Patent Description:
This relates to the field of relief devices, and in particular, to a pressure relief apparatus that vents a tank upon detection of a temperature at or above a temperature threshold or in response to pressurization of a compartment of the pressure relief apparatus at or above a predetermined pressure threshold.

Pressurized fluids are typically stored in pressure vessels. These vessels may be constructed of materials that can withstand the internal pressure of the vessel, but may degrade if exposed to external elements, such as a fire. If exposed to a fire, the pressure inside the vessel may increase, while the material of the vessel may weaken, causing the vessel to rupture and exposing the pressurized fluids to the fire.

A relief device may be installed on a vessel to mitigate rupture. The relief device may detect a relief condition, such as temperature, at or above a threshold. Upon detection of the relief condition, the relief device may vent the tank in a controlled manner before the tank ruptures. The relief device may empty the vessel faster than the vessel's degradation so the vessel may be safely vented.

To increase storage capacity, multiple pressure vessels may be connected together in fluid communication. In such a multi-vessel system, a plurality of relief devices may be installed, for example, one relief device on each vessel, to safely vent the pressurized fluid. However, the external element, such as the fire, may only affect one vessel, or may affect one vessel for an extended period of time before affecting the other vessels. In such a situation, the relief device of that one vessel may activate and vent the vessel. However, because the vessels are in fluid communication, the pressurized fluid of the unaffected vessels may flow into the affected vessel, essentially refilling the affected vessel while it is being vented. This may increase the amount of time required to vent the vessel, or the vessel may be refilled faster than it is being vented, resulting in vessel rupture and exposure of the pressurized fluid to the fire.

One way to protect multi-vessel systems may be to use multiple relief devices to activate a single valve, such as a piloted valve. Unfortunately, this configuration may not be effective with smaller vessels. Further, it may require connections between the vessels and the single valve that must be kept free of impediments, which may not be practical.

<CIT> discloses a valve apparatus including a body, a closure member, upstream and downstream compartments a closure member passage, a first fluid pressure-receiving surface fraction and a second fluid pressure-receiving surface fraction. The body includes an inlet port, a first outlet port, and a second outlet port, and a fluid passage network extending between the inlet port and the first and second outlet ports. The closure member is configured for movement between an open position and a closed position, wherein, in the open position, the first outlet port is open, and wherein, in the closed position, the first outlet port is closed.

The invention is defined by a method of controlling pressure in a tank according to claim <NUM> and a vent system for controlling pressure of a pressurized system according to claim <NUM>.

In one aspect, there is provided an example pressure relief apparatus for venting a tank comprising: an inlet port, an outlet port, a closure member retained, relative to the inlet and outlet ports, for preventing, or substantially preventing, fluid communication between the inlet port and the outlet port, a trigger mechanism including a temperature response portion, and a compartment for receiving pressurized fluid from the outlet port and communicating the received pressurized fluid to the trigger mechanism. The trigger mechanism and the closure member are cooperatively configured such that the closure member becomes released from retention and moveable for effecting establishment of fluid communication between the inlet port and the outlet port in response to receiving of heat energy by the temperature responsive portion. Further, the trigger mechanism, the closure member, and the compartment are cooperatively configured such that the closure member becomes released from retention and moveable for effecting establishment of fluid communication between the inlet port and the outlet port in response to the communication of the pressurized fluid to the trigger mechanism via the compartment.

In another aspect, there is provided an example method of controlling pressure in a tank comprising: receiving a flow of pressurized fluid from an external pressurized fluid source into a compartment defined in a pressure relief apparatus of a tank, and opening the pressure relief apparatus in response to the receiving of the flow of pressurized fluid such that the tank is vented.

In another aspect, there is provided an example vent system for controlling pressure of a pressurized system, the pressurized system comprising a first tank and a second tank, the vent system comprising: the first tank in fluid communication with a first relief apparatus, the first relief apparatus comprising an inlet port and an outlet port, and the second tank in fluid communication with a second relief apparatus, the second relief apparatus comprising an inlet port and an outlet port, the outlet port of the first relief apparatus in fluid communication with the outlet port of the second relief apparatus. The second relief apparatus is configured to be triggered for venting the second tank in response to receiving gaseous material vented from the first tank. Other aspects will be apparent from the description and drawings provided herein.

In the figures which illustrate example embodiments,.

A pressure relief apparatus for venting a tank, a method for controlling pressure in a tank, and a vent system for controlling pressure of a pressurized system are disclosed. The pressure relief apparatus can be triggered to vent the tank either upon detection of a temperature at or above a predetermined temperature threshold, or upon pressurization of a compartment at or above a predetermined pressure threshold. The pressure of a tank can be controlled by receiving a flow of pressurized fluid from an external pressurized fluid source into the compartment defined in the pressure relief apparatus of a tank, and opening the pressure relief apparatus in response receiving the flow of pressurized fluid such that the tank is vented. The vent system comprises a first and second tank, each in fluid communication with a relief apparatus. The outlet port of the relief apparatuses are in fluid communication, and one of the relief apparatuses is configured to be triggered for venting in response to venting by the other relief apparatus.

<FIG> depict an example pressure relief apparatus <NUM>, which, in some embodiments, is used to vent a tank. The pressure relief apparatus <NUM> depicted in <FIG> is in closed position.

The pressure relief apparatus <NUM> includes a body <NUM>. The body <NUM> defines an inlet port <NUM>, an outlet port <NUM>, a fluid passage <NUM>, and a receiving passage <NUM>. The inlet port <NUM> is configured to be in fluid communication to a tank <NUM> (not depicted) for receiving the contents from the tank <NUM>. In some embodiments, the contents of the tank <NUM> are pressurized, such as a pressurized gaseous material. The outlet port <NUM> is configured for venting the received contents to the immediate environment (for example, the atmosphere). In some embodiments, the material of the body <NUM> is metallic. Suitable metallic materials include brass, aluminum, or stainless steel, or a combination of these materials.

The pressure relief apparatus <NUM> further includes a closure member <NUM> interposed between the inlet port <NUM> and the outlet port <NUM>, such that when the closure member <NUM> is in the closed position, fluid communication between the inlet port <NUM> and the outlet port <NUM> is sealed or substantially sealed, and in the open position, fluid communication is effected between the inlet port <NUM> and the outlet port <NUM>.

The closure member <NUM> is retained, relative to the inlet port <NUM> and the outlet port <NUM>, for preventing fluid communication between the inlet port <NUM> and the outlet port <NUM>. The closure member <NUM> is moveable between a closed position and an open position within the receiving passage <NUM>. The discharge fluid passage <NUM> extends from the inlet port <NUM> to the outlet port <NUM> for effecting fluid communication between the inlet and outlet ports <NUM>, <NUM>, when the closure member <NUM> is disposed in the open position.

In some embodiments, for example, the closure member <NUM> includes a closure member body 208A, which carries an O-ring 208B for effecting sealing engagement of the closure member <NUM> to the body <NUM>, such that fluid is prevented from flowing from the inlet port <NUM> to the outlet port <NUM> while the closure member <NUM> is disposed in the closed position. The closure member body 208A is made from one or more of a variety of materials including metal. For example, a suitable material is steel. As another example, the O-ring 208B is made from elastomeric material.

The pressure relief apparatus <NUM> further includes a trigger mechanism <NUM> configured to release the closure member <NUM> in response to detection of a relief condition. The trigger mechanism <NUM> is provided for effecting a change in condition to the closure member <NUM>, in response to receiving of a relief condition, such that the closure member <NUM> becomes displaceable from the closed position to the open position. The trigger mechanism <NUM> is disposable from a non-actuating position to an actuating position, in response to the relief condition, with effect that the closure member <NUM> becomes displaceable for effecting fluid communication between the inlet and the outlet ports <NUM>, <NUM>. In some embodiments, for example, the relief condition is a temperature at or above a predetermined temperature threshold, such that the pressure relief apparatus <NUM> is a thermally actuated pressure relief apparatus. Exemplary thermally actuated pressure relief apparatuses are described and illustrated in <CIT>and <CIT>.

In some embodiments, for example, the trigger mechanism comprises a sensor for detecting the relief condition. When the pressure relief apparatus <NUM> is a thermally actuated pressure relief apparatus, in some of these embodiments, for example, the trigger mechanism <NUM> includes a temperature responsive portion 210A. In some embodiments, for example, the temperature responsive portion <NUM> includes a shape memory alloy, and the relief condition is a temperature at or above a predetermined temperature threshold that effects disposition of the temperature responsive portion 210A. In some embodiments, for example, the receiving of heat energy by the temperature responsive portion 210A effects a change in shape of the heated portion of the temperature responsive portion 210A such that a change in dimension of the temperature-responsive portion 210A is effected. In some of these embodiments, for example, the temperature responsive portion 210A includes a longitudinal axis, and the change in shape includes a reduction in length of the temperature responsive portion 210A along its longitudinal axis. In some embodiments, for example, the temperature responsive portion 210A is a condition detecting sensor, the temperature responsive portion 210A including a wire made with the shape memory alloy, which can detect the relief condition. When the wire has a temperature at or above the predetermined temperature threshold, the wire reduces in length along a longitudinal axis of the wire.

In some embodiments, for example, the material or combination of materials used for the temperature responsive portion 210A has a characteristic temperature at which the material or combination of materials changes in shape in response to receiving sufficient heat energy. In some embodiments, for example, this characteristic temperature falls within a range of temperatures. The material or combination of materials that is selected for the temperature responsive portion 210A is based on corresponding the characteristic temperature of the material or materials at which a change in shape is effected with the desired predetermined temperature threshold at which the trigger mechanism of the pressure relief apparatus <NUM> is to release the closure member <NUM>. In some embodiments, for example, the desired predetermined temperature threshold at which the trigger mechanism of the pressure relief apparatus <NUM> is to release the closure member <NUM> is based on the properties of the contents stored in the tank <NUM> that is attached to the pressure relief apparatus <NUM>, such as an autoignition temperature, a flash point, a temperature at which the contents expand or contract, and a temperature at which the contents may undergo a phase change.

The trigger mechanism <NUM> is configured to release the closure member <NUM> when the temperature responsive portion 210A has a temperature at or above the predetermined temperature threshold. A heat source, such as a fire, from which the temperature responsive portion 210A can receive heat energy, and which can effect displacement of the trigger mechanism <NUM>, can also effect heating of the tank <NUM> to which the pressure relief apparatus <NUM> is attached. In such cases, in some embodiments, for example, the displacement of the trigger mechanism <NUM> is effected by the heat before the heating of the tank <NUM> effects the failure of the tank <NUM>, such that the contents within the tank <NUM>, for example, a pressurized gaseous material, is vented remotely from the fire. Failure of the tank <NUM> occurs when the integrity of the tank <NUM> is compromised, such as by, for example, rupturing, breaking or melting. By enabling such venting of the contents within the tank <NUM> before the failure of the tank <NUM>, the risk of explosion, effected by heating of the contents stored within the tank <NUM>, is mitigated.

In addition to including the temperature responsive portion 210A, the trigger mechanism <NUM>, further includes a retainer 210B. The retainer 210B is for effecting retention the closure member <NUM> in the closed position, for preventing displacement of the closure member <NUM> from the closed position to the open position, and for preventing fluid communication between the inlet port <NUM> and the outlet port <NUM>.

The closure member <NUM>, the retainer 210B, and the temperature responsive portion 210A are cooperatively configured such that, while: (i) the closure member <NUM> is disposed in the closed position, (ii) the pressure relief apparatus <NUM> is coupled to the tank <NUM> such that the inlet port <NUM> is disposed in fluid communication with contents within the tank <NUM>, and (iii) the temperature of the temperature responsive portion 210A is disposed below a predetermined temperature threshold, the retainer 210B opposes the force being applied to the closure member <NUM> by the pressure of the pressurized fluid within the tank <NUM> that is urging the displacement of the closure member <NUM> from the closed position to the open position, such that the closure member <NUM> is retained in the closed position by the retainer 210B.

<FIG> depict the pressure relief apparatus <NUM> in closed position. As depicted in <FIG>, the closure member <NUM>, the retainer 210B, and the temperature responsive portion 210A are further cooperatively configured such that, while: (i) the closure member <NUM> is disposed in the closed position, and (ii) the pressure relief apparatus <NUM> is coupled to the tank <NUM> such that the inlet port <NUM> is disposed in fluid communication with the contents within the tank <NUM>, such as pressurized gaseous material, the retainer 210B is displaceable, in response to the temperature responsive portion 210A becoming disposed at a temperature at or above a predetermined temperature threshold, such that the closure member <NUM> becomes released from retention by the retainer 210B and becomes displaceable from the closed position to the open position in response to urging by the contents within the tank <NUM>.

In this respect, in some embodiments, for example, while the trigger mechanism <NUM> is disposed in the actuated position such that the closure member <NUM> is released from retention by the retainer 210B as depicted in <FIG>, the closure member <NUM> is displaceable from the closed position to the open position in response to a sufficient pressure differential being provided between the inlet port <NUM> and the outlet port <NUM> (i.e. while the trigger mechanism <NUM> is disposed in the actuated position, the closure member <NUM> is displaced from the closed position to the open position when the pressure differential between the inlet port <NUM> and the outlet port <NUM> exceeds a predetermined minimum pressure differential). In some of these embodiments, for example, the inlet port <NUM> is disposed in fluid communication with the tank <NUM>, and is, thereby, exposed to fluid pressure within the tank <NUM>, and the outlet port <NUM> is disposed in fluid communication with the atmosphere and is, thereby, exposed to atmospheric pressure, such that, so long as the fluid pressure within the tank <NUM> exceeds atmospheric pressure by a predetermined minimum threshold, and so long as the trigger mechanism <NUM> is disposed in the actuated position, the closure member <NUM> will become displaced from the closed position to the open position. When the closure member <NUM> is displaced from the closed position to the open position, the contents of the tank <NUM> are vented out through the outlet port <NUM>.

In some embodiments, for example, the trigger mechanism <NUM> includes a moveable portion 210C, and an actuator-receiving passage <NUM> is defined within the body <NUM>. As depicted in <FIG> and <FIG>, the moveable portion 210C is displaceable from a non-actuating position to an actuating position, within the actuator-receiving passage <NUM>, in response to the relief condition, with effect that the closure member <NUM> becomes displaceable for effecting fluid communication between the inlet and the outlet ports <NUM>, <NUM>.

In some embodiments, the trigger mechanism <NUM> further includes a fixedly couplable portion 210D. The fixedly couplable portion 210D is configured for being fixed, or substantially fixed, relative to the body <NUM> such that, while the fixedly couplable portion 210D is fixed, or substantially fixed, relative to the body <NUM>, the moveable portion 210C is displaceable relative to the fixedly couplable portion 210D such that the spacing between the moveable portion 210C and the fixedly couplable portion 210D is reduced.

In some embodiments, for example, the fixing, or substantial fixing, of the spatial disposition of the fixedly couplable portion 210D, relative to the body <NUM>, is effected by connection between the body <NUM> and a connector <NUM>, as depicted in <FIG>. For example, the connector <NUM> is made from metallic material, and suitable metallic materials include copper, stainless steel, brass or aluminum, or a combination of said materials. The connector <NUM> is stiffer than the moveable portion 210C of the trigger mechanism <NUM>. In some embodiments, for example, the connector <NUM> is of a tubular form, extending from the body <NUM>, and attached to the trigger mechanism <NUM> with a retaining assembly <NUM>. The retaining assembly <NUM> includes a washer 226A and a crimp 226B. The washer 226A is disposed in an interference relationship with the connector <NUM> such that the washer 226A is fixed, or substantially fixed, relative to the connector <NUM>. The trigger mechanism <NUM> extends through a hole within the washer 226A and its displacement through the hole is restricted by the crimp 226B which is clamped onto an end 210E of the trigger mechanism <NUM>. While the crimp 226B is clamped onto the end 210E of the trigger mechanism <NUM>, the hole of the washer 226A and the crimp 226B are cooperatively configured such that passage of the crimp 226B through the hole, in the direction of the retainer 210B of the trigger mechanism <NUM>, is restricted, with effect that passage of the end 210E of the trigger mechanism <NUM> towards the retainer 210B is restricted and thereby effecting fixing, or substantial fixing, of the end 210E of the trigger mechanism <NUM> relative to the body <NUM>.

In some embodiments, for example, the retaining assembly <NUM> is closed or covered by a cap <NUM> which is connected to the connector <NUM>. Fastening of the connector <NUM> to the retaining assembly <NUM> is then effected with a nut <NUM>, which is threaded to the cap <NUM>, and which forces a ferrule <NUM> to pinch the connector <NUM>. In this respect, during assembly, the nut <NUM> and the ferrule <NUM> are slid over the end of the connector <NUM> which is desired to be fastened to the cap <NUM>. The connector <NUM> is then pushed into an aperture provided within the cap <NUM>. The nut <NUM> is then tightened until the ferrule <NUM> squeezes the connector <NUM>. For example, the cap <NUM> is made using metallic material, such as brass or stainless steel. In some embodiments, for example, the cap <NUM> functions to cover the assembly of the retaining assembly <NUM> to, amongst other things, prevent, or mitigate, material ingress or physical damage.

In some embodiments, for example, the fixing, or substantial fixing, of the spatial disposition of the fixedly couplable portion 210D, relative to the body <NUM>, is effected by an indirect connection to the body <NUM>. In this respect, in some embodiments, for example, the connector <NUM> effects attachment of the fixedly couplable portion 210D to the tank <NUM> to which the body <NUM> is connected. In some of these embodiments, for example, the connector <NUM> is a strap, band or other fastener.

It is understood that a portion of the trigger mechanism <NUM> is not required to be spatially fixed, or substantially fixed, relative to the body <NUM>, in order for the actuation of the closure member <NUM> to be effected in response to detecting the relief condition, for example, the receiving of heat by the temperature responsive portion 210A. However, by effecting the fixing, or substantial fixing, of the spatial disposition of the fixedly couplable portion 210D, relative to the body <NUM>, displacement of the moveable portion 210C, effected in response to the receiving of heat energy by at least a portion of the temperature responsive portion 210A, is more pronounced (such as, for example, a greater displacement of the moveable portion 210C is realized) than the case where a portion of the trigger mechanism <NUM> is not spatially fixed, or substantially fixed, relative to the body <NUM>.

In some embodiments, for example, the trigger mechanism <NUM> is disposed within a sleeve <NUM> that is disposed within the connector <NUM>. The sleeve <NUM> functions to reduce friction between the trigger mechanism <NUM> and the connector <NUM>, during movement of the trigger mechanism <NUM> through the connector <NUM>, in parallel with the displacement of the retainer 210B. In some embodiments, for example, the sleeve <NUM> is disposed in interference fit relationship with the connector <NUM>. In some embodiments, for example, the sleeve <NUM> is made from a plastic, such as polytetrafluoroethylene. In some embodiments, for example, the sleeve <NUM> is made from TEFLON™.

In some embodiments, for example, the temperature responsive portion 210A is disposed at least between the fixedly couplable portion 210D and the moveable portion 210C. In some of these embodiments, for example, the moveable portion 210C includes at least a portion of the temperature responsive portion 210A.

In some embodiments, for example, where the pressure relief apparatus is a thermally actuated pressure relief apparatus, in response to the receiving of heat energy, the heated portion of the temperature responsive portion 210A effects exertion of a tensile force, thereby effecting the displacement of the moveable portion 210C relative to the fixedly couplable portion 210D such that the moveable portion 210C is displaced from the non-actuated position to the actuated position.

In some embodiments (not shown), for example, the moveable portion 210C includes the retainer 210B, such that the retainer 210B translates with the moveable portion 210C, and such that the displacement of the moveable portion 210C, relative to the fixedly coupled portion 210D, effects the displacement of the retainer 210B to release the closure member <NUM> from retention.

In some embodiments, for example, the moveable portion 210C is separate from the retainer 210B, as depicted in <FIG> and <FIG>. In this respect, in some embodiments, for example, the trigger mechanism <NUM> includes a retainer actuator 210X that is separate from the retainer 210B. The retainer actuator 210X is displaceable from a retaining position to a released position. While disposed in the retaining position, the retainer actuator 210X is retaining the retainer 210B in a position relative to the closure member <NUM> such that the retainer 210B prevents the displacement of the closure member <NUM> from the closed position to the open position. While disposed in the released position, the retainer 210B is released from retention by the retainer actuator 210X such that the retainer 210B is displaceable relative to the closure member <NUM> such that retention of the closure member <NUM> by the retainer 210B is releasable, and that the closure member <NUM> is displaceable from the closed position, as depicted in <FIG>, to the open position, as depicted in <FIG>.

In those embodiments where the retainer actuator 210X is separate from the retainer 210B, in some of these embodiments, for example, and referring to <FIG> and <FIG>, the retainer 210B includes a free ball 210BB. In some embodiments, for example, the material of construction of the ball 210BB is steel.

In some embodiments, for example, the retention of the closure member <NUM> in the closed position by the ball 210BB is effected by interference to displacement of the closure member, from the closed position to the open position, by the ball 210BB. In some embodiments, for example, the interference is effected by disposition of the ball 210BB within a recess 208C (such as, for example, a cut-out) of the closure member <NUM>. Co-operatively, in effecting this interference, the retainer actuator 210X and a ball-retaining surface 201A of the body <NUM> prevents, or substantially prevents, release of the ball 210BB from its disposition within the recess, while the retainer actuator 210X is disposed in the retaining position.

In this respect, the ball-retaining surface 201A, prevents, or substantially prevents, displacement of the ball 210BB, relative to the body <NUM>, that is being urged by a pressure differential established between the inlet <NUM> and the outlet <NUM>, that is urging the displacement of the closure member <NUM> from the closed position to the open position. The force (arising from a pressure differential, such as a pressure differential that exceeds the predetermined minimum pressure differential) that is urging the displacement of the closure member <NUM> from the closed position to the open position, in combination with the above-described opposition provided by the ball-retaining surface 201A, results in a net force that urges release of the ball 210BB from the recess 208C, and, while disposed in the retaining position, the retainer actuator 210X opposes such force and retains the ball 210BB within the recess 208C (in the illustrated embodiment, the retainer actuator 210X prevents, or substantially prevents, movement of the ball 210BB along an axis that is orthogonal to the axis along which the closure member <NUM> is movable to the open position). When the retainer actuator 210X becomes disposed in the released position, such opposition is absent, permitting the pressure differential to liberate the ball 210BB from the recess, and thereby releasing the closure member <NUM> from retention by the ball 210BB and enabling its displacement to the open position, in response to application of a pressure differential between the inlet <NUM> and the outlet <NUM> that exceeds the minimum predetermined pressure differential, as explained above.

While the retainer actuator 210X is disposed in the retaining position, and gaseous material is disposed within the tank <NUM> such that a pressure differential, exceeding the predetermined minimum pressure differential, is urging displacement of the closure member <NUM> to the open position, force is transmitted by the closure member <NUM> to the ball 210BB, and the ball 210BB transmits most of the force being applied to the closure member <NUM> onto the body <NUM>, while transmitting a smaller force onto the actuator <NUM>. By having the retainer 210B separated from the temperature responsive portion 210A, such as is the case with the above-described embodiments with the ball 210BB, less frictional resistance is impartable to the moveable portion 210C when it is being displaced by tensile forces resulting from the receiving of heat by the temperature responsive portion 210A, compared to when the retainer 210B is integral with the moveable portion 210C. This allows for greater flexibility in the choice of materials for the temperature responsive portion 210A, which may, for example, be a wire (for example, comprising a shape memory alloy).

In those embodiments where the material of the temperature responsive portion 210A is a shape memory alloy, in some of these embodiments, for example, the temperature, at which the temperature responsive portion 210A assumes a change in shape, is modified with a shape changing temperature modifier <NUM>. In those embodiments, for example, the shape changing temperature modifier <NUM> includes a biasing member <NUM>. The biasing member <NUM>, the temperature responsive portion 210A, and the fixedly couplable portion 210D are cooperatively configured such that, while the fixedly couplable portion 210D is coupled to the tank <NUM>, the biasing member <NUM> urges (or biases) the temperature responsive portion 210A away from the fixedly couplable portion 210D, and the urging effects a change to the shape changing characteristics of the temperature responsive portion 210A.

In some embodiments, for example, the trigger mechanism <NUM> includes a housing <NUM>, such that the moveable portion 210C includes the housing <NUM>. The temperature responsive portion 210A is pinched between a pin <NUM> and the housing <NUM>, such that the temperature responsive portion 210A is coupled to the housing <NUM>. The housing <NUM> contains the biasing member <NUM>. For example, the biasing member <NUM> is a resilient member, such as a spring. For example, the spring is a coil spring made from steel. The biasing member <NUM> is coupled to the body <NUM> with a retainer <NUM>. The retainer <NUM> is fastened to the body <NUM>. For example, the retainer <NUM> is in the form of a nut which threads into complementary threads provided on an external surface of the body <NUM>, thereby retaining the biasing member <NUM> relative to the body <NUM>. For example, the material of the retainer <NUM> is metallic. Suitable metallic materials include brass, aluminum, or stainless steel. For example, the material of the pin <NUM> is a metal, such as steel. In some embodiments, for example, the attachment of the connector <NUM> to the body <NUM> is effected by connection of the connector to the retainer <NUM>.

As depicted in <FIG>, the biasing member <NUM>, the housing <NUM>, and the fixedly couplable portion 210D are cooperatively configured such that, while the fixedly couplable portion 210D is fixedly coupled to the tank <NUM>, the biasing member <NUM> presses against the housing <NUM>, urging the housing <NUM> away from the fixedly couplable portion 210D. The retainer <NUM> includes a passage <NUM> which receives the temperature responsive portion 210A so as to facilitate the coupling of the temperature responsive portion 210A to the shape changing temperature modifier <NUM> and to facilitate movement of the moveable portion 210C (which, in this case, includes the temperature responsive portion 210A). In this respect, while the fixedly couplable portion 210D is fixedly coupled to the tank <NUM>, by pressing against the housing <NUM>, and urging the housing <NUM> away from the fixedly couplable portion 210D, the biasing member <NUM> effects application of a tensile force to the temperature responsive portion 210A such that the shape changing temperature characteristics of the temperature responsive portion 210A are modified.

The biasing member <NUM> and the temperature responsive portion 210A are cooperatively configured, in effect, to calibrate the characteristic temperature of the temperature responsive portion 210A such that the calibrated characteristic temperature corresponds to the desired predetermined temperature threshold at which the trigger mechanism of the pressure relief apparatus <NUM> is desired to release the closure member <NUM>. In some embodiments, for example, the biasing member <NUM> is used when no material has a characteristic temperature that corresponds with the desired predetermined temperature threshold at which the trigger mechanism of the pressure relief apparatus <NUM> is desired to release the closure member <NUM>, or such a material does exist, but it is not feasible to obtain this material.

