Abstract:
A trim assembly for a fire protection system valve includes a mounting member and a piping assembly supported by the mounting member. The piping assembly includes a priming line with an inlet for receiving priming fluid from a fire suppressant fluid supply line and an outlet for delivering priming fluid to a priming chamber of the fire protection system valve. The inlet and the outlet are provided at the mounting member. The piping assembly also includes a component, which responsive to a control signal and/or a pressure differential. The component redirects priming fluid away from the outlet of the priming line in response to the control signal and/or the pressure differential for controlling the delivering of priming fluid to the priming chamber of the fire protection system valve. The piping assembly further includes a discharge outlet, with the priming line discharging the priming fluid to the discharge outlet when the component directs priming fluid away from the outlet of the priming line, which is preferably provided at the mounting member.

Description:
This application claims priority from U.S. provisional application Ser. No. 60/381,432, filed May 17, 2002, entitled FIRE PROTECTION VALVE TRIM ASSEMBLY 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 fire protection systems and, more particularly, to trim piping and components that control the operation of the main control valve of various fire protection systems. 
     Fire protection systems come in several forms. For example, deluge fire protection systems totally flood the protected area with pressurized water, with the system designed to empty until the control valve is closed by a release system, such as a hydraulic, pneumatic, electric, or manual release system. These deluge systems are often used in areas where a fire may spread rapidly or in an area that contains combustible material or solutions or the like. Other fire protection systems cycle between actuated and non-actuated states and, in some cases, only deliver water to the affected area when actuated by a heat sensor. 
     In some systems, the sprinkler system piping is filled with water prior to operation to permit a more rapid response. In other systems, the sprinkler piping is dry—these systems are primarily used to protect unheated structures where the system may be subject to freezing or in areas that are susceptible to water damage. 
     In each of these systems, the control valve that directs the flow of water to the sprinkler piping is controlled by a piping circuit or “trim piping”. Trim piping varies depending on the type of system, and, further, on the size of the valve. In addition, trim piping is typically installed at the field by the contractor installing the sprinkler piping. However, the trim piping typically includes a significant number of components and, hence, is relatively complicated to install. Furthermore, trim piping includes a large number of valves and other components that require a specific orientation to assure proper control by the trim piping. It has been found that given the complexity of the trim piping, components may be incorrectly located and/or installed in reverse orientation. Thus, the trim system may not properly control the flow control valve requiring re-work or re-installation of the trim piping. 
     Consequently, there is a need for a simplified process to install the trim piping and, further, in a manner which would provide greater flexibility in the trip piping application so that a single trim piping application may be used on different size control valves. 
     SUMMARY OF THE INVENTION 
     Accordingly, the present invention provides simplified trim piping assembly that can be assembled remotely from the site where the fire protection system is being installed and, further, can be tested prior to installation. 
     In one form of the invention, a trim assembly for a fire protection system valve includes a mounting member and a piping assembly mounted to the mounting member. The piping assembly includes a priming line having an inlet for receiving priming fluid from a fire suppressant fluid supply line and an outlet for delivering priming fluid to a priming chamber of a fire protection system valve. The piping assembly also includes a component that is responsive to a control signal or a pressure differential, which controls the flow of fire protection fluid from the inlet to the outlet of the priming line in response to the input for controlling the delivering of priming fluid to the priming chamber of the fire protection system valve to thereby open the fire protection valve. In addition, the piping system includes a discharge outlet, with the priming line discharging the priming fluid to the discharge outlet when the component redirects the flow of fluid away from the outlet of the priming line. Preferably, the inlet and outlet of the priming line and the discharge outlet provided at or near the mounting member. 
     In one aspect, the component comprises a solenoid valve, for example, a solenoid valve that is normally closed in a non-fire condition. Furthermore, the input comprises a control signal from a control panel, which actuates the solenoid valve when a fire condition is detected. Preferably, the control system includes at least one fire or heat detector that generates a fire condition signal when a fire is detected. When the control system detects the fire condition signal, the control system generates the control signal to actuate the solenoid valve. 
