CN117651587A

CN117651587A - Pneumatic valve

Info

Publication number: CN117651587A
Application number: CN202280033255.0A
Authority: CN
Inventors: 塞奥佐罗斯·库佐斯
Original assignee: Lexton Fire Extinguishing Co ltd
Current assignee: Lexton Fire Extinguishing Co ltd
Priority date: 2021-04-08
Filing date: 2022-03-15
Publication date: 2024-03-05

Abstract

The present invention relates to a pneumatic valve for a fire extinguishing system, a fire extinguishing system comprising the pneumatic valve of the present invention, and a method for operating the fire extinguishing system of the present invention.

Description

Pneumatic valve

Technical Field

The present invention relates to a pneumatic valve (gas-operated valve) for a fire extinguishing system, a fire extinguishing system comprising the pneumatic valve of the present invention and a method for operating the fire extinguishing system of the present invention.

Background

The fire suppression system may be activated manually or automatically. An example of an automated system is a spray system that is activated in response to detecting heat. The system is defined by a network of water pipes suspended from the ceiling of the building, interspersed with a plurality of showers. Each showerhead has a plug that is designed to burst or melt in response to the application of heat. In this way, the system effectively extinguishes a localized fire by activating one or more of the showerheads, or a larger fire by activating multiple showerheads.

Spray systems typically use water as a medium, but water is not suitable for extinguishing all types of fires. In the event of an electrical fire, the application of water to the fire will potentially lead to further spread of the fire. In addition, the showerhead is activated only after the hot gases generated in the event of a fire heat the temperature sensitive plugs. Thus, the hot gases will have to be relatively localized in order to activate the showerhead, potentially causing a delay between the occurrence of the fire and activation of the fire suppression system.

For applications such as electrical cabinets where direct aiming at the fire is desired, a system is known that provides a direct path inside the cabinet. Such systems use a heat sensitive pipe designed to burst when a certain temperature is reached. When the pipe bursts, the fire extinguishing material spreads from the point of bursting directly onto the affected area of the electrical cabinet, thereby directly treating the heat source.

An example of a large system that may not be desirable to use water is a pneumatic system that uses a series of heat sensitive tubing in the vicinity of the device to be protected. The pipe is connected to a cartridge containing fire extinguishing material. When the pipe bursts, the system loses pressure and causes the cartridge to deliver fire suppression material to a plurality of valves that are not directly connected to the pipe. The pressure of the fire extinguishing material causes the cap to blow off from each valve so that the fire extinguishing material can be delivered to the fire source. Such a system can effectively extinguish fires in a specific area or more, and the response time may be shortened because the system must first detect a pressure loss due to a burst of pipes before delivering the fire extinguishing material to the heat sensitive pipes through a separate pipe or pipe network.

Some pneumatic systems also provide a manual actuator that, when actuated, reduces the pneumatic pressure in the system. The manual actuator provides an operator with a method of rapidly deploying the fire suppression system in the event of a fire, rather than waiting for the temperature sensitive tubing to burst.

In order to be effective in extinguishing a fire, the fire suppression system must be operated at a sufficiently high pressure to release water from the showerhead system, for example, by a sufficiently high volume rate. Furthermore, when powders or foams are used as fire extinguishing materials, in order to release a sufficient volume of powder or foam at the fire source over a given period of time, the fire extinguishing system must be operated at high pressure, for example at a gauge pressure of 20 to 200 bar, 20 to 150 bar, 20 to 100 bar, 25 to 75 bar, 25 to 65 bar, 25 to 60 bar, 25 to 40 bar.

The present invention seeks to solve the aforementioned problems.

WO 2018/185484 (Reacton Fire Suppression Limited) discloses an automatic valve comprising a body configured to axially receive a piston therein, the piston being movable within the body between a first axial position in which the piston is configured to seal a valve opening when pneumatic pressure is applied to the piston, and a second axial position in which the piston is configured to withdraw from the valve opening such that fire suppressant may enter the valve body through the valve opening, wherein the piston comprises a passage longitudinally therethrough and a check valve positioned within the passage such that fluid may enter the check valve in a first longitudinal direction but not in a second longitudinal direction.