In some embodiments, for example, the biasing member <NUM> is positioned relative to the housing <NUM> to urge the housing <NUM> away from the fixedly couplable portion 210D, as depicted in <FIG> and <FIG>. As depicted in <FIG> and <FIG>, the biasing member <NUM> and the temperature responsive portion 210A are on the same side of the housing <NUM>. By urging the housing <NUM> away from the fixedly couplable portion 210D, the biasing member <NUM> increases the characteristic temperature of the temperature responsive portion 210A, and also increases the predetermined temperature threshold at which the trigger mechanism of the pressure relief apparatus <NUM> is desired to release the closure member <NUM>. In other embodiments, for example, the biasing member <NUM> is positioned relative to the housing to urge the housing <NUM> towards the fixedly couplable portion 210D. In such an embodiment, for example, the biasing member <NUM> and the temperature responsive portion 210A are on opposite sides of the housing <NUM> (not depicted). By urging the housing <NUM> towards the fixedly couplable portion 210D, the biasing member <NUM> decreases the characteristic temperature of the temperature responsive portion 210A, and also decreases the predetermined temperature threshold at which the trigger mechanism of the pressure relief apparatus <NUM> is desired to release the closure member <NUM>.

As described above, when the pressure relief apparatus <NUM> is a thermally actuated pressure relief apparatus, the trigger mechanism <NUM> comprises the temperature responsive portion 210A coupled to the housing <NUM> of the moveable portion 210C. When heat energy is received by the temperature responsive portion 210A such that the temperature of the temperature responsive portion 210A is at or above a predetermined temperature threshold, the temperature responsive portion <NUM> reduces in length and displaces the moveable portion 210C, relative to the fixedly couplable portion 210D, such that, in response, the retention of the ball 210BB is released by the release actuator 210X (in this respect, the release actuator 210X has now become disposed in the released position), such that the ball 210BB is displaceable relative to the closure member <NUM> with effect that retention of the closure member <NUM> by the retainer 210B is releasable.

While the ball 210BB is released from retention by the retainer actuator 210X, the ball 210BB is displaceable, so as to effect the release of the closure member <NUM> in response to a sufficient pressure differential being provided between the inlet port <NUM> and the outlet port <NUM>, from a closed position to an open position.

In this manner, the pressure relief apparatus <NUM> is a temperature-activated pressure relief apparatus, such that the pressure relief apparatus <NUM> is triggered upon detection of a temperature at or above a predetermined temperature threshold for the trigger mechanism to release the closure member <NUM>.

Other configurations are possible to activate the trigger mechanism <NUM> to release the closure member <NUM>. According to the invention, the trigger mechanism <NUM> is triggered with pressure to release the closure member <NUM>. <FIG> depict a pressure relief apparatus <NUM> that is triggered by either temperature or pressure to release the closure member <NUM>. That is, the pressure relief apparatus <NUM> is thermally actuated or pressure actuated. The closure member <NUM> of the pressure relief apparatus <NUM> as depicted in <FIG> is in the closed position, such that fluid communication between the inlet port <NUM> and the outlet port <NUM> is sealed or substantially sealed.

The pressure relief apparatus <NUM> is generally similar to the pressure relief apparatus <NUM> as depicted in <FIG> and <FIG>, except that the pressure relief apparatus <NUM> can be pressure actuated. In some embodiments, for example, the pressure relief apparatus <NUM> comprises a compartment <NUM> that is disposed for pressurization, for example, by receiving a pressurized fluid such as a pressurized gaseous material, which applies a force on the surfaces defining the compartment <NUM>. In some embodiments, for example, the compartment <NUM> comprises a chamber opening <NUM>. The pressurized fluid in the compartment <NUM> applies a force through this opening <NUM>. The magnitude of this force is a function of the pressure in the compartment <NUM> and the area of the opening <NUM>.

In some embodiments, for example, the compartment <NUM> is defined in the body <NUM> of the pressure relief apparatus <NUM>, such that it is an internal component of the body <NUM> of the pressure relief apparatus <NUM>, as depicted in <FIG>. In other embodiments, for example, the compartment <NUM> is an external component to the body <NUM>. For example, the compartment <NUM> is connected to the body <NUM> by welding or using fastening devices such as a combination of threaded studs, washers and nuts, or by another appropriate fastening device. Where the compartment <NUM> is external to the body <NUM>, the compartment <NUM> is constructed with the same material as the body <NUM>, such as metal. Suitable metallic materials include brass, aluminum, or stainless steel, or a combination of these materials.

In some embodiments, for example, the dimensions, size, and shape of the compartment <NUM> are selected to receive sufficient pressurized fluid for achieving and maintaining a characteristic pressure upon receiving the pressurized fluid. In some embodiments, for example, this characteristic pressure falls within a range of pressures, depending on the pressure of the pressurized fluid. The dimensions and sizing of the compartment <NUM> are selected based on corresponding the characteristic pressure of the compartment <NUM> with the desired predetermined pressure threshold at which the trigger mechanism <NUM> of the pressure relief apparatus <NUM> is configured to release the closure member <NUM>.

In some embodiments, for example, the compartment <NUM> has a spherical, cylindrical, or rectangular shape. In other embodiments, for example, the compartment <NUM> has an irregular geometrical shape.

The dimensions and size of the compartment <NUM> are selected based on the desired predetermined pressure threshold at which the trigger mechanism <NUM> of the pressure relief apparatus <NUM> is configured to release the closure member <NUM>.

The orientation and position of the compartment <NUM> relative to the body <NUM> is determined based on the desired direction of the force applied by the pressurized fluid in the compartment <NUM> through the chamber opening <NUM>. In some embodiments, for example, the compartment <NUM> is positioned relative to the trigger mechanism <NUM> such that the compartment <NUM> fluidly communicates with the trigger mechanism <NUM>. When the compartment <NUM> is pressurized, the pressurized fluid received within the compartment <NUM> is in fluid communication with the trigger mechanism <NUM>, and applies a force through the opening <NUM> on the trigger mechanism <NUM> to urge the trigger mechanism <NUM> from a non-actuating position to an actuating position. As depicted in <FIG>, the pressurized fluid within the compartment <NUM> applies a force through the opening <NUM> on the trigger mechanism <NUM> to urge the moveable portion 210C towards the fixedly couple portion 210D. As depicted in <FIG>, the chamber opening <NUM> of the compartment <NUM> is positioned adjacent to the housing <NUM> of the trigger mechanism <NUM>, such that the compartment <NUM> opposes the temperature responsive portion 210A and the biasing member <NUM>. When the compartment <NUM> is pressurized, the pressurized fluid within the compartment <NUM> applies a force through the opening <NUM> on the housing <NUM>. As depicted in <FIG>, the chamber opening <NUM> is oriented relative to the housing <NUM> such that the force applied to the housing <NUM> is generally perpendicular to the base of the housing <NUM> for urging the moveable portion 210C towards the fixedly couple portion 210D. The force applied on the housing <NUM> by the pressurized fluid in the compartment <NUM> is in a direction that urges the moveable portion 210C towards the fixedly couplable portion 210D.

As depicted in in <FIG> and <FIG>, the pin <NUM> extends into the compartment <NUM>. In some embodiments, for example, the pin <NUM> does not extend into the compartment <NUM>.

In some embodiments, for example, the pressure relief apparatus <NUM> comprises a vent gas conduit <NUM> for directing a pressurized fluid from a pressurized fluid source into the compartment <NUM> to pressurize the compartment <NUM>. A first end of the vent gas conduit <NUM> is fluidly connected to the pressurized fluid source, and the second end of the vent gas conduit <NUM> is fluidly connected to the compartment <NUM>. In some embodiments, for example, the pressurized fluid source is an external pressurized fluid source to the pressure relief apparatus <NUM>.

In some embodiments, for example, the vent gas conduit <NUM> is defined in the body <NUM> of the pressure relief apparatus <NUM>, such that it is an internal component of the body <NUM> of the pressure relief apparatus <NUM>, as depicted in <FIG>. The vent gas conduit <NUM> is configured to effect fluid communication between the outlet port <NUM> and the compartment <NUM>. The compartment <NUM> is disposed for being pressurized by a pressurized fluid from an external pressurized fluid source, the pressurized fluid flowing through the outlet port <NUM> and directed into the compartment <NUM> by the vent gas conduit <NUM>. As shown in <FIG>, the vent gas conduit <NUM> fluidly connects the compartment <NUM> and the outlet port <NUM>, such that a pressurized fluid entering the pressure relief apparatus <NUM> through the outlet port <NUM> is directed into the compartment <NUM> by the vent gas conduit <NUM> and pressurizes the compartment <NUM>. The compartment <NUM> receives the pressurized fluid from the outlet port <NUM> and communicates the received pressurized fluid to the trigger mechanism <NUM>. The pressurized fluid is directed by the vent gas conduit <NUM> past the closure member <NUM>, the retainer 210B, and the ball 210BB into the compartment <NUM>.

In other embodiments, for example, the vent gas conduit <NUM> is an external component to the body <NUM>. For example, the vent gas conduit <NUM> is connected to the compartment <NUM> at one end and the pressurized fluid source at another end by welding or using fastening devices such as a combination of clamps, threaded studs, washers and nuts, or by another appropriate fastening device. Where the vent gas conduit <NUM> is external to the body <NUM>, the vent gas conduit <NUM> is constructed with the same material as the body <NUM>, such as metal. Suitable metallic materials include brass, aluminum, or stainless steel. In some embodiments, for example, the vent gas conduit <NUM> is constructed with a material appropriate for directing the pressurized fluid to the compartment <NUM>, such as plastic or rubber.

The trigger mechanism <NUM> is configured to direct the flow of the pressurized fluid in the vent gas conduit <NUM> into the compartment <NUM>. The trigger mechanism <NUM> is sealingly engaged to the body <NUM> such that the pressurized fluid is prevented, or substantially prevented, from being conducted past the trigger mechanism <NUM>. The trigger mechanism <NUM> is further configured to restrict the pressurized fluid from flowing into the portion of the actuator-receiving passage <NUM> on the side of the housing <NUM> that opposes the compartment <NUM>.

The trigger mechanism <NUM> is disposed relative to the compartment <NUM> such that the pressurized fluid received within the compartment <NUM> is prevented, or substantially prevented, from being conducted past the trigger mechanism <NUM>, such that movement of the trigger mechanism <NUM> is effectable by the pressurized fluid for effecting the release of retention of the closure member <NUM>. In some embodiments, for example, the housing <NUM> and the actuator-receiving passage <NUM> are sized such that the gap defined between the housing <NUM> and the actuator-receiving passage <NUM> has an area that is substantially smaller than the area of the vent gas conduit <NUM>. For example, the area of the gap defined between the housing <NUM> and the actuator-receiving passage <NUM> is less than half of the area of the vent gas conduit <NUM>. As another example, as depicted in <FIG>, a vent gas seal <NUM>, such as an O-ring, is positioned around the housing <NUM> between the compartment <NUM> and the actuator-receiving passage <NUM> to prevent flow of pressurized gas from the compartment <NUM> and the vent gas conduit <NUM> into the portion of the actuator-receiving passage <NUM> on the side of the housing <NUM> that opposes the compartment <NUM>.

In some embodiments, for example, by directing the flow of the pressurized fluid into the compartment <NUM>, and restricting the flow of the pressurized fluid from flowing into the portion of the actuator-receiving passage <NUM> on the side of the housing <NUM> that opposes the compartment <NUM>, the compartment <NUM> is pressurized at or above the predetermined pressure threshold. When the compartment <NUM> is pressurized at or above the predetermined pressure threshold, the force applied to the housing <NUM> by the pressurized fluid in the compartment <NUM> through the chamber opening <NUM> is greater than the force applied to the housing <NUM> that urges the housing <NUM> away from the fixedly couplable portion 210D (e.g. the forces applied to the housing <NUM> by the biasing member <NUM> positioned as depicted in <FIG>, and by fluid that may be in the portion of the actuator-receiving passage <NUM> on the side of the housing <NUM> that opposes the compartment <NUM>), and disposes the trigger mechanism <NUM> from a non-actuating position to an actuating position within the actuator-receiving passage <NUM>, which releases the retainer 210B, with effect that the closure member <NUM> becomes displaceable for effecting fluid communication between the inlet port <NUM> and the outlet port <NUM>.

As depicted in <FIG>, the closure member <NUM>, the retainer 210B, for example the ball 210BB, the compartment <NUM>, the vent gas conduit <NUM> and the trigger mechanism <NUM> are cooperatively configured such that, while: (i) the closure member <NUM> is disposed in the closed position, (ii) the pressure relief apparatus <NUM> is coupled to the tank <NUM> such that the inlet port <NUM> is disposed in fluid communication with contents within the tank <NUM>, (iii) the vent gas conduit <NUM> is fluidly connected to the compartment <NUM> at one end and to a pressurized fluid source on the other end, (iv) the pressurized fluid from the pressurized fluid source is directed into the compartment <NUM> by the vent gas conduit <NUM>, and (v) the compartment <NUM> is pressurized by the pressurized fluid at a pressure below a predetermined pressure threshold, there is an insufficient force applied to the housing <NUM> from the pressurized fluid in the compartment <NUM> to overcome the forces applied to the housing <NUM> that urges the housing <NUM> away from the fixedly coupled portion 210D (e.g. the forces applied to the housing <NUM> by the biasing member <NUM> positioned as depicted in <FIG>, and by fluid that may be in the portion of the actuator-receiving passage <NUM> on the side of the housing <NUM> that opposes the compartment <NUM>) to actuate the trigger mechanism <NUM>. With the trigger mechanism <NUM> in the non-actuating position, the retainer 210B opposes the force being applied to the closure member <NUM> by the pressurized gaseous material within the tank <NUM> that is urging the displacement of the closure member <NUM> from the closed position to the open position, such that the closure member <NUM> is retained in the closed position by the retainer 210B.

As depicted in <FIG>, the closure member <NUM>, the retainer 210B, for example the ball 210BB, the compartment <NUM>, the vent gas conduit <NUM> and the trigger mechanism <NUM> are further cooperatively configured such that, while: (i) the closure member <NUM> is disposed in the closed position, (ii) the pressure relief apparatus <NUM> is coupled to the tank <NUM> such that the inlet port <NUM> is disposed in fluid communication with contents within the tank <NUM>, (iii) the vent gas conduit <NUM> is fluidly connected to the compartment <NUM> at one end and to a pressurized fluid source on the other end, (iv) the pressurized fluid from the pressurized fluid source is directed into the compartment <NUM> by the vent gas conduit <NUM>, and (v) the compartment <NUM> is pressurized by the pressurized fluid at or above a predetermined pressure threshold, there is a sufficient force applied to the housing <NUM> from the pressurized fluid in the compartment <NUM> to overcome the forces applied to the housing <NUM> that urges the housing <NUM> away from the fixedly coupled portion 210D (e.g. the forces applied to the housing <NUM> by the biasing member <NUM> positioned as depicted in <FIG>, and by fluid that may be in the portion of the actuator-receiving passage <NUM> on the side of the housing <NUM> that opposes the compartment <NUM>) to actuate the trigger mechanism <NUM>. With the trigger mechanism <NUM> in the actuating position, the retainer 210B is displaceable, in response to the compartment <NUM> becoming pressurized at a pressure at or above a predetermined pressure threshold, such that the closure member <NUM> becomes released from retention by the retainer 210B and becomes displaceable from the closed position to the open position in response to urging by the contents within the tank <NUM>.

In this respect, in some embodiments, for example, while the trigger mechanism <NUM> is, upon pressurization of the compartment <NUM> at or above a predetermined pressure threshold, disposed in the actuated position such that the closure member <NUM> is released from retention by the retainer 210B as depicted in <FIG>, the closure member <NUM> is displaceable from the closed position to the open position in response to a sufficient pressure differential being provided between the inlet port <NUM> and the outlet port <NUM> (i.e. while the trigger mechanism <NUM> is disposed in the actuated position, the closure member <NUM> is displaced from the closed position to the open position when the pressure differential between the inlet port <NUM> and the outlet port <NUM> exceeds a predetermined minimum pressure differential). In some of these embodiments, for example, the inlet port <NUM> is disposed in fluid communication with the tank <NUM>, and is, thereby, exposed to fluid pressure within the tank <NUM>, and the outlet port <NUM> is disposed in fluid communication with the atmosphere and is, thereby, exposed to atmospheric pressure, such that, so long as the fluid pressure within the tank <NUM> exceeds atmospheric pressure by a predetermined minimum threshold, and so long as the trigger mechanism <NUM> is disposed in the actuated position, the closure member <NUM> will become displaced from the closed position to the open position. When the closure member <NUM> is displaced from the closed position to the open position, the contents of the tank <NUM> are vented out through the outlet port <NUM>.

In this respect, the pressure relief apparatus <NUM> is configured to be vented either upon detection by the temperature responsive portion <NUM> of the temperature at or above the predetermined temperature threshold, or upon pressurization of the compartment <NUM> at or above a predetermined pressure threshold. The trigger mechanism <NUM> and the closure member <NUM> of the pressure relief apparatus <NUM> are cooperatively configured such that the closure member <NUM> becomes released from retention and moveable for effecting establishment of fluid communication between the inlet port <NUM> and the outlet port <NUM> in response to receiving of heat energy by the temperature responsive portion. Further, the trigger mechanism <NUM>, the closure member <NUM>, and the compartment <NUM> of pressure relief apparatus <NUM> are cooperatively configured such that the closure member <NUM> becomes released from retention and moveable for effecting establishment of fluid communication between the inlet port <NUM> and the outlet port <NUM> in response to the communication of the pressurized fluid to the trigger mechanism <NUM> via the compartment <NUM>.

When the contents of the tank <NUM> are vented out through the outlet port <NUM>, in some embodiments, for example, the contents are vented to the atmosphere. In other embodiments, for example, where the contents of the tank pose a safety hazard, a health hazard, an environmental hazard, or the like, the contents of the tank <NUM> are directed to an appropriate venting area or processing equipment using piping, hoses, and other pressurized fluid transporting devices that are appropriate for the particular contents of the tank <NUM>.

As described above, when the pressure relief apparatus <NUM> is triggered by pressure to release the closure member <NUM>, the pressure relief apparatus <NUM> comprises a compartment <NUM> and a vent gas conduit <NUM> for activating the trigger mechanism <NUM> to release the closure member <NUM>. The vent gas conduit <NUM> directs a pressurized fluid from a pressurized fluid source into the compartment <NUM>. When the compartment <NUM> is pressurized at or above the predetermined pressure threshold, the force applied to the housing <NUM> by the pressurized fluid in the compartment <NUM> through the chamber opening <NUM> is greater than the force applied to the housing <NUM> that urges the housing <NUM> away from the fixedly couplable portion 210D (e.g. the forces applied to the housing <NUM> by the biasing member <NUM> positioned as depicted in <FIG>, and by fluid in the portion of the actuator-receiving passage <NUM> on the side of the housing <NUM> that opposes the compartment <NUM>), and disposes the trigger mechanism <NUM> from a non-actuating position to an actuating position within the actuator-receiving passage <NUM>, which releases the retainer 210B, with effect that the closure member <NUM> becomes displaceable for effecting fluid communication between the inlet port <NUM> and the outlet port <NUM>, and vents the contents of the tank <NUM> through the outlet port <NUM>.

In some embodiments, for example, a plurality of relief apparatuses are fluidly connected to each other to create a vent system <NUM> for controlling the pressure of a pressurized system.

The pressurized system that the vent system <NUM> can vent is either a single-tank system or a multi-tank system. In some embodiments, for example, the relief apparatuses of the vent system <NUM> are attached to one tank <NUM> at different positions of the tank <NUM>. In other embodiments, for example, the relief apparatuses of the vent system <NUM> are attached to a multi-tank system, with at least one relief apparatus in fluid communication with each tank <NUM> of the multi-tank system.

In some embodiments, for example, the vent system <NUM> controls pressure of a pressurized system, the pressurized system comprising a first tank and a second tank. The vent system <NUM> comprises the first tank in fluid communication with a first relief apparatus, the first relief apparatus comprising an inlet port and an outlet port, the second tank in fluid communication with a second relief apparatus, the second relief apparatus comprising an inlet port and an outlet port, the outlet port of the first relief apparatus in fluid communication with the outlet port of the second relief apparatus, wherein the second relief apparatus is configured to be triggered for venting the second tank in response to receiving gaseous material vented from the first tank. A vent tube <NUM> effects fluid communication between the outlet port of the first relief apparatus and the outlet port of the second relief apparatus.

In some embodiments, for example, the second relief apparatus is a pressure relief apparatus <NUM> as described herein. In some embodiments, for example, both of the first relief apparatus and the second relief apparatus are pressure relief apparatuses <NUM> as described herein.

In some embodiments, for example, a plurality of pressure relief apparatuses <NUM> are fluidly connected to each other to create the vent system <NUM> for venting the pressurized system, such that when one pressure relief apparatus <NUM> is triggered to vent the contents of the pressurized system, either upon detection of a temperature at or above a predetermined temperature threshold or pressurization of the compartment <NUM> at or above a predetermined pressure threshold, the compartment <NUM> of at least one other pressure relief apparatus <NUM> is pressurized at or above a predetermined pressure threshold, thereby triggering the at least one other pressure relief apparatus <NUM> to vent the pressurized system. In some embodiments, for example, the outlet port <NUM> of each pressure relief apparatus <NUM> in the vent system <NUM> is fluidly connected to the compartment <NUM> of each other pressure relief apparatus <NUM> in the vent system <NUM> through the vent gas conduits <NUM>. In some embodiments, for example, where the vent gas conduit <NUM> is defined in the housing <NUM> as an internal component of the pressure relief apparatus <NUM>, and where the vent gas conduit <NUM> fluidly communicates the compartment <NUM> and the outlet port <NUM>, the outlet ports <NUM> of the pressure relief apparatuses <NUM> in the vent system <NUM> are fluidly connected.

In some embodiments, for example, for the pressure relief apparatuses <NUM> configured into the vent system <NUM>, the pressurized fluid source for pressurizing the compartment <NUM> is the venting of at least one other pressure relief apparatus <NUM> in the vent system <NUM>.

<FIG> depicts an embodiment of the vent system <NUM>, where the outlets <NUM> of two pressure relief apparatuses 300A and 300B are fluidly connected. The pressure relief apparatuses 300A and 300B are generally similar to the pressure relief apparatus <NUM> as described with respect to <FIG> and <FIG>. The inlet ports <NUM> of the pressure relief apparatuses 300A and 300B are configured to be in communication, for example, fluidly coupled, to a pressurized system for receiving the contents of the pressurized system. In some embodiments, for example, the inlet port <NUM> of the pressure relief apparatus 300A is fluidly connected to a tank 100A (not depicted), and the inlet port <NUM> of the pressure relief apparatuses 300B is fluidly connected to a tank 100B (not depicted). While <FIG> depicts the vent system <NUM> comprising two pressure relief apparatuses 300A and 300B that are fluidly connected, in some embodiments, for example, the vent system <NUM> comprises more than two pressure relief apparatuses that are fluidly connected.

In some embodiments, for example, where the outlet ports <NUM> of the pressure relief apparatuses <NUM> are fluidly connected to each other, the outlet ports <NUM> are fluidly connected to each other using the vent tube <NUM>. As depicted in <FIG>, the outlets <NUM> of each of the two pressure relief apparatuses 300A and 300B are connected to the vent tube <NUM> with welding or by using fastening devices such as a combination of threaded studs, washers and nuts, or by another appropriate fastening device. The vent tube <NUM> may comprise a plurality of portions, each portion fluidly coupled to the outlet port of each relief apparatus of the vent system <NUM>. As depicted in <FIG>, the vent tube <NUM> comprises two or more portions, vent tube portion 312A and vent tube portion 312B, such that the vent tube portion 312A is fluidly coupled to the outlet port <NUM> of pressure relief apparatus 300A, and the vent tube portion 312B is fluidly coupled to the outlet port <NUM> of pressure relief apparatus 300B. The contents vented through the outlet port <NUM> of the pressure relief apparatus 300A flow through the vent tube portion 312A, and the contents vented through the outlet port <NUM> of the pressure relief apparatus 300B flow through the vent tube portion 312B. The vent tube <NUM> is constructed using a material that is appropriate for transporting the contents vented from the pressure relief apparatuses <NUM>, such as metal or rubber.

The vent tube portions 312A and 312B are fluidly connected to each other using fastening devices such as welding or a combination of threaded studs, washers and nuts, or by another appropriate fastening device. The vent tube portions 312A and 312B of the vent system <NUM> are further fluidly connected to a common vent <NUM>, such that the contents vented by any pressured relief apparatuses <NUM> within the vent system <NUM> will be directed by the vent tube portions 312A and 312B to vent through the common vent <NUM>. That is, whether the pressure relief apparatus 300A or the pressure relief apparatus 300B depicted in <FIG> is triggered to vent, for example, upon detection of a relief condition such as a temperature at or above a predetermined temperature threshold by the temperature responsive portion 210A, or upon pressurization of the compartment <NUM> at or above a predetermined pressure threshold, the vented contents flow through the vent tube portions 312A and 312B, and then flow through the common vent <NUM> to an area for venting the contents of the pressurized system.

When one or more pressure relief apparatuses <NUM> of the vent system <NUM> is triggered to vent contents, for example, upon detection of a temperature at or above a predetermined temperature threshold or upon pressurization of the compartment <NUM> at or above a predetermined pressure threshold, the pressure of the vent system <NUM> increases, due to the introduction of the vented contents from the pressurized system into the vent system <NUM>. As depicted in <FIG>, since the vent tube portions 312A and 312B of the vent system <NUM> are fluidly connected, the pressure relief apparatuses <NUM> of the vent system <NUM> are also fluidly connected, by virtue of each pressure relief apparatus <NUM> being fluidly connected to its corresponding vent tube portions 312A and 312B. As such, when one or more pressure relief apparatuses <NUM> of the vent system <NUM> is triggered to vent contents, the other pressure relief apparatuses <NUM> of the vent system <NUM> receives pressurized fluid through its respective outlet port <NUM>. For example, the pressurized fluid is pressurized air from the vent system <NUM>, or the contents vented from the pressurized system. The pressurized fluid, which was introduced into the vent system <NUM> from the triggering of one or more pressure relief apparatuses <NUM>, flows from the one or more triggered pressure relief apparatuses <NUM> to the other pressure relief apparatuses <NUM> in the vent system <NUM>. The pressurized fluid pressurizes the compartment <NUM> of at least one other pressure relief apparatus <NUM> and triggers the at least one other pressure relief apparatus <NUM> in the vent system <NUM> to release their respective closure member <NUM> to effect fluid communication between the inlet port <NUM> and the outlet port <NUM> of the at least one other pressure relief apparatus <NUM>.

As depicted in <FIG>, the pressure relief apparatuses 300A and 300B are cooperatively configured such that, when one of the pressure relief apparatuses <NUM> (e.g. pressure relief apparatus 300A) is triggered to release the closure member <NUM>, for example, upon detection of a temperature at or above a predetermined temperature threshold or upon pressurization of the compartment <NUM> at or above a predetermined pressure threshold, to vent a tank <NUM> (e.g. tank 100A), the other pressure relief apparatus <NUM> (e.g. pressure relief apparatus 300B) receives pressurized fluid through its outlet port <NUM> and is triggered to release the closure member <NUM> upon pressurization of its compartment <NUM> at or above a predetermined pressure threshold, where the compartment <NUM> of the other pressure relief apparatus <NUM> is pressurized due to the venting of the first pressure relief apparatus <NUM>.

As depicted in <FIG>, while the pressure relief apparatus 300A is triggered, for example, upon detection of a temperature at or above a predetermined temperature threshold or upon pressurization of the compartment <NUM> at or above a predetermined pressure threshold, to release its closure member <NUM> and vents the tank 100A, thereby increasing the pressure of the vent system <NUM>, for the pressure relief apparatus 300B: (i) the closure member <NUM> is disposed in the closed position, (ii) the pressure relief apparatus 300B is coupled to the tank 100B such that the inlet port <NUM> is disposed in fluid communication with contents within the tank 100B, (iii) the vent gas conduit <NUM> is fluidly connected to the compartment <NUM> at one end and to vent tube portion 312B on the other end, (iv) the pressurized fluid due to venting of the pressure relief apparatus 300A is directed into the compartment <NUM> by the vent gas conduit <NUM>, and (v) the compartment <NUM> of the pressure relief apparatus 300B is pressurized by the pressurized fluid at a pressure at or above a predetermined pressure threshold, there is a sufficient force applied to the housing <NUM> of the pressure relief apparatus 300B from the compartment <NUM> to overcome the forces applied to the housing <NUM> that urges the housing <NUM> away from the fixedly coupled portion 210D (e.g. the forces applied to the housing <NUM> by the biasing member <NUM> positioned as depicted in <FIG>, and by fluid in the portion of the actuator-receiving passage <NUM> on the side of the housing <NUM> that opposes the compartment <NUM>) to actuate the trigger mechanism <NUM> of the pressure relief apparatus 300B. With the trigger mechanism <NUM> in the actuating position, the retainer 210B is displaceable, in response to the compartment <NUM> becoming pressurized at a pressure at or above a predetermined pressure threshold, such that the closure member <NUM> becomes released from retention by the retainer 210B and becomes displaceable from the closed position to the open position in response to urging by the contents within the tank 100B.

In this respect, in some embodiments, for example, while the trigger mechanism <NUM> of pressure relief apparatus 300B is, upon pressurization of the compartment <NUM> at or above a predetermined pressure threshold by the pressurized fluid due to venting of the pressure relief apparatus 300A, disposed in the actuated position such that the closure member <NUM> is released from retention by the retainer 210B as depicted in <FIG>, the closure member <NUM> is displaceable from the closed position to the open position in response to a sufficient pressure differential being provided between the inlet port <NUM> and the outlet port <NUM> (i.e. while the trigger mechanism <NUM> is disposed in the actuated position, the closure member <NUM> is displaced from the closed position to the open position when the pressure differential between the inlet port <NUM> and the outlet port <NUM> exceeds a predetermined minimum pressure differential). In some of these embodiments, for example, the inlet port <NUM> of the pressure relief apparatus 300B is disposed in fluid communication with the tank 100B, and is, thereby, exposed to fluid pressure within the tank 100B, and the outlet port <NUM> is disposed in fluid communication with the vent tube portion 312B and the common vent <NUM> and is, thereby, exposed to the pressure of the vent system <NUM>, such that, so long as the fluid pressure within the tank 100B exceeds the pressure of the vent system <NUM>, such as the pressure of the pressurized fluid received into pressure relief apparatus 300B through its outlet port <NUM>, by a predetermined minimum threshold, and so long as the trigger mechanism <NUM> is disposed in the actuated position, the closure member <NUM> will become displaced from the closed position to the open position. When the closure member <NUM> is displaced from the closed position to the open position, the contents of the tank 100B are vented out through the outlet port <NUM> into the vent tube portion 312B.

In some embodiments, for example, the venting of pressure relief apparatus 300A in the vent system <NUM> triggers at least one other pressure relief apparatus <NUM> in the vent system <NUM> to release their respective closure member <NUM>. All triggered pressure relief apparatuses <NUM> in the vent system <NUM> will vent through their outlets <NUM> through the vent tube portions 312A and 312B and through the common vent <NUM>. As depicted in <FIG>, the venting of pressure relief apparatus 300A triggers the pressure relief apparatus 300B to release its closure member <NUM> and vent the contents of tank 100B, and the vented contents of tanks 100A and 100B flow through the vent tubes portions 312A and 312B, respectively, to the common vent <NUM>.

<FIG> depicts a process S400 for controlling pressure in a tank <NUM> with the pressure relief apparatus <NUM> depicted in <FIG>, where, in response to pressurization of the compartment <NUM> by a flow of pressurized fluid at or above a predetermined pressure threshold, the pressure relief apparatus <NUM> is triggered to release the closure member <NUM> and vent the contents of the tank <NUM>. In some embodiments, for example, the compartment <NUM> receives the pressurized fluid from an external pressurized fluid source, such as a pressurized fluid vented from another tank.

At block S402, the pressure relief apparatus <NUM> is fluidly connected to the tank <NUM>, such that the inlet port <NUM> of the pressure relief apparatus is in fluid communication with the contents of the tank <NUM>, and that an outlet port of the tank <NUM> is fluidly communicating to the inlet port <NUM>. The closure member <NUM> of the pressure relief apparatus <NUM> is disposed in the closed position, so the contents of the tank <NUM> are not vented out through the outlet port <NUM> of the pressure relief apparatus. Further, the trigger mechanism <NUM> and the retainer 210B, are cooperatively configured to retain the closure member <NUM> in the closed position and to prevent the closure member <NUM> from being disposed in the open position due to the force from the contents of the tank <NUM>.

At block S404, the compartment <NUM> of the pressure relief apparatus <NUM> is pressurized with a pressurized fluid from a pressurized fluid source. The pressurized fluid is directed past the closure member <NUM>, the retainer 210B, and the ball 210BB into the compartment <NUM> by the vent gas conduit <NUM>. Where the vent gas conduit <NUM> is an internal component of the pressure relief apparatus <NUM>, as depicted in <FIG>, the vent gas conduit fluidly communicates the compartment <NUM> and the outlet port <NUM>, and the pressurized fluid is directed into the compartment <NUM> through the outlet port <NUM> and through the body <NUM> of the pressure relief apparatus <NUM>. Where the vent gas conduit <NUM> is an external component of the pressure relief apparatus <NUM>, the pressurized fluid is directed into the compartment <NUM> without flowing through the outlet port <NUM>, or a portion of the flow path of the pressurized fluid to the compartment <NUM> is outside the body <NUM> of the pressure relief apparatus <NUM>.

In some embodiments, for example, the pressurized fluid is from an external pressurized fluid source, such as pressurized air or vented contents from another pressure relief apparatus, that has been triggered to release its closure member <NUM> and vent the contents of the tank to which this other pressure relief apparatus is attached. For example, the pressurized fluid is pressurized air generated upon venting of another pressure relief apparatus in fluid communication with the pressure relief apparatus <NUM> cooperatively configured into the vent system <NUM> as depicted in <FIG> and described herein. The pressure relief apparatus <NUM> receives the pressurized fluid through its outlet port <NUM>. Where the pressure relief apparatus <NUM> is configured as part of the vent system <NUM>, the vent tube <NUM> directs the pressurized fluid through the outlet port <NUM>, and the vent gas conduit <NUM> directs the pressurized fluid into the compartment <NUM> of the pressure relief apparatus <NUM>.

At block S406, the compartment <NUM> is pressurized by the pressurized fluid at or above the predetermined pressure threshold. When the compartment <NUM> is pressurized by the pressurized fluid at or above a predetermined pressure threshold, there is a sufficient force applied to the housing <NUM> of the moveable portion 210B from the compartment <NUM> to overcome the forces applied to the housing <NUM> that urges the housing <NUM> away from the fixedly coupled portion 210D (e.g. the forces applied to the housing <NUM> by the biasing member <NUM> positioned as depicted in <FIG>, and by fluid in the portion of the actuator-receiving passage <NUM> on the side of the housing <NUM> that opposes the compartment <NUM>) to actuate the trigger mechanism <NUM>.

At block S408, when the force applied to the housing <NUM> from the pressurized fluid in the compartment <NUM> overcomes the forces applied to the housing <NUM> that urges the housing <NUM> away from the fixedly coupled portion 210D, the trigger mechanism <NUM> is disposed from a non-actuating position to an actuating position. That is, the trigger mechanism <NUM> is disposed from a non-actuating position to an actuating position in response to pressurization of the compartment <NUM> to a pressure at or above a predetermined pressure threshold.

At block S410, with the trigger mechanism <NUM> in the actuating position, the retainer 210B is displaceable, in response to the compartment <NUM> becoming pressurized at a pressure at or above a predetermined pressure threshold, such that the closure member <NUM> becomes released from retention by the retainer 210B and becomes displaceable from the closed position to the open position in response to urging by the contents within the tank <NUM>.

At block S412, the closure member <NUM> is displaceable from the closed position to the open position in response to a sufficient pressure differential being provided between the inlet port <NUM> and the outlet port <NUM> (i.e. while the trigger mechanism <NUM> is disposed in the actuated position, the closure member <NUM> is displaced from the closed position to the open position when the pressure differential between the inlet port <NUM> and the outlet port <NUM> exceeds a predetermined minimum pressure differential). In some of these embodiments, for example, the inlet port <NUM> is disposed in fluid communication with the tank <NUM>, and is, thereby, exposed to fluid pressure within the tank <NUM>, and the outlet port <NUM> is disposed in fluid communication with the atmosphere and is, thereby, exposed to atmospheric pressure, such that, so long as the fluid pressure within the tank <NUM> exceeds atmospheric pressure by a predetermined minimum threshold, and so long as the trigger mechanism <NUM> is disposed in the actuated position, the closure member <NUM> will become displaced from the closed position to the open position. When the closure member <NUM> is displaced from the closed position to the open position, fluid communication is established between the inlet port <NUM> and the outlet <NUM>, and the contents of the tank <NUM> are vented out through the outlet port <NUM>.

In some embodiments, for example, when the contents of the tank <NUM> are vented out through the outlet port <NUM>, the contents are vented to the atmosphere. In other embodiments, for example, where the contents of the tank pose a safety hazard, a health hazard, an environmental hazard, or the like, the contents of the tank <NUM> are directed to an appropriate venting area or processing equipment using piping, hoses, and other pressurized fluid transporting devices that are appropriate for the particular contents of the tank <NUM>. Where the pressure relief apparatus <NUM> is configured as part of the vent system <NUM> as depicted in <FIG>, the contents that are by the pressure relief apparatuses <NUM> that were triggered are vented through the vent tubes <NUM> and through the common vent <NUM>.

In some embodiments, for example, the pressure relief apparatus <NUM> comprises the temperature responsive portion 210A that triggers the pressure relief apparatus <NUM> upon detection of a temperature at or above a predetermined temperature threshold to release the closure member <NUM> to vent the tank <NUM> to which the pressure relief apparatus <NUM> is attached. The pressure relief apparatus <NUM> also comprises the compartment <NUM> that triggers the pressure relief apparatus <NUM> upon detection of a pressure at or above a predetermined pressure threshold to release the closure member <NUM>, to vent the tank <NUM> to which the pressure relief apparatus <NUM> is attached. The pressure relief apparatus <NUM> is configured to be vented upon detection of two types of relief conditions, namely temperature and pressure, which provides flexibility and increases the number of scenarios in which the pressure relief apparatus <NUM> is usable. For example, the pressure relief apparatus <NUM> is usable to vent the tank <NUM> if the tank is exposed to high pressure, high temperature, or both. The pressure relief apparatus <NUM> is also usable if the tank <NUM> is exposed to high pressure or high temperature, but not at the same instance.

In some embodiments, for example, as depicted in <FIG>, the vent system <NUM> comprising two or more pressure relief apparatuses <NUM> is used to vent a multi-tank system. One of the pressure relief apparatuses <NUM> is triggered by other pressure relief apparatuses <NUM> in the same vent system <NUM>. When configured into the vent system <NUM>, the vented contents from one pressure relief apparatus <NUM> increases the pressure in the vent system <NUM> and triggers at least one of the other pressure relief apparatuses <NUM> in the vent system <NUM> to release its closure member <NUM> and vent the contents of the tank <NUM> to which it is connected. That is, for a multi-tank system configured with the vent system <NUM>, the venting of one tank in the multi-tank system causes the other tanks in the multi-tank system to vent.

The vent system <NUM> protects the tanks in a pressurized system, such as a multi-tank system, from undesirable external elements, such as a fire. The fire, for example, only affects one tank <NUM> in the multi-tank system, or affects only one tank <NUM> for an extended period of time before affecting the other tanks in the multi-tank system. In these scenarios, the pressure relief apparatus <NUM> configured as part of the vent system <NUM> that is installed on the one tank <NUM> detects the temperature of the fire being at or above the predetermined temperature threshold and release the closure member <NUM> and vent the tank <NUM>. However, in some embodiments, for example, the pressure relief apparatuses <NUM> installed on the other tanks do not detect the fire. Yet, the fire still presents a safety hazard even if exposed to just one of the tanks in the multi-tank system. In some multi-tank systems, the tanks in the multi-tank system are interconnected, such that the contents from the other tanks flow into the tank <NUM> affected by the fire, effectively refilling the tank <NUM> while the pressure relief apparatus <NUM> vents its contents. This increases the amount of time required to vent the affected tank <NUM>. Further, the unaffected tanks may refill the affected tank <NUM> at a rate greater than the rate that the tank <NUM> is being vented. However, since the pressure relief apparatus <NUM> installed on the tank <NUM> is configured with the other pressure relief apparatuses in the multi-tank system as part of the vent system <NUM>, the other pressure relief apparatuses detect the pressure increase in the vent system <NUM> as the pressure relief apparatus <NUM> vents the contents of the tank <NUM>, and the other pressure relief apparatuses vent the other tanks in the multi-tank system. The vent system <NUM> vents the contents in the multi-tank system and mitigates the hazard presented by the fire, even if the fire affects only a portion of the multi-tank system.

In some embodiments, for example, the pressure relief apparatus <NUM> as depicted in <FIG> and the vent system <NUM> as depicted in <FIG> are installed on various configurations of pressurized systems, such as an individual tank or a multi-tank system. In some embodiments, for example, one pressure relief apparatus <NUM> is installed on a relatively small tank, such as a compressed natural gas tank in an automobile such as a truck or bus, or a relatively large tank such as a tank in a tank farm. In some embodiments, for example, the vent system <NUM> is installed in a pressurized system such as a multi-tank system comprising a plurality of compressed natural gas tanks in an automobile such as a truck or bus, or a plurality of tanks in a tank farm. In some embodiments, for example, the vent gas system <NUM> is also installed in a single tank, where the pressure relief apparatuses <NUM> of the vent gas system <NUM> are installed at various positions on the single tank. When a plurality of pressure relief apparatuses <NUM> are installed on a single tank, it increases the range for which the relief condition, such as a temperature at or above a predetermined temperature threshold or a pressure at or above a predetermined pressure threshold, is detected by the pressure relief apparatuses <NUM>.

In some embodiments, for example, the pressure relief apparatus <NUM> and the vent system <NUM> are configured to vent the tanks <NUM> to which they are attached while mitigating leaks, and do not use more pressurized conduits than needed. For example, the vent gas conduit <NUM> is an internal component of the pressure relief apparatus <NUM>, so additional hoses, pipes, and other appropriate conduits are not required for directing the pressurized fluid into the compartment <NUM>. As another example, the pressure relief apparatuses <NUM> of the vent system <NUM> is fluidly connected to each other at their respective outlets <NUM> using the vent tubes <NUM>. One of the pressure relief apparatuses <NUM> of the vent system <NUM> triggers the other pressure relief apparatuses <NUM> in a multi-tank system without having permanent pressurized connections between the tanks <NUM> themselves, which otherwise presents a risk of leaks.

The preceding discussion provides many example embodiments. Although each embodiment represents a single combination of inventive elements, other examples may include all possible combinations of the disclosed elements. Thus if one embodiment comprises elements A, B, and C, and a second embodiment comprises elements B and D, other remaining combinations of A, B, C, or D, may also be used.

Although the embodiments have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein.

Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present invention, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed, that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.

Claim 1:
A method of controlling pressure in a tank (<NUM>), comprising:
receiving a flow of pressurized fluid from an external pressurized fluid source into a compartment (<NUM>) defined in a pressure relief apparatus (<NUM>) of the tank;
in response to the receiving of the flow of pressurized fluid, activating a trigger mechanism (<NUM>) of the pressure relief apparatus, the trigger mechanism comprising a temperature responsive portion (210A), to release a closure member (<NUM>) of the pressure relief apparatus from retention, thereby establishing fluid communication between an inlet port (<NUM>) and an outlet port (<NUM>) of the pressure relief apparatus for opening the pressure relief apparatus.