     In other aspects, the component comprises an actuator, such as a pneumatic actuator, which is in communication with and detects the pressure in the sprinkler system piping. When the actuator detects a pressure drop in the sprinkler system, for example when a sprinkler is opened, the actuator redirects the priming fluid away from the priming line outlet to thereby open the system valve. 
     In another aspect, the assembly also includes a pressure operated valve, such as a pressurized shut-off valve. For example, the shut-off valve may be configured close communication between the inlet and the outlet of the priming line when the shut-off valve detects the system valve opening to provide a hydraulic latch for the fire protection system valve. 
     In other aspects, the trim piping includes at least one alarm connection for connecting to an external alarm device. Preferably, the alarm connection is provide generally at the enclosure wall. 
     According to another aspect, the mounting member comprises an enclosure with a removable cover to provide access to the trim piping in the enclosure. 
     In another form of the invention, a fire protection system includes a fire suppressant fluid supply, sprinkler system piping, and a fire protection system valve having an inlet in communication with the fire suppressant fluid supply and an outlet in communication with the sprinkler system piping. The fire protection valve has a priming chamber and a clapper assembly, which closes communication between the inlet and the outlet of the valve when the priming chamber is pressurized and opens communication between the inlet and the outlet of the valve when the priming chamber is depressurized to control the flow of fire suppressant fluid from the fire suppressant fluid supply to the sprinkler system piping. The fire protection system also includes a trim assembly, which comprises a mounting member and a piping assembly. The piping assembly includes a priming line, with an inlet receiving priming fluid from the fire suppressant fluid supply line and an outlet for delivering priming fluid to the priming chamber of the fire protection system valve, and a component responsive to an input, such as a control signal or a pressure differential. The component redirects priming fluid away from the outlet of the priming line in response to the input for controlling the delivery of priming fluid to the priming chamber of the fire protection system valve to thereby open the control valve. The piping assembly also includes a discharge outlet, with the priming line discharging the priming fluid to the discharge outlet when the component redirects the priming fluid away from the outlet of the priming line. 
     In one aspect, the mounting member comprises an enclosure with an enclosure wall. The inlet and outlet of the priming line and the discharge outlet are provided at the enclosure wall to thereby provide a compact trim assembly. 
     In other aspects, the component comprises a solenoid valve, which is actuated by a control panel in response to a detector detecting a fire condition. Optionally, the solenoid valve comprises a normally closed solenoid valve. In a further aspect, the component also includes a pneumatic actuator that redirects priming fluid away from the outlet of the priming line in response to a pressure drop in the sprinkler system piping, which together with the solenoid valve provide a double-interlock system. 
     It can be appreciated that the present invention provides a compact trim assembly that can be pre-assembled and pre-tested prior to installation in a fire protection system. 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 schematic view of a pre-action fire protection system incorporating the trim assembly of the present invention that provides an electric/pneumatic release; 
         FIG. 2  is an enlarged view of the trim assembly of  FIG. 1 ; 
         FIG. 3  is a top plan view of the trim assembly of  FIG. 2 ; 
         FIG. 4  is a bottom plan view of the trim assembly of  FIG. 2 ; 
         FIG. 5  is a similar view to  FIG. 2  with the cover of the trim assembly removed; 
         FIG. 6  is an exploded perspective view of the trim piping and components of the trim assembly illustrated in  FIGS. 2-5 ; 
         FIG. 7  is a similar view to  FIG. 2  of a second embodiment of the trim assembly of the present invention, which provides a pneumatic release; 
         FIG. 8  is a top plan view of the trim assembly of  FIG. 7 ; 
         FIG. 9  is a bottom plan view of the trim assembly of  FIG. 7 ; 
         FIG. 10  is a similar view to  FIG. 7  with the cover of the trim assembly removed for clarity; 