Disclosure of Invention

In a first aspect of the invention, there is provided a pneumatic valve for a fire suppression system, the pneumatic valve comprising a body, a piston and an integrated plug valve,

the body is configured to axially receive a piston therein,

the piston being movable within the body between a first axial position in which the piston is configured to seal the valve opening when pneumatic pressure provided by the non-combustible gas is applied to the piston, and a second axial position in which the piston is configured to withdraw from the valve opening such that pressurized fire suppression material may enter the body through the valve opening,

wherein the piston comprises machined flanges defining a volume for non-combustible gas and a volume for pressurized fire extinguishing material, respectively, separated by the machined flanges,

the integrated tap valve is configured to control the application and release of pneumatic pressure and indirectly control the discharge of fire extinguishing material,

wherein the plug valve comprises a rotatable plug comprising: a valve stem having a transverse bore for passing non-combustible gas therethrough; a blind bore in the body configured to receive a valve stem; and a valve stem seal between the valve stem and the blind bore, the valve stem seal providing a fluid seal between the valve stem and the blind bore, thereby preventing a reduction in pneumatic pressure due to the escape of non-combustible gases between the valve stem and the blind bore, and allowing the valve stem to rotate within the blind bore,

wherein the blind bore includes at least one or two annular groove portions on an inner surface thereof for receiving a portion of a valve stem seal to provide a further fluid seal.

In a second aspect of the present invention, there is provided a fire suppression system comprising: according to the first aspect of the present invention, a pneumatic valve, a detecting device for detecting the presence of fire or abnormal heat, a non-combustible gas source for maintaining the pneumatic valve in a normal operation state, a fire extinguishing material source connected to the pneumatic valve, and a pipe or pipe system for delivering the fire extinguishing material to the fire source,

wherein detection of a fire or abnormal heat by the detection means automatically reduces or eliminates the non-flammable gas pressure in the pneumatic valve, resulting in release of fire extinguishing material from the source of fire extinguishing material to the pneumatic valve and thus delivery of fire extinguishing material to the source of fire or heat via the pipe or pipe system.

In a third aspect of the present invention there is provided a method of operating a fire suppression system comprising the steps of providing a fire suppression system comprising a pneumatic valve according to the first aspect of the present invention, a temperature sensitive detection device to detect the presence of a fire or abnormal heat, a source of non-combustible gas to maintain the pneumatic valve in a normal operating condition, a source of fire suppression material connected to the pneumatic valve, and a conduit or piping system to deliver fire suppression material to the source of fire,

wherein detection of a fire or abnormal heat by the temperature sensitive detection means automatically reduces or eliminates the non-flammable gas pressure in the pneumatic valve via the inflation port, resulting in release of fire extinguishing material from the source of fire extinguishing material to the pneumatic valve, and thus delivery of fire extinguishing material to the fire source or sources via the pipe or pipe system,

wherein the method comprises the further step of adjusting the position of the rotatable plug, thereby controlling the loss rate of the non-combustible gas, and delaying the release of the fire extinguishing material from the source of fire extinguishing material to the pneumatic valve and thereby delivering the fire extinguishing material to the fire source or heat source via the pipe or pipe system.

Drawings

The invention will be described in more detail with reference to the following drawings, in which:

FIGS. 1a and 1b are external side views of one embodiment of a pneumatic valve of the present invention, the difference between FIG. 1a and FIG. 1b being that the pneumatic valve is rotated 90 degrees about a longitudinal axis;

FIGS. 2a and 2b are longitudinal cross-sectional views taken along lines D-D and 1b and E-E of the embodiment of the pneumatic valve of the present invention shown in FIGS. 1a and 1b, respectively;

FIGS. 3a and 3b are an external side view and a longitudinal cross-sectional view, taken along line F-F of FIG. 3a, of a plug (which is within the pneumatic valve of the present invention shown in FIGS. 1a and 1 b), respectively; and is also provided with

Fig. 4a to 4d are respectively an exploded view of a plug valve (which is located in the pneumatic valve of the present invention shown in fig. 1a and 1 b), a plan view of a stop washer in a state in which a plug of the plug valve according to fig. 4a is in place, an external side view of the pneumatic valve of the present invention according to fig. 1b, and an enlarged section taken along line H-H of fig. 4 c.

Detailed Description

the body is configured to axially receive a piston therein,

wherein the piston comprises a machined flange defining a volume for non-combustible gas and a volume of pressurized fire extinguishing material, respectively, separated by the machined flange,

wherein the plug valve comprises a rotatable plug comprising: a valve stem having a transverse bore for passing non-combustible gas therethrough; a blind bore in the body configured to receive a valve stem; and a stem seal between the valve stem and the blind bore, the stem seal providing a fluid seal between the valve stem and the blind bore, thereby preventing a reduction in pneumatic pressure due to the escape of non-combustible gases between the valve stem and the blind bore, and allowing the valve stem to rotate within the blind bore,

Preferably, the valve stem seal is formed from Polytetrafluoroethylene (PTFE). The plug valve optionally includes at least one O-ring seal that provides a fluid seal between the plug and a retaining nut for retaining the plug within the blind bore, preferably the plug valve includes two O-ring seals.

