as a fail-safe emergency backup to the electrical detection system. 
     In the illustrated embodiment, control system  110  comprises a double interlocked fail-safe preaction control system which is also particularly suitable for use in an area where the environment is sensitive to water and, more particularly, in an environment where water can not flow into the sprinkler piping unless both the detector and the one or more sprinklers are operated, such as in the event of a fire. 
     Similar to the previous embodiment, supply water enters priming chamber  114  of valve  112  through a supply pressure priming line  130 . Priming line  130  includes a priming valve  132 , a strainer  134 , a restricted orifice  136 , and a check valve  138  whose outlet directs the flow of water through a priming outlet line  140  through a pressure operated shut-off valve  142 . Priming outlet line  140  is also connected to a normally closed emergency release valve  144  and a normally open solenoid valve  146  and a normally closed solenoid valve  148 . The pressure in priming outlet line  140  is maintained by check valve  138 , emergency release valve  144 , normally closed solenoid valve  148  and pneumatic actuator  150 , similar to the previous embodiment. Solenoid valves  146  and  148  are in communication with control panel  152 , which actuates solenoid valves  146  and  148  when control panel receives low-pressure signals from pressure switches  158  and  160  and a fire-condition signal from detector  156 . 
     In a fire condition, control panel  152  activates an alarm  158 , such as a pezio sounder, and initiates detection alarms. At this time, no water enters the sprinkler system piping. When a sprinkler operates, such as when detecting a temperature associated with a fire, switches  158  and  160  are actuated. Only when control panel  152  receives signals from switches  158  and  160  and, further, from detector  156 , control panel  152  opens normally closed solenoid valve  148  and closes normally open solenoid valve  146 . When solenoid valve  148  is open, pressure is released through pneumatic actuator  142 , which opens and discharges the priming fluid through discharge line  147  to drain  145  in response to a low pressure condition in system piping  116 . 
     If the system piping and/or sprinklers are damaged and either the AC power or the stand-by battery power is available, switches  158  and  160  will activate a trouble alarm when switches  158  and  160  detect a low-pressure in the supervisory air system. When the supervisory air drops below a pressure just above operation of pneumatic actuator  150 , control panel  152  will activate a trouble alarm. The second pole of supervisory switch  160  activates normally open release solenoid valve  146  to close to prevent water flow through any open sprinkler. In the event of fire that causes the detector  156  to operate when air pressure drops below the trouble air setting, air supervisory switch  158 , which is linked to normally closed solenoid valve  148 , will actuate valve  148  to open. When the normally closed release solenoid valve  148  opens, water will flow through any open sprinkler. 
     If the detection system is damaged or malfunctions, control panel  152  will go into an alarm mode. In the event of fire, valve  112  will not open and emergency release  144  must be pulled in order to provide water through the opened sprinklers. 
     If the AC power fails, system  110  will continue to operate on the stand-by batteries. Should the stand-by batteries fail prior to operation system, all alarms will be lost. However, when the DC power drops to a point less than required to operate normally closed solenoid valve, both solenoid valves return to their normal states allowing normally open solenoid valve  146  to open and solenoid valve  148  to close. As long as air pressure remains in piping system  116 , pneumatic actuator  150  will keep valve  112  from opening. If system air pressure is lost, valve  112  will open, allowing water to flow into system piping  116  and be discharged from any open sprinkler. 
     If all power fails while system  110  is flowing with water, normally open release solenoid valve  146  will open and normally closed release solenoid valve  148  will close. Since the pressurized shut-off valve  142  is already pressurized closed to prevent pressure in the chamber from building up, water from main supply line will continue entering system  116  through valve  112 , thus requiring manual shut-down of the fire protection system. 
     Anytime emergency release valve  144  is actuated, pressure is released from priming chamber  114  of valve  112  faster than it can be replaced through priming line  130 ; therefore, valve  112  opens. While water enters system piping  116 , the water will not be discharged until a sprinkler has operated, such as in the case of a fire. 
     It should be understood that since both fire protections systems of the present invention are normally dry, they may be installed in locations subject to freezing or in locations with equipment that is sensitive to water. In addition, systems  10  and  110  also provide excellent fire protection equipment with or without electrical power. Although the systems are equipped with backup batteries, which provide many hours of emergency power, the system will fail-safe and continue flowing until power is restored or the system is manually shut off. System  110  is particularly suitable where the environment is sensitive to water—where it is preferably that water can not flow into the system piping unless both a detector and sprinkler operates, such as in the case of a fire. 
     Referring to  FIGS. 5 and 6 , control panel  152  is similar to control panel  52  but includes in the detection circuit  158   b  for solenoid  148  a connection to air supervisory switch  158 . Reference is therefore made to control panel  52  for the remaining details of control panel  152 . 
     While several forms of the invention have been shown and described, other changes and modifications will now be apparent to those skilled in the art. Therefore, it will be understood that the embodiments shown in the drawings and described above are merely for illustrative purposes, and are not intended to limit the scope of the invention which is defined by the claims which follow as interpreted under the principles of patent law including the doctrine of equivalents.