         FIG. 11  is a similar view to  FIG. 2  of another embodiment of the trim assembly of the present invention incorporating an electric release; 
         FIG. 12  is a top plan view of the trim assembly of  FIG. 11 ; 
         FIG. 13  is a bottom plan view of the trim assembly of  FIG. 11 ; 
         FIG. 14  is a similar view to  FIG. 11  with the cover of the trim assembly removed for clarity; 
         FIG. 15  is a schematic view of a deluge fire protection system incorporating a trim assembly of the present invention, which provides a pneumatic release; 
         FIG. 16  is an enlarged view of the trim assembly of  FIG. 15 ; 
         FIG. 17  is a top plan view of the trim assembly of  FIG. 16 ; 
         FIG. 18  is a bottom plan view of the trim assembly of  FIG. 16 ; 
         FIG. 19  is a similar view to  FIG. 16  with the cover of the trim assembly removed for clarity; 
         FIG. 20  is an exploded perspective view of the trim piping and components of the trim assembly of  FIGS. 16-19 ; 
         FIG. 21  is a similar view to  FIG. 16  illustrating a trim assembly incorporating an electric release; 
         FIG. 22  is a top plan view of the trim assembly of  FIG. 21 ; 
         FIG. 23  is a bottom plan view of the trim assembly of  FIG. 21 ; 
         FIG. 24  is a similar view to  FIG. 21  with the cover of the trim assembly removed for clarity; 
         FIG. 25  is an exploded perspective view of the trim piping and components of the trim assembly of  FIGS. 21-24 ; 
         FIG. 26  is a similar view to  FIG. 21  illustrating another embodiment of the trim assembly of the present invention incorporating an electric/pneumatic release; 
         FIG. 27  is a top plan view of trim assembly of  FIG. 26 ; 
         FIG. 28  is a bottom plan view of the trim assembly of  FIG. 26 ; 
         FIG. 29  is a similar view to  FIG. 26  illustrating the trim assembly with the cover removed for clarity; and 
         FIG. 30  is an exploded perspective view of the piping and components of the trim assembly of FIGS.  26 - 29 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to  FIG. 1 , the numeral  10  generally designates a fire protection system incorporating a trim assembly  110  of the present invention. Fire protection system  10  includes a control valve  12 , which controls the flow of fire suppressant, such as water, from a fire suppressant supply  14  to sprinkler system piping  16 , which includes a plurality of sprinklers for delivering the fire suppressant to an area protected by system  10 . As will be more fully described below, trim assembly  110  controls the flow of fire suppressant through valve  12  using an electric/pneumatic release. Furthermore, trim assembly  110  provides a compact assembly that is pre-assembled and pre-tested prior to installation to ease the assembly of fire protection system  10 . 
     Fire suppressant supply  14  delivers fire suppressant to valve  12  through a water supply control valve  18 , whose output delivers fire suppressant to the input  20  of valve  12 . Output  22  of valve  12  delivers fire suppressant to the input  24  of a check valve  26 , whose output delivers fire suppressant to system piping  16 . Check valve  26  is provided to prevent the pressurized air in system piping  16  entering valve  12 . System  16  is supervised with pressurized air from air system  27 , which is used to monitor the pressure in fire protection system  10  to monitor the integrity of the sprinkler system piping and its components. In the illustrated embodiment, air system  27  delivers pressurized air to system piping  16  and monitors the changes in pressure in system  16  by one or more pressure switches  27   a.    
     In the illustrated embodiment, valve  12  comprises a deluge valve, which includes a priming chamber  30  and a clapper assembly. The clapper assembly opens and closes communication between inlet  20  and outlet  22  of valve  12  in response to pressure in priming chamber  30 , as is known in the art. Trim assembly  110  controls the pressure in priming chamber  30  and communicates with valve  12  and suppressant supply system  14  through by conduits  112 , for example, flex hoses. Trim assembly  110  also communicates with a control panel  28  (via wiring indicated by dotted lines in FIG.  1 ), which provides actuating signals to components within trim assembly  110  and also to components located exteriorly of trim assembly  110  to control the opening of valve  12  in response to low pressure signals from pressure switch  27   a  and in response to fire-condition signals from detector  40 . 
     Referring to  FIGS. 2-6 , trim assembly  110  includes a mounting member, such as an enclosure  114 , which supports and, preferably, houses trim piping (and components)  116  and provides access to various connections of trim piping  116 . As best seen in  FIG. 6 , trim piping  116  includes a solenoid valve  118  and pressure gages  120  and  122 , which provide pressure readings for the prime pressure and inlet pressure, as will be more fully described below, and a priming line  124 , which delivers prime pressure to priming chamber  30  of valve  12  from the fire suppressant supply line  14  ( FIG. 1 ) to control the position of clapper assembly  32 , which opens and closes communication between inlet  20  and outlet  22  of valve  12 . Priming line  124  includes an inlet  126 , a strainer  128 , a restriction  130 , a check valve  132  all in series and which communicate with a pressure operated shut-off valve  134 . Preferably, priming line  124  includes at or near its inlet a manual shut-off valve  136  so that the flow of priming fluid from supply system  14  can be blocked manually. 
     Pressure operated shut-off valve  134  is normally open and directs the priming pressure from priming line  124  (and hence from supply line  14 ) to a prime outlet  138 , which is in communication with priming chamber  30  via conduit  112 . To release the pressure in priming chamber  30 , trim piping  116  includes solenoid  118 , which is normally closed, and a pneumatic actuator  142 , which is also normally closed. As generally noted above, solenoid valve  118  is in communication with control panel  28  and is actuated to open when control panel  28  receives a signal from normally open detector  40 , such as heat detector, which is actuated in a fire condition. Even with solenoid valve  118  opened, however, the pressure in priming chamber  30  will not be released through solenoid valve  118  until pneumatic actuator  142  is opened. Pneumatic actuator  142  is in communication with the system piping pressure through inlet  144  and is normally closed but is opened when the sensing side of the actuator detects a drop in pressure in the sprinkler piping system. In a fire condition, when a sprinkler opens, the supervisory pressure in sprinkler piping  16  is reduced causing pneumatic actuator  142  to open. Thus, when control  28  receives a signal from detector  40  of a fire condition and one or more sprinklers open in response to a fire condition, control panel  28  actuates normally closed solenoid valve  118  to open and the pressure drop in system piping  14  opens pneumatic actuator  142  so that the pressure is released from priming chamber  30  faster than it is supplied through restricted orifice  130 . When pneumatic actuator and solenoid  118  are open, the priming pressure is directed to a drain  50  ( FIG. 1 ) through outlet  148 . Where pneumatic actuator  142  is open, but solenoid  118  is not open, the pressure in priming chamber will be maintained and the system will not trip until a fire condition is also detected by detector  40 . Thus, the present trim assembly provides a double interlock system. 
     Pressure operated shut-off valve  134  is in communication with the inlet pressure of valve  12  through inlet  140 . When valve  12  opens, the sensing end of pressurized shut-off valve  134  is pressurized causing valve  134  to close. When valve  134  closes, it shuts off the flow of priming water pressure to the priming chamber  30 , preventing deluge valve  12  from resetting even if the open releasing device (or devices) is closed and, thus, operates as a hydraulic latch requiring valve  12  to be manually shut-off. 
     As previously noted, trim assembly  110  includes a prime pressure gage  122 . Prime pressure gage  122  is in selective communication with priming line  124  via valve  150 . In this manner, gage  122  can be selectively actuated to test or measure the pressure in the priming line at the prime chamber outlet  138 , which provides a general measure of the pressure in priming chamber  30  of valve  12 . Optionally and preferably, trim piping  116  includes a manual emergency release valve  152 , such as a ball valve, which provides manual release of the priming pressure in priming chamber  30  of valve  12 . 
     Trim assembly  110  further includes an inlet pressure gage  120 , which is in communication with valve  12  through conduit  112  via an inlet connection  154 , which is connected to the inlet  20  of valve  12 . Optionally and preferably, gage  120  is connected to inlet connection  154  by a manual valve  156 , such as a ball valve, to provide selective readings of the pressure of the inlet of valve  12 . Trim assembly  110  optionally provides input to an alarm pressure switch (not shown) through connection  158 , which is in communication with inlet connection  154  through a manual valve  160 , which is preferably normally closed. In this manner, connection  158  provides an alarm test connection for trim assembly  110 . Similarly, trim assembly  110  includes a second input to a water motor alarm  52  through connection  160 , which is in parallel to connection  158  and which is isolated by manual valve  162 . System  110  further includes a third alarm connection  162 , which communicates with a second alarm pressure switch  54 , which is in turn in communication with control panel  28  and when actuated initiates control panel  28  to actuate audible alarm  58 . Preferably, trim assembly  110  includes a check valve  164 , which automatically drains the system after testing. 
     Referring to  FIG. 5 , preferably, connections or inlets  126 ,  140 , and  144  are accessible through enclosure  114 . Similarly, outlets or connections  138 ,  154 ,  158 ,  160 , and  162  are similarly accessible through enclosure  114  and are preferably located at upper or lower walls  114   a  or  114   b  of enclosure  114  to provide easy hook-up and connection to the various components of fire protection system  10 . As best seen in  FIG. 8 , connections  158 ,  160 , and  162  and outlet  144  are positioned at upper enclosure wall  114   a,  while outlets  154  and  138  (and drain outlet  148 ) and inlets  126  and  140  are located at lower enclosure wall  114   b.  In this manner, the various connections (inlets or outlets) are easily accessible and, further, are substantially aligned in two planes, which provides a simplified assembly that is easy to hook-up to the fire protection system and the various controls for the fire protection system. As noted above, the various connections for trim assembly  110  may be made to their respective piping components of the fire protection system by way of conduits, such as flex hoses or the like. In this manner, trim assembly  110  provides greater flexibility in the mounting of and location of the trim piping contained in trim assembly  110  and, further enables the same trim assembly piping to be used to control a wide range of valve sizes for any given fire protection system valve. 
     Preferably, enclosure  114  includes a removable cover  114   c  to provide access to the trim piping and components, for example the manual valves, within enclosure  114 . Cover  114   c  may be pivotally mounted to any of the enclosure walls or may be slidably mounted thereon. Cover  114   c  preferably includes an emergency door  115  with a handle  115   a,  which provides quick access to the emergency release valve  152 . Optionally, cover  114   c  may be eliminated in its entirety. Furthermore, a mounting member or frame may be substituted for enclosure  114 . As best in  FIG. 5 , back wall  114   b  of enclosure  114  may include mounting openings  114   a  so that enclosure  114  may be mounted to a fixed mounting surface, such as a structure, including a wall, a column or the like. 
     Referring to  FIGS. 7-10 , the numeral  210  designates another embodiment of the trim assembly of the present invention. Trim assembly  210  controls the opening and closing of valve  12  using a pneumatic release. As best seen in  FIG. 10 , trim assembly  210  includes an enclosure  214 , similar enclosure  114 , trim piping (and components)  216 , similar to trim piping  116 , with a priming line  224  that is in communication with water supply  14  through inlet  226  and, further, in communication with priming chamber  30  of valve  12  through outlet  238 . Similar to the previous embodiment, the flow of priming fluid through priming line  224  is controlled by a releasing device, namely pneumatic actuator  242 , and a pressurized shut-off valve  234  that is in communication with the inlet pressure of valve  12  through inlet  240 . Water supply pressure is trapped in priming chamber  30  of valve  12  by check valve  232  and pneumatic actuator  242 , which is in communication with sprinkler system piping  16  through inlet  244  and detects the pressure in piping  16 , similar to actuator  142 . Similar to the other connections, inlet  244  is preferably provided at the enclosure wall, such as the upper wall of the enclosure. 
     When the sprinkler system exhibits loss of supervisory air pressure, actuator  242  opens, thus, permitting the pressure to be released from priming chamber  30  of valve  12  faster than it is supplied through restricted orifice  230  of priming line  224  in a similar manner to the previous embodiment. In addition, when valve  12  operates, the sensing end of valve  234 , which is in communication with the system pressure through inlet  240 , will be pressurized causing valve  234  to close. When valve  234  is closed, it shuts off the flow of priming water to priming chamber  30 , preventing valve  12  from resetting even if the open releasing device (in this case actuator  242 ) is closed. Thus, the present trim assembly provides a single interlock system. 
     Similar to the previous embodiments, trim assembly  210  includes a plurality of test connections  258 ,  260 ,  262 , which may be optionally coupled to alarm switches for detecting the pressure of the water supply system through connection  254 , which couples to the inlet of valve  12 . 
     Referring to  FIGS. 11-14 , trim assembly  310  includes an electric release for valve  12 . As best seen in  FIG. 14 , trim assembly  310  includes an enclosure  314 , similar to enclosure  114  and trim piping (and components)  316 , similar to trim piping  116  of the first embodiment. In the illustrated embodiment, trim piping  316  eliminates the pneumatic actuator and, instead, provides an electric release of the priming pressure from priming chamber  30  of valve  12 . 
     Trim piping  316  includes a priming line  324 , which includes an inlet  326  that is in communication with the water supply  14 , and an outlet  338  for communicating with priming chamber  30  of valve  12 . Priming line  324  is similar to priming line  124  and includes a strainer  328 , an orifice  330 , and a check valve  332 , which are all in series with pressurized shut-off valve  334 . Pressurized shut-off valve  334  is normally open and directs the flow of priming fluid through outlet  338 , which, as previously described, is in communication with priming chamber  30  of valve  12 . Water supply pressure is trapped in priming chamber  30  by check valve  332  and a normally closed solenoid valve  318 . In a fire condition, when the detection system operates, control panel  28  energizes solenoid valve  318  to open relieving the pressure from priming chamber  30  of valve  12 , with the priming fluid exiting through outlet  348  to drain  50 . 
     Similarly, once valve  12  operates, the sensing end of valve  334  is pressurized causing valve  334  to close. When valve  334  closes, it shuts off the flow of priming fluid to priming chamber  30 , thus preventing valve  12  from resetting even if open releasing device is closed. 
     In a similar manner to the previous embodiment, test connections  358 ,  360 , and  362  may be provided at an upper wall  314   a  of enclosure  314 , while inlet and outlet connections  326 ,  338 ,  348 , and  340  and  354  are provided at lower wall  314   b  of enclosure  314 . In the illustrated embodiment, cover  314   c  of enclosure  314  is pivotally mounted to bottom wall  314   b  of enclosure  314  by a hinge  314   c ′ to provide access to trim piping  316 . Similarly, cover  314  preferably includes a door  315  that is pivotally mounted to cover  314  to provide access to emergency manual release  352 , similar to the previous embodiments. 
     Referring to  FIG. 15 , the numeral  410  generally designates another embodiment of a fire protection system incorporating a trim assembly  510  of the present invention. Fire protection system  410  includes a control valve  412  that controls the flow of fire suppressant, such as water, from water supply  414  to fire protection system piping  416 , which in turn delivers the fire suppressant to sprinklers  417 . Inlet  420  of valve  412  is in communication with the outlet of a water supply valve  418 , with outlet  422  of valve  412  directing the flow of the fire suppressant to system piping  416 . 
     Similar to the previous system, valve  412  is a deluge valve and includes a priming chamber  430  and a clapper assembly (not shown) that opens and closes communication between inlet  420  and outlet  422  in response to pressure in priming chamber  430 . The control of the pressure and priming chamber  430  is achieved by trim assembly  510 , which in the illustrated embodiment, provides a pneumatic release for the pressure in priming chamber  430 , as will be more fully described below. 
     Similar to the previous embodiments, fire protection system  416  is supervised by air, which is delivered by an air supply system  425  that delivers air through a plurality of valves (which are not described in greater detail herein as they are conventional), which deliver pressurized air to system  416  and which monitor the pressure in system  416  and, further, provide input to trim assembly  510 . 
     Referring to  FIGS. 16-20 , trim assembly  510  includes trim piping (and components)  516  that are housed in an enclosure  514 , similar to the previous enclosures. Trim piping  516  has a number of components in common with the trim piping of the previous embodiments and includes a priming line  524  that includes an inlet  526 , which is in communication with water supply  414 , and an outlet  538 , which is in communication with priming chamber  430  of valve  412 . In a set condition, the fire suppressant supply pressure is trapped in priming chamber  430  by check valve  532 , an actuator  542 , and normally closed pressure operated release valve  543 . Pneumatic actuator  542  is in communication with the supervisory system air through inlet  544 , which connects to the air supply system  425 , and opens when actuator  542  detects a pressure drop so that priming fluid will be discharged to drain  450  through discharge outlet  548 . 
     Pressure operated release valve  543  is in communication with the system pressure through inlet  540 . When valve  12  operates, the sensing end of pressure operated release valve  543  is pressurized, and pressure operated release valve  543  will operate to continually vent the priming chamber to drain  450  to prevent valve  12  from resetting even if open releasing device is closed. In this manner, valve  12  can only be reset after the system is taken out of service and the outlet chamber of valve  12  and associated trim piping are depressurized and drained. It can be appreciated that trim assembly  510  operates in the event of air supply failure and leakage of air from pneumatic release system. If air supply is not restored to the pneumatic release system, pneumatic actuator  542  will open venting the priming pressure from priming chamber  430  of valve  412  to thereby open valve  412 . 
     Trim assembly  510  preferably includes similar test connections  558 ,  560 , and  562 , which communicate with the inlet pressure of valve  512  via inlet connection  554  similar to the previous embodiments. 
     Referring to  FIGS. 21-24 , another embodiment  610  of the trim assembly of the present invention is illustrated. Trim assembly  610  is similar to trim assembly  510  and includes many common components with trim piping  516  but includes an electric release for valve  412 . Referring to  FIG. 24 , trim piping  616  of trim assembly  610  includes a priming line  624 , which communicates with the water supply  414  through inlet  626  and delivers priming pressure to priming chamber  430  of valve  412  through outlet  638 . Priming pressure is maintained in priming chamber  430  by check valve  632 , normally closed solenoid  618 , and by normally closed pressure operated release valve  643 . For further details of the alarm connections, reference is made to the previous embodiments. 
     When a fire condition is detected by a detector (not shown but similar to detector  40 ), a control panel (similar to control panel  28 ) will open normally closed solenoid valve  618  to relieve the priming pressure from priming chamber  430  of valve  412  and direct the flow of priming fluid to drain  450  through outlet  648 . When valve  412  operates, the sensing end of pressure operated release valve  643  is pressurized causing valve  643  to operate and to discharge priming fluid from priming chamber  430  to drain  450  through outlet  640 , which prevents valve  412  from resetting even if the open releasing device is closed. 
     Referring to  FIGS. 26-30 , the numeral  710  generally designates another embodiment of the trim assembly of the present invention, which provides an electric/pneumatic release of valve  412 . Trim assembly  710  includes trim piping (and components)  716  which are housed in an enclosure  714 , similar to the previous embodiments. Trim piping  716  includes a combination of components included in trim assemblies  510  and  710 . Trim piping  716  includes a priming line  724 , which directs priming fluid from water supply  414  to priming chamber  430  of valve  412 , and controls the flow of priming fluid by a normally closed solenoid valve  718  and a pneumatic actuator  742 . Pneumatic actuator  742  is in communication with the supervisory air system  425  and opens in response to a drop in pressure in the supervisory air system, which is indicative of a sprinkler opening in response to a fire, for example, as noted above. However, priming pressure is not discharged or relieved from priming chamber  430  until solenoid valve  718  is opened. Solenoid valve  718  opens in response to signals from a control panel (such as control panel  28 ), which is in communication with detectors, such as detector  40 . Thus, valve  412  will not open until both the electric detection system activates solenoid valve  718  and supervisory pressure in sprinkler system  416  has been lost. Similarly, once valve  412  has been opened, pressure operated release valve  743  opens to vent the priming chamber to drain  450  through outlet  740  and further remains open, preventing valve from resetting until it is manually reset. 
     While several forms of the invention have been shown and described, other forms will now be apparent to those skilled in the art. For example, while several forms of the trim piping have been illustrated, it should be understood that these are just exemplary and are not intended to limit the scope of this invention. Furthermore, while trim assembly has been illustrated with an enclosure, the various trim piping and connections can be mounted on a frame or other support or a planar mounting member, with the various inlets and outlets or connection provided at or near the mounting member while still providing a compact assembly that can be pre-assembled and pre-tested prior to installation at the fire protection system site. 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.