The plug valve optionally further comprises a stop washer, wherein the stop washer comprises an inner edge that is partially flat and partially curved adapted to cooperatively interact with a corresponding partially flat and partially curved waist of the plug such that the plug rotates between two stop positions, wherein the stop washer further comprises a circumferential protrusion for preventing co-rotation of the plug and the stop washer combination beyond the two end stop positions, the circumferential protrusion being configured to lock into a recess on the exterior of the body.

The pneumatic valve optionally further comprises a first hollow body portion and a second hollow body portion, wherein the second hollow body portion houses the piston, wherein a fluid seal is achieved between the first hollow body portion and the second hollow body portion by a threaded fit comprising a male thread on the first hollow body portion and a female thread on the second hollow body portion, the second hollow body portion further comprising a first annular shoulder and a second annular shoulder, and a first O-ring seal and a second O-ring seal disposed between the first hollow body portion and the second hollow body portion, the first O-ring seal and the second O-ring seal mating at the first annular shoulder and the second annular shoulder.

The pneumatic valve optionally further comprises an inflation port for pressurizing the pneumatic valve and for fitting a thermally sensitive burst tube or tubing or sensor operated vent (where the sensor may detect a fire),

wherein the inflation port communicates with the volume of non-combustible gas fluid via an inflation channel,

wherein the plug valve controls the passage of non-combustible gas through the inflation channel, wherein the pneumatic valve further comprises at least one pressurized material port for a conduit or piping system for delivering fire extinguishing material to a fire source,

wherein the pneumatic valve optionally further comprises at least one gas port for a heat sensitive burst pipe or tubing or a sensor operated vent, wherein the sensor can detect a fire, the gas port being in fluid communication with the volume of non-flammable gas.

The plug valve optionally includes a stop washer that cooperates with the plug to limit rotation of the stop washer and plug between two stop positions, the stop washer including a circumferential projection for preventing co-rotation of the stop washer and plug, the circumferential projection being adapted to lock into a recess on the outside of the body.

In one embodiment of the invention, the piston may include a primary cylindrical shaft and a secondary cylindrical shaft separated by a machined flange including first and second planar surfaces and an annular recess configured to receive a first piston seal for providing a seal between the machined flange and the second hollow body portion,

wherein the piston further comprises a second piston seal disposed on the main cylindrical shaft, the second piston seal providing a seal between the main cylindrical shaft and a fourth annular shoulder of the second hollow body portion positioned toward the valve opening when the piston is in the first axial position,

wherein the piston further comprises a third piston seal on or about the secondary cylindrical shaft, the third piston seal providing a seal between the secondary cylindrical shaft and the first hollow body portion when the piston is in the second axial position,

wherein the piston further comprises a fourth piston seal disposed at the junction between the main cylindrical shaft and the machined flange, the fourth piston seal providing a seal between the junction and the third annular shoulder of the second hollow body portion when the piston is in the first axial position.

In one embodiment of the invention, the piston may further comprise a longitudinal axial passage for pressurizing the fire suppressing material, and optionally a one-way check valve within the longitudinal axial passage, which enables fluid to pass through unimpeded in only one direction towards the valve opening, and enables fluid to return through the check valve only if the fluid pressure differential on either side of the check valve exceeds a predetermined pressure differential. Once inflated, only a small trickle of non-combustible gas may be returned from the volume for pressurized fire suppression material through the longitudinal axial passage and check valve to compensate for any loss of non-combustible gas from the volume for non-combustible gas through, for example, a thermally sensitive burst tube or piping system or a sensor operated vent where the sensor may detect a fire or heat. The check valve also effectively prevents any fire suppressing material from contaminating the volume for the non-flammable gas and thus contaminating the heat sensitive burst pipe or piping system or the sensor operated exhaust port (where the sensor can detect fire or heat).

In a preferred embodiment of the invention, at least one of the first and second O-ring seals and/or the second, third and fourth piston seals is provided in an annular corner recess, thereby providing an improved seal compared to a seal provided between two flat surfaces.

In another embodiment, the pneumatic valve further comprises a bursting plug in fluid communication with the pressurized fire suppression material via a bursting plug passageway.

Pneumatic valves typically have operating pressures in the range of 20 to 200 bar, 20 to 150 bar, 20 to 100 bar, 25 to 75 bar, 25 to 65 bar, 25 to 60 bar, 25 to 40 bar gauge.

The detection means may be sensitive to heat or smoke.

In one embodiment, the fire suppression system of the present invention provides at least two pneumatic valves, each in series fluid communication with a source of fire suppression material, wherein removal of the non-flammable gas pressure in one pneumatic valve results in a reduction or elimination of the non-flammable gas pressure in all pneumatic valves.

Fig. 1a shows a side view of one embodiment of the pneumatic valve of the present invention, comprising a body (109) comprising a first hollow body portion (101) and a second hollow body portion (102). The first hollow body portion comprises gas ports (103) on the left as well as on the front side, which are adapted for use, for example, with heat sensitive burst pipes or pipe systems or sensor operated exhaust ports as part of a fire detection and extinguishing system, wherein the sensor may detect a fire or heat by e.g. heat or smoke detection. The first hollow body portion is not limited to two gas ports. Indeed, the first hollow body portion need not necessarily include any gas ports. The upper limit of the number of gas ports is limited only by the size of the gas ports relative to the size of the first hollow body portion, but is typically two to four. The first hollow body portion further comprises an inflation port (108) on the upper right side for pressurizing the pneumatic valve and optionally for assembly of a heat sensitive burst tube or tubing system or a sensor operated vent where the sensor may detect fire or heat.

Fig. 1a also shows an integrated stopcock (104) located on the lower right side of the upper hollow body portion and directly below the inflation port. Although the plug valve is not necessarily located directly below the inflation port, this location is a preferred location for ease of manufacture.

The second hollow body portion in fig. 1a comprises pressure material ports (105) on the left, right and front sides, which are adapted for use, for example, with a pipe or pipe system for delivering fire extinguishing material to a fire source as part of a fire detection and extinguishing system. The material is typically a fire extinguishing material such as water, carbon dioxide or other gas, a suitable foam or powder based material, all under pressure and well known to those skilled in the art. Preferably, the fire extinguishing material is in the form of a liquid or powder. The second hollow body portion must include at least one pressurized material port. The upper limit of the number of pressurized material ports is limited only by the size of the pressurized material ports relative to the size of the second hollow body portion, but is typically two to four.

As shown in fig. 1a, at the bottom of the second hollow body portion is a valve opening (106) that provides fluid communication between the second hollow body portion and a source of pressurized material (not shown), typically a pressurized cartridge of material.

Fig. 1b shows a side view of the embodiment of the pneumatic valve of the present invention of fig. 1a rotated 90 degrees about the longitudinal axis (clockwise when viewed from above) with respect to fig. 1a, thus illustrating many of the same features as fig. 1 a. Fig. 1b also shows a bursting plug (107) at the right side of the second hollow body portion.

FIG. 2a shows a longitudinal cross-sectional view of the embodiment of the pneumatic valve of the present invention shown in FIG. 1a, taken along line D-D of FIG. 1 a. Fig. 2a shows an integrated pressure gauge (201) fitted in the top hole of the first hollow body part, which is in fluid communication with a central cavity (203) in the second hollow body part via a central channel (202) within the first hollow body part. Figure 2a also shows a gas port on the left side of the first hollow body portion, which (like all gas ports) is also in fluid communication with the central cavity in the second hollow body portion via a central passage within the first hollow body portion.

Fig. 2a also shows a piston (204) that can move freely up and down in the central channel along the vertical axis of the piston. The piston includes a longitudinal axial passage (205) therethrough, and optionally a one-way check valve (206) positioned within the longitudinal axial passage (205). The pressurized material ports (as with all pressurized material ports) on the left side of the second hollow body portion are in fluid communication with a source of pressurized material via a central cavity in the second hollow body portion when the passageway is not blocked by the piston. The bursting plug (107) on the right side of the second hollow body portion is in fluid communication with a source of pressurized material via two bursting plug passageways (not shown). If the pressure of the material exceeds a predetermined safety level, the pressure is automatically released by the burst plug.

Fig. 2a shows the integrated pressure gauge engaged with the top hole of the first hollow body portion by a threaded fit via a male thread on the integrated pressure gauge and a female thread in the top hole of the first hollow body portion, wherein two O-ring seals (207, 208) are located at different interfaces between the pressure gauge underside and the top surface of the first hollow body portion to provide a fluid seal. Fig. 2a also shows that a fluid seal is achieved between the first hollow body portion and the second hollow body portion by a threaded engagement via a male thread on the underside of the first hollow body portion and a female thread in the top bore of the second hollow body portion, wherein the first and second O-ring seals (209, 210) are located at different interfaces between the underside of the first hollow body portion and the first surface of the second hollow body portion. In particular, the second hollow body portion has first and second annular shoulders (213, 214) towards the top of the second hollow body portion, and first and second O-ring seals are disposed between the first and second hollow body portions, wherein the first and second O-ring seals mate at the first and second annular shoulders.

Fig. 2a also shows that a fluid seal is achieved between the second hollow body portion and the source of pressurized material by a threaded engagement via a male thread on the underside of the second hollow body portion and a female thread in the top bore of the container (not shown) containing pressurized material, wherein a third O-ring seal (211) is located at the interface between the underside of the second hollow body portion, the male thread, and the upper surface of the container containing pressurized material.

Fig. 3a shows an external side view of the piston, and fig. 3b is a longitudinal section taken along line F-F of fig. 3 a. Referring to fig. 3b, the piston comprises a primary cylindrical shaft (301) and a secondary cylindrical shaft (302) separated by a machined flange (303) comprising first and second planar surfaces (304, 305) and an annular recess (306) configured to receive a first piston seal (307) for providing a seal between the machined flange and the second hollow body portion.

Fig. 3b also shows a longitudinal axial passage (205) capable of pressurizing the material source, and a one-way check valve (206). The diameter of the longitudinal axial passage is between 0.5mm and 2 mm. In one embodiment, the piston does not include a one-way check valve, in which case the longitudinal axial passage has a diameter of less than 0.5mm. The longitudinal passageway has a bottom end that is larger in diameter than the remainder of the longitudinal passageway and the check valve is located within the bottom end.

The check valve (206) operates to enable fluid (i.e., liquid or gas) to pass through the check valve unimpeded in only one direction toward the valve opening (106). The check valve has an inlet and an outlet that can be operated automatically without any manual intervention. If the fluid pressure differential exceeds a predetermined pressure differential or cracking pressure to cause the inlet and/or outlet to open, fluid may be returned through the check valve.

The piston further comprises a second piston seal (308) provided on the main cylindrical shaft, which second piston seal provides a seal between the main cylindrical shaft and a fourth annular shoulder of the second hollow body portion located towards the valve opening (106) when the piston is in the first axial position, i.e. when the piston seals the valve opening (106).

The piston further comprises a third piston seal (309) on or around the secondary cylindrical shaft, which third piston seal provides a seal between the secondary cylindrical shaft and the first hollow body portion when the piston is in the second axial position, i.e. when the piston has been withdrawn from the valve opening (106).

The piston further includes a fourth piston seal (310) disposed at the junction between the main cylindrical shaft and the machined flange and providing a seal between the junction and a third annular shoulder (212) of the second hollow body portion when the piston is in the first axial position.

Optionally, the first, second and third O-ring seals (209, 210, 211) and the second, third and fourth piston seals (308, 309, 310) are disposed in annular recesses in an outside corner or an inside corner of one of the opposing interfaces, thereby providing an improved seal compared to a seal disposed between two flat surfaces. Without being bound by theory, it is believed that the improvement in sealing is due to the formation of more than one interface between the compression seal and the recess.

Turning now to fig. 2b, there is shown a longitudinal cross-sectional view of the embodiment of the pneumatic valve of the present invention shown in fig. 1b, taken along line E-E of fig. 1 b. The figure shows that the inflation port (108) is in fluid communication with a central cavity within the second hollow body portion via an inflation channel (215). Fig. 2b shows the plug valve (104) controlling the flow of gas through the inflation channel.

Fig. 4a is an exploded view of the plug valve (104). The plug valve includes a plug (401), first and second plug valve O-ring seals (406, 407), and a stop washer (409).

The plug includes a valve stem (415) at one end that includes a transverse bore (402) that can be aligned with the inflation channel, thereby completing fluid communication between the inflation port and the central cavity. The plug further comprises: a slot (403) for a flat head screwdriver bit at the end remote from the valve stem, which allows the plug to be rotated from outside the pneumatic valve; and first and second annular groove portions (404, 405) for first and second plug valve O-ring seals (406, 407); and a partially flat and partially curved waist (408) positioned between the slot and the valve stem and closest to the valve stem, the waist interacting rotationally and cooperatively with the inner edge of the stop washer (409) between two end stop positions separated by about 90 degrees. The two stop positions correspond to the following positions: a position when the transverse bore (402) is aligned with the inflation channel to establish fluid communication between the inflation port and the central cavity, and a position when the transverse bore (402) is substantially at right angles to the inflation channel to block fluid communication between the inflation port and the central cavity.

The stop washer further comprises a circumferential projection (410) which locks into a recess on the exterior of the first hollow body portion (101) to prevent co-rotation of the combination of the plug and the stop washer which would result in rotation of the plug beyond the two end stop positions. One technical advantage of the ability of the projection to lock into a recess on the exterior of the first hollow body portion is that the pneumatic valve of the present invention is more compact in appearance than those valves having externally mounted balls or other functionally equivalent valves.

Fig. 4a also shows that the plug valve comprises a Polytetrafluoroethylene (PTFE) washer (411) for smoothing axial rotation between the plug and the stop washer.

The plug valve further includes a PTFE valve stem sleeve (412) and a blind bore (416) in the first hollow body portion, the blind bore adapted to receive the plug and the valve stem sleeve, the valve stem sleeve providing a fluid tight seal between the valve stem and the blind bore, thereby preventing loss of fluid from the first hollow body portion through the blind bore while allowing the valve stem to rotate within the blind bore. The plug valve further includes a retention nut (417) for retaining the plug (401) within the blind bore (416).

The first and second plug valve O-ring seals (406, 407) provide a fluid seal between the plug (401) and the retention nut (417).

Fig. 4b is a plan view of the stop washer with the plug in place. The inner edge of the stop washer is a partially flat and partially curved edge which co-operatively interacts with a corresponding rotating partially flat and partially curved waist (408) of the plug in such a way that the plug rotates between two stop positions separated by about 90 degrees.

Fig. 4c is a side view of the pneumatic valve according to the present invention of fig. 1b, and fig. 4d is an enlarged cross-sectional view taken along line H-H of fig. 4 c. Fig. 4d shows a pair of annular groove portions (413, 414) in the inner wall of the blind hole 416. A valve stem sleeve is located between the valve stem and an inner wall of the blind bore, and a portion of the valve stem sleeve is received in the pair of annular groove portions, thereby enhancing fluid tightness.

The pneumatic valve of the present invention is typically made of stainless steel, particularly grade 303 stainless steel, except for the seals. Unless otherwise specified, seals are typically made of rubber, such as styrene-butadiene rubber, polyisoprene, chloroprene, nitrile rubber, ethylene Propylene Diene Monomer (EPDM), viton ^TM Fluoroelastomers, butyl rubber, silicone rubber, chlorosulfonated polyethylene, and thermoplastic elastomers.

The pneumatic valve of the present invention is typically operated in a pressure range having a gauge pressure of 20 to 200 bar, 20 to 150 bar, 20 to 100 bar, 25 to 75 bar, 25 to 65 bar, 25 to 60 bar, 25 to 40 bar.

The cartridge is filled with fire extinguishing material when used as part of e.g. a fire extinguishing system and is fitted with a pneumatic valve according to the invention. The pneumatic valve optionally includes a siphon tube protruding from a valve opening (106) at the bottom of the second hollow body portion (102) and inserted through the nozzle. The lower end of the siphon tube rests near the bottom of the barrel. The siphon ensures an efficient discharge of the extinguishing material through the pneumatic valve.

After the valve is assembled to the filled cartridge, the pressurized material port is then connected to a pipe or tubing carrying the fire suppressing material and the gas port is connected to a heat sensitive burst pipe or tubing system or a sensor operated vent where the sensor can detect fire or heat. The plug valve (104) is opened and then a non-combustible gas is filled from the inflation port (108) into the central cavity (203) via the inflation channel (215), forcing the piston to a first axial position in which a second piston seal (308) disposed on the main cylindrical shaft provides a seal between the main cylindrical shaft and a fourth annular shoulder of the second hollow body portion positioned towards the valve opening (106), and a fourth piston seal (310) disposed at a junction between the main cylindrical shaft and the machined flange provides a seal between the junction and a third annular shoulder (212) of the second hollow body portion.

The non-combustible gas then passes through both the longitudinal axial passage (205) and the check valve (206) simultaneously into the cartridge containing the pressurized fire suppressing material and via the central passage (202) into the thermally sensitive burst tube or tubing or sensor operated vent where the sensor can detect fire or heat so that the pressure on both sides of the piston is equalized. The charging of non-combustible gas is then terminated by closing the plug valve (104).

Once inflated, only a small thin stream of non-combustible gas may return through the longitudinal axial passage (205) and check valve (206) from the cartridge containing the fire suppressing material and into the central cavity (203) of the second hollow body portion to compensate for any loss of non-combustible gas through the thermally sensitive burst tube or tube system or sensor operated exhaust port where the sensor may detect fire or heat. The check valve is effective to prevent any fire extinguishing material from contaminating the heat sensitive burst pipe or tubing, the sensor operated exhaust port (where the sensor can detect fire or heat), or the central passage (202).

When a fire breaks a portion of the thermally sensitive broken conduit or piping system or triggers a sensor operated vent where the sensor can detect fire or heat, the non-flammable gas pressure in the central passageway (202) and the central cavity (203) of the second hollow body portion is reduced, allowing the piston to rise to a second axial position where a third piston seal (309) on or around the secondary cylinder shaft provides a seal between the secondary cylinder shaft and the first hollow body portion. When the piston rises, fluid communication is established between the pressurized material port and the pressurized fire extinguishing material cylinder, allowing the fire extinguishing material to pass upwardly through the siphon and out through the pressurized material port and the conduit or piping for delivering the fire extinguishing material to the fire source.

When the inflation port (108) is fluidly connected to a heat sensitive conduit or piping system or sensor operated vent where the sensor can detect fire or heat and the aforementioned heat sensitive conduit or piping system bursts or triggers the sensor operated gas vent, the reduction in gas pressure in the central passage (202) and central chamber (203) and thus the delay in releasing the fire suppressing material from the cartridge can be controlled by adjusting the position of the valve stem (401) of the stopcock (104) to change the rate at which non-combustible gas can pass through the transverse bore (402). Proper adjustment of the valve stem (401) may delay the release of fire suppression material from the cartridge for 1 second to 20 seconds. One advantage of delayed release of fire suppression material is in combination with an alarm system to allow safe evacuation of the area surrounding the fire source prior to release of the fire suppression material.

In one embodiment of the invention, the combination of the cartridge and the pneumatic valve may be arranged in series via the gas port. Alternatively, each cartridge and pneumatic valve combination may be fitted with a heat sensitive conduit or piping system or sensor operated vent to each inflation port (108) and the position of the valve stem (401) of each plug valve (104) adjusted to release fire suppressant material from the cartridge at different times.

Claims

1. A pneumatic valve for a fire suppression system, the pneumatic valve comprising a body (109), a piston (204) and an integrated plug valve (104),

the body is configured to axially receive the piston therein,

the piston being movable within the body between a first axial position in which the piston is configured to seal a valve opening (106) when pneumatic pressure provided by non-combustible gas is applied to the piston, and a second axial position in which the piston is configured to withdraw from the valve opening such that pressurized fire suppression material can enter the body through the valve opening,

wherein the piston comprises a machined flange (303) defining a volume for non-combustible gas and a volume for pressurized fire extinguishing material, respectively, separated by the machined flange,

the integrated tap valve is configured to control the application and release of the pneumatic pressure and indirectly control the discharge of the fire suppressing material,

wherein the plug valve comprises a rotatable plug (401) comprising: a valve stem (415) having a transverse bore (402) for passing the non-combustible gas; a blind hole (416) in the body configured to receive the valve stem; and a valve stem seal (412) between the valve stem and the blind bore, the valve stem seal providing a fluid seal between the valve stem and the blind bore, thereby preventing the pneumatic pressure from being reduced due to escape of the non-combustible gas between the valve stem and the blind bore, and allowing the valve stem to rotate within the blind bore,

wherein the blind bore includes at least one or two annular groove portions (413, 414) on an inner surface thereof for receiving a portion of the valve stem seal to provide a further fluid seal.

2. A pneumatic valve for a fire suppression system as recited in claim 1, wherein the valve stem seal is formed of Polytetrafluoroethylene (PTFE).

3. A pneumatic valve for a fire suppression system according to claim 1 or 2, said plug valve comprising at least one O-ring seal (406, 407) providing a fluid seal between the plug and a retaining nut (417) for retaining the plug within the blind bore, preferably the plug valve comprises two O-ring seals.

4. A pneumatic valve for a fire suppression system according to any one of the preceding claims, wherein the plug valve comprises a stop washer (409),

wherein the stop washer comprises an inner edge which is partially flat and partially curved adapted to co-operatively interact with a corresponding partially flat and partially curved waist (408) of the plug such that the plug rotates between two stop positions,

wherein the stop washer further comprises a circumferential protrusion (410) for preventing co-rotation of the combination of the plug and the stop washer beyond the two end stop positions, the circumferential protrusion being configured to lock into a recess on the exterior of the body.

5. A pneumatic valve for a fire suppression system according to any one of the preceding claims, wherein the pneumatic valve further comprises a first hollow body portion (101) and a second hollow body portion (102),

wherein the second hollow body portion accommodates the piston,

wherein a fluid seal is achieved between the first hollow body portion and the second hollow body portion by a threaded fit comprising a male thread on the first hollow body portion and a female thread on the second hollow body portion, the second hollow body portion further comprising first and second annular shoulders (213, 214), and first and second O-ring seals (209, 210) arranged between the first and second hollow body portions, the first and second O-ring seals fitting at the first and second annular shoulders.

6. A pneumatic valve for a fire suppression system according to any one of the preceding claims, wherein the pneumatic valve further comprises an inflation port (108) for pressurizing the pneumatic valve and for fitting a thermally sensitive burst tube or tubing or a sensor operated vent, wherein a sensor is capable of detecting a fire,

wherein the inflation port is in fluid communication with the volume for non-combustible gas via an inflation channel (215),

wherein the plug valve controls the non-combustible gas to pass through the gas charging channel,

wherein the pneumatic valve further comprises at least one pressurized material port (105) for a pipe or pipe system for delivering fire extinguishing material to a fire source,

wherein the pneumatic valve optionally further comprises at least one gas port (103) for a thermally sensitive burst pipe or tubing system or a sensor operated exhaust port, wherein the sensor is capable of detecting a fire, said gas port being in fluid communication with the volume for non-combustible gas.

7. A pneumatic valve for a fire extinguishing system according to any of the preceding claims, wherein the plug valve comprises a stop washer (409) cooperating with the plug to limit the rotation of the stop washer and the plug between two stop positions, the stop washer comprising a circumferential protrusion (410) for preventing the stop washer and the plug from co-rotating, the circumferential protrusion being adapted to lock into a recess on the outside of the body (109).

8. A pneumatic valve for a fire suppression system according to claim 5 and any one of claims 6 or 7 when dependent on claim 5, wherein the piston (204) comprises a primary cylindrical shaft (301) and a secondary cylindrical shaft (302) separated by a machined flange (303) comprising a first planar face (304), a second planar face (305) and an annular recess (306) configured to receive a first piston seal (307) for providing a seal between the machined flange and the second hollow body portion,

wherein the piston further comprises a second piston seal (308) disposed on the main cylindrical shaft, the second piston seal providing a seal between the main cylindrical shaft and a fourth annular shoulder of the second hollow body portion positioned toward the valve opening (106) when the piston is in the first axial position,

wherein the piston further comprises a third piston seal (309) on or around the secondary cylindrical shaft, the third piston seal providing a seal between the secondary cylindrical shaft and the first hollow body portion when the piston is in the second axial position,

wherein the piston further comprises a fourth piston seal (310) disposed at a junction between the main cylindrical shaft and the machined flange, the fourth piston seal providing a seal between the junction and a third annular shoulder (212) of the second hollow body portion when the piston is in the first axial position.

9. A pneumatic valve for a fire suppression system according to any one of the preceding claims, wherein the piston (204) comprises a longitudinal axial passage (205) for pressurizing the fire suppression material, and optionally a one-way check valve (206) within the longitudinal axial passage, the one-way check valve being capable of passing fluid through the valve in only one direction towards the valve opening without obstruction, and of returning the fluid through the check valve only if the fluid pressure differential on either side of the check valve exceeds a predetermined pressure differential.

10. The pneumatic valve for a fire suppression system according to any one of claims 5 to 9, wherein at least one of the first and second O-ring seals (209, 210) is disposed in an annular corner recess, and/or the pneumatic valve according to claim 8 or claim 9, wherein at least one of the second, third and fourth piston seals (308, 309, 310) is disposed in an annular corner recess.

11. A pneumatic valve for a fire suppression system according to any one of the preceding claims, wherein the pneumatic valve further comprises a bursting plug (107) in fluid communication with the pressurized fire suppression material via a bursting plug passageway.

12. A pneumatic valve for a fire suppression system according to any one of the preceding claims, wherein the pneumatic valve has an operating pressure in the range of 20 to 200 bar, 20 to 150 bar, 20 to 100 bar, 25 to 75 bar, 25 to 65 bar, 25 to 60 bar, 25 to 40 bar gauge.

13. A fire suppression system, the fire suppression system comprising: the pneumatic valve of any one of the preceding claims, a detection device to detect the presence of a fire or abnormal heat, a non-combustible gas source to maintain the pneumatic valve in a normal operating condition, a source of fire suppressing material connected to the pneumatic valve, and a pipe or pipe system to deliver fire suppressing material to the source of fire,

wherein detection of a fire or abnormal heat by the detection means automatically reduces or eliminates the non-flammable gas pressure in the pneumatic valve, thereby causing the fire extinguishing material to be released from the fire extinguishing material source to the pneumatic valve and thereby delivering the fire extinguishing material to the fire source or heat source via the pipe or pipe system.

14. The fire suppression system of claim 13, comprising at least two pneumatic valves, each in series fluid communication with a source of fire suppression material, wherein removal of non-flammable gas pressure in one pneumatic valve results in a reduction or elimination of non-flammable gas pressure in all of the pneumatic valves.

15. A method of operating a fire suppression system, the method comprising the step of providing a fire suppression system comprising a pneumatic valve according to any one of claims 6 to 12, a detection device to detect the presence of a fire or abnormal heat, a non-combustible gas source to maintain the pneumatic valve in a normal operating state, a source of fire suppression material connected to the pneumatic valve, and a pipe or pipe system to deliver fire suppression material to the source of fire,

wherein detection of a fire or abnormal heat by the detection means automatically reduces or eliminates the non-flammable gas pressure in the pneumatic valve via the inflation port (108), thereby causing the fire extinguishing material to be released from the fire extinguishing material source to the pneumatic valve and thereby delivering the fire extinguishing material to the fire or heat source via the pipe or pipe system,

wherein the method comprises the further step of adjusting the position of the rotatable plug (401) so as to control the loss rate of the non-combustible gas and delay the release of the fire extinguishing material from the source of fire extinguishing material to the pneumatic valve and thereby deliver the fire extinguishing material to the source of fire or heat via the pipe or pipe system.