Fire extinguishing equipment, including distributed control systems
The fire suppression system addresses inefficiencies and costs by enabling partial automatic control of fluid flow and pressure management, enhancing efficiency and safety through retrofitable automation.
Patent Information
- Application Number
- JP2025512072
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-08-25
- Filing Date
- 2023-08-25
- Publication Date
- 2025-08-22
AI Technical Summary
Conventional fire suppression systems require manual operation by an engineer, leading to inefficiencies and potential human error, and retrofitting automated systems to existing trucks is costly.
A fire suppression system with discharge valve control assemblies and pressure sensors that allow for partial automatic control of fluid flow, enabling remote nozzle operation and pressure management, which can be retrofitted to existing trucks.
Enhances fire suppression efficiency and safety by reducing human error and providing cost-effective automation, while ensuring sufficient fluid pressure for hose lines.
Smart Images

Figure 2025527770000001_ABST
Abstract
Description
[Technical Field]
[0001] This application claims priority to U.S. Provisional Patent Application No. 63 / 373,516, filed August 25, 2022, the disclosure of which is incorporated herein by reference in its entirety.
[0002] FIELD OF THE DISCLOSURE The present disclosure relates generally to control systems, and more particularly to control systems for use in controlling fire suppression devices. [Background technology]
[0003] Fire pump trucks (broadly referred to herein as "fire suppression equipment") are used to extinguish fires by pumping fluid (e.g., water, foam, or other fire retardant) from a source through hose lines, where the fluid can be directed (i.e., sprayed) at a fire to easily extinguish or contain the fire. Known pump trucks include a control system used to coordinate the operation of the truck and control the flow of fluid from the truck to the hose lines. Such control systems typically include multiple valves used to control the flow of fluid from a storage tank on the transported truck or from other fluid sources (e.g., fire hydrants) to the fire pump. The valves also facilitate controlling the flow of fluid from the fire pump to the fire hose or other discharge device. Known control systems include pressure and flow sensors used to monitor the pressure and flow rate of fluid at various locations within the pump truck. For example, a pressure sensor may monitor the pressure of fluid received by the fire pump from the source. Generally, the pump truck's controls used to regulate the valves and fire pump are typically located on a control panel on the side of the pump truck.
[0004] During use, conventional pump trucks require an operator, typically referred to as an engineer, to manually operate the pump truck's controls. More specifically, the engineer manually operates the controls to vary the flow rate and / or control the pressure of the liquid output from the pump truck to the hose. Furthermore, during operation, a firefighter positioned near the nozzle of a hose connected to the pump truck verbally communicates (typically via a handheld radio) to the engineer the desired change in flow rate and / or pressure of the liquid delivered through the hose to the nozzle. In response, the engineer manually adjusts the controls to achieve the desired change in flow rate and / or pressure of the liquid delivered through the hose. It is common for one engineer to be responsible for monitoring and responding to communications from multiple firefighters, each with a separate hose connected to the same pump truck.
[0005] Some known fire suppression systems use automated control systems that can automatically control at least some of the operations traditionally handled by an operator. Known systems utilize one or more controllers that can be communicatively linked to fluid control components, such as discharge valves and / or pumps, of a fire suppression apparatus. However, such systems are generally complex to install and may require the replacement of several functional components of existing, pre-manufactured trucks. As a result, retrofitting such systems to existing trucks can be costly. As used herein, the term "engineer" refers to a firefighter typically stationed at a fire suppression apparatus whose role involves controlling the operation of the apparatus. As used herein, the term "nozzleman" generally refers to a firefighter whose role is to control and / or operate the nozzle of a fire suppression apparatus to direct a stream of fluid toward a target area. As used herein in connection with a hoseline or nozzle, the terms "charge" or "charging" refer to supplying pressurized fluid to the hoseline and / or nozzle. Summary of the Invention
[0006] In one aspect, a fire suppression system is provided. The fire suppression system includes a pump, a nozzle for directing a fluid flow from the pump toward a target area, a nozzle component coupled to the nozzle, the nozzle component having a first transceiver and an indicator, a fluid line connecting the pump to the nozzle, and a discharge valve control assembly. The discharge valve control assembly includes a discharge valve for controlling fluid flow between the pump and the nozzle, a pressure sensor coupled to the fluid line between the pump and the discharge valve, and a second transceiver for providing communication between the nozzle component and the discharge valve control assembly. The discharge valve control assembly is configured to receive a request to charge a hose portion of the fluid line and, in response to receiving the request, determine whether to open the discharge valve based on the fluid pressure detected by the pressure sensor.
[0007] In another aspect, a discharge valve control assembly for use in a fire suppression system is provided. The discharge valve control assembly includes a discharge valve controlling fluid flow through a fluid line extending from a pump to a nozzle of the fire suppression system, a pressure sensor coupled to the fluid line upstream of the discharge valve, and a transceiver providing communication with a nozzle component coupled to the nozzle. The discharge valve control assembly is configured to receive a request from the nozzle component to charge a hose portion of the fluid line and, in response to receiving the request, determine whether to open the discharge valve based on the fluid pressure detected by the pressure sensor.
[0008] In yet another aspect, a method of operating a fire suppression system is provided, the method including: transmitting a first signal from a transceiver of a fire suppression system fire truck to a nozzle component indicating that a hose segment of a fluid line is ready to be charged; receiving a second signal from the nozzle component at the transceiver including a request to charge the hose segment; determining to charge the fluid line based on a fluid pressure detected by a pressure sensor and a predetermined minimum pressure stored in memory, the pressure sensor being disposed in the fluid line upstream of a discharge valve; and automatically controlling the discharge valve to open to charge the hose segment in response to the determination. [Brief explanation of the drawings]
[0009] [Figure 1] 1 is a schematic diagram of an exemplary fire suppression system.
[0010] [Figure 2] FIG. 2 is a schematic diagram of a control system for the fire extinguishing system shown in FIG. 1.
[0011] [Figure 3] FIG. 3 is a schematic diagram of a communications network for use with the control system of FIG. 2.
[0012] [Figure 4] FIG. 3 is a schematic diagram of an alternative communication network for use with the control system of FIG. 2.
[0013] [Figure 5] FIG. 1 is a schematic diagram of an alternative fire suppression system.
[0014] [Figure 6] FIG. 6 is a schematic diagram of an alternative control system for the fire suppression system shown in FIG. 5.
[0015] [Figure 7] FIG. 1 is a schematic diagram of another alternative fire suppression system.
[0016] [Figure 8] FIG. 8 is a flow diagram of an exemplary method of operating the fire suppression system shown in FIGS. DETAILED DESCRIPTION OF THE INVENTION
[0017] The exemplary systems and methods described herein overcome the shortcomings of known fire suppression control systems by enabling at least partial automatic control of fire suppression system components. For example, some embodiments described herein include a system that can be retrofitted to a non-automated fire truck and can enable pressure control at the fire suppression system's remote nozzles and / or notify the suppression crew ("attack crew" or "nozzle man") at each nozzle when the truck does not have enough fluid pressure to charge the respective lines. As a result, the systems and methods described herein facilitate increasing the efficiency of fire suppression systems in a cost-effective and reliable manner, while simultaneously improving firefighter safety by reducing the likelihood of human error.
[0018] Figure 1 is a schematic diagram of an exemplary fire suppression system 100. Figure 2 is a schematic diagram of a control system 102 of the fire suppression system 100 shown in Figure 1.
[0019] In the exemplary embodiment, the fire suppression system 100 includes a fire suppression apparatus 104, such as a fire truck. Coupled to the fire suppression apparatus 104 is a pump 106 and a tank 108. A fire suppression or fire-suppressing liquid is stored in the tank 108. The tank 108 is coupled to the pump 106 via a tank supply line 110 to selectively supply fluid to the pump 106. A tank supply valve 112 coupled to the tank supply line 110 provides control of the flow of fluid from the tank 108 to the pump 106. A tank recirculation line 114 allows for recirculation of fluid from the pump 106 to the tank 108. A tank recirculation valve 116 coupled to the tank recirculation line 114 provides control of the flow of fluid from the pump 106 to the tank 108. In the embodiment of FIG. 1, the recirculation line 114 to the tank 108 is also used to fill the tank 108 with fluid from a fluid source 117. In other embodiments, the fire suppression system 104 may include separate recirculation and fill lines extending from the pump 106 to the tank 108, with the tank 108 and fill line each having its own selectively controllable valve thereon. In further embodiments, the fire suppression system 100 may not include the recirculation line 114 and the recirculation valve 116.
[0020] Fluid source 117 is coupled to pump 106 via source line 118. Source valve 120 is coupled to source line 118 to facilitate control of fluid flow from fluid source 117 to pump 106. In some embodiments, a pressure sensor (not shown) is coupled to source line 118 (e.g., at the inlet manifold of fire suppression system 104) to measure the operating pressure of the fluid in source line 118. In the exemplary embodiment, the fluid dispensed from fluid source 117 is water. In other embodiments, the fluid dispensed from source 117 may be other fluids, such as, but not limited to, foam or other fire-retardant fluids. In the exemplary embodiment, fluid source 117 is a continuous fluid source 117 embodied as a fire hydrant. In other embodiments, fluid source 117 may be other sources of fluid, such as a river, lake, or other body of water. In an exemplary embodiment, the pump 106 is operable to selectively fill the tank 108 with fluid from a fluid source 117 using a tank recirculation valve 116 and / or a fill valve (not shown) coupled to the tank 108.
[0021] The first nozzle 122 is connected to the pump 106 by a first fluid line 124, and the second nozzle 126 is connected to the pump 106 by a second fluid line 128. The first and second nozzles 122, 126 may be carried by and / or selectively positioned by a nozzleman. The pump 106 is operable to receive fluid from either the source line 118 or the tank supply line 110 and supply pressurized fluid to the first and second fluid lines 124, 128 and the first and second nozzles 122, 126 for discharge from the nozzles 122, 126 during firefighting operations. While only two fluid lines 124, 128 are illustrated in FIG. 1 , it should be understood that in other embodiments, more or fewer fluid lines and associated valves, nozzles 122, 126, and pressure sensors may be used.
[0022] 1 as single lines, it should be understood that the source line 118, the tank supply line 110, the tank recirculation line 114, and the first and second fluid lines 124, 128 may include separate lines, manifolds, or other intervening structures connected therebetween. For example, the source valve 120 and / or pressure sensor (not shown) on the source line 118 may be located on an intake manifold of the fire suppression system 104 that is fluidly connected between the source 117 and the pump 106. Additionally, the first and second fluid lines 124, 128 may be connected to the pump 106 via an outlet manifold (not shown), which may include the features of the first and second fluid lines 124, 128 as described herein.
[0023] In the exemplary embodiment, a first discharge valve control assembly 130 is coupled to the first fluid line 124, and a second discharge valve control assembly 132 is coupled to the second fluid line 128. The first and second discharge valve control assemblies 130, 132 are substantially identical except where otherwise described herein. Each discharge valve control assembly 130, 132 includes a discharge valve 134, 136 and a pressure sensor 138, 140. The discharge valves 134, 136 are selectively movable between an open state and a closed state to control the flow of fluid from the pump 106 to the corresponding nozzles 122, 126. In particular, each discharge valve control assembly 130, 132 is coupled to a discharge manifold (not shown) of the fire suppression system 104. The pump 106 supplies fluid at a uniform fluid pressure to the discharge manifolds associated with each of the discharge valves 134, 136.
[0024] Each of the fluid lines 124, 128 includes a first portion 142 that extends from the pump 106 to a corresponding one of the discharge valves 134, 136, or alternatively, to a discharge manifold (not shown). The first portions 142 of the fluid lines 124, 128 are generally disposed internal to the fire suppression system 104. The fluid lines 124, 128 also include a second portion 144 (also referred to herein as a “hose line” or “hose portion”). The second portions 144 extend from the respective discharge valves 134, 136 to the corresponding nozzles 122, 126 and are disposed substantially external to the fire suppression system 104. In the exemplary embodiment, the discