Field convertible valve and sprinkler system

Abstract

A fire suppression sprinkler system convertible between a wet and a dry mode of operation is disclosed. The system features a field convertible valve having a bypass loop with a bypass valve for selectively configuring the valve for wet or dry mode operation. For dry mode operation, the bypass valve is open. The field convertible valve also has a system actuator, a gas control valve and a water supply shut-off valve which are open in the dry mode. In the wet mode of operation, the bypass valve is open and the gas control and water supply shut-off valves are closed. The field convertible valve operates in a latch mode controlled by the system actuator in the dry mode, and as a flapper valve in the wet mode of operation. A method of converting the mode of operation of the sprinkler system is also disclosed.

1 . A valve for controlling fluid flow, said valve comprising:
 a chamber having an inlet and an outlet;   a seat positioned within said chamber downstream of said inlet;   a closing member positioned within said chamber and movable into and out of engagement with said seat to control fluid flow through said chamber;   a latch positioned within said chamber, said latch being movable between a first position engaging said closing member for maintaining said closing member in engagement with said seat, and a second position disengaged from said closing member and allowing said closing member to move out of engagement with said seat;   a latch actuator mounted on said valve and engaged with said latch for moving said latch between said first and second positions;   a bypass loop providing fluid communication between said inlet upstream of said seat and said chamber downstream of said seat; and   a bypass valve positioned within said bypass loop, said valve being openable and closeable for controlling the flow of fluid through said bypass loop.   
   
   
       2 . A valve according to  claim 1 , further comprising a gas conduit in fluid communication with said chamber downstream of said seat, and a gas control valve positioned within said gas conduit for controlling flow of gas to said chamber. 
   
   
       3 . A valve according to  claim 1 , wherein said closing member is pivotably mounted within said chamber for pivoting motion into and out of engagement with said seat. 
   
   
       4 . A valve according to  claim 3 , wherein said latch is pivotably mounted within said chamber for pivoting motion into and out of engagement with said closing member. 
   
   
       5 . A valve according to  claim 4 , wherein said latch actuator comprises:
 a cylinder mounted on said valve;   a piston reciprocably movable within said cylinder; and   a piston rod having one end attached to said piston and an opposite end engageable with said latch for moving said latch into engagement with said closing member upon motion of said piston.   
   
   
       6 . A valve according to  claim 4 , wherein said latch actuator comprises:
 a sub-chamber positioned adjacent to said chamber; and   a flexible diaphragm partitioning said chamber from said sub-chamber, said diaphragm being attached to said latch, wherein increased fluid pressure within said sub-chamber deflects said diaphragm toward said chamber thereby moving said latch into engagement with said closing member.   
   
   
       7 . A fire suppression sprinkler system convertible for use as a wet system or a dry system, said sprinkler system comprising:
 a source of pressurized liquid;   a piping network in fluid communication with said liquid source;   a plurality of sprinkler heads mounted on said piping network for discharging said liquid in the event of a fire;   a first valve positioned in said piping network between said liquid source and said sprinkler heads for controlling flow of said liquid thereto;   a bypass loop providing fluid communication between a point upstream of said first valve and downstream thereof, a bypass valve being positioned in said bypass loop for controlling flow of said liquid therethrough;   a source of pressurized gas;   a gas conduit providing fluid communication between said gas source and said piping network downstream of said first valve, a gas control valve being positioned within said gas conduit; and   a system actuator in fluid communication with said gas source, said liquid source and said first valve, said system actuator opening said first valve in response to a drop in gas pressure within said piping network when said system is operated as a dry system, said first valve opening in response to flow from at least one of said sprinkler heads when said system is operated as a wet system.   
   
   
       8 . A fire suppression sprinkler system according to  claim 7 , wherein said first valve comprises:
 a chamber having an inlet and an outlet;   a seat positioned within said chamber downstream of said inlet;   a closing member positioned within said chamber and movable into and out of engagement with said seat to control fluid flow through said chamber;   a latch positioned within said chamber, said latch being movable between a first position engaging said closing member for maintaining said closing member in engagement with said seat, and a second position disengaged from said closing member and allowing said closing member to move out of engagement with said seat;   a latch actuator mounted on said valve and in fluid communication with said system actuator, said latch actuator being engageable with said latch for moving said latch between said first and second positions;   a bypass loop providing fluid communication between said inlet upstream of said seat and said chamber downstream of said seat; and   a bypass valve positioned within said bypass loop, said valve being openable and closeable for controlling the flow of fluid through said bypass loop.   
   
   
       9 . A fire suppression sprinkler system according to  claim 8 , wherein said gas conduit is in fluid communication with said chamber downstream of said seat. 
   
   
       10 . A fire suppression sprinkler system according to  claim 8 , wherein said closing member is pivotably mounted within said chamber for pivoting motion into and out of engagement with said seat. 
   
   
       11 . A fire suppression sprinkler system according to  claim 8 , wherein said latch is pivotably mounted within said chamber for pivoting motion into and out of engagement with said closing member. 
   
   
       12 . A fire suppression sprinkler system according to  claim 8 , wherein said valve actuator comprises:
 a cylinder mounted on said first valve and in fluid communication with said system actuator;   a piston reciprocably movable within said cylinder; and   a piston rod having one end attached to said piston and an opposite end engageable with said latch for moving said latch into engagement with said closing member upon motion of said piston.   
   
   
       13 . A fire suppression sprinkler system according to  claim 8 , wherein said latch actuator comprises:
 a sub-chamber positioned adjacent to said chamber and in fluid communication with said system actuator; and   a flexible diaphragm partitioning said chamber from said sub-chamber, said diaphragm being attached to said latch, wherein increased fluid pressure within said sub-chamber deflects said diaphragm toward said chamber thereby moving said latch into engagement with said closing member.   
   
   
       14 . A fire suppression sprinkler system according to  claim 7 , further including a temperature sensor positioned proximate to said piping network, said temperature sensor providing a signal at a predetermined ambient temperature acting as a warning to convert said system from a wet mode to a dry mode of operation. 
   
   
       15 . A method of converting a fire suppression sprinkler system for use as a wet system or a dry system, said method comprising:
 providing a source of pressurized liquid;   providing a piping network in fluid communication with said liquid source;   providing a plurality of sprinkler heads mounted on said piping network for discharging said liquid in the event of a fire;   providing a first valve positioned in said piping network between said liquid source and said sprinkler heads for controlling flow of said liquid thereto;   providing a bypass loop for fluid communication between a point upstream of said first valve and downstream thereof, a bypass valve being positioned in said bypass loop for controlling flow of said liquid therethrough;   opening said bypass valve to convert said system into a wet system;   closing said bypass valve to convert said system into a dry system;   providing a source of pressurized gas;   providing a gas conduit for fluid communication between said gas source and said piping network downstream of said first valve, a gas control valve being positioned within said gas conduit;   opening said gas control valve to convert said system into a dry system;   closing said gas control valve to convert said system into a wet system;   providing a system actuator in fluid communication with said gas source, said liquid source and said first valve;   providing a shut-off valve between said liquid source and said system actuator;   opening said shut-off valve to convert said system to a dry system; and   closing said shut-off valve to convert said system to a wet system.   
   
   
       16 . A method according to  claim 15 , further comprising:
 providing a temperature sensor;   sensing ambient temperature proximate to said piping network;   providing a signal when said ambient temperature drops below a predetermined threshold; and   converting said sprinkler system from a wet system to a dry system upon receipt of said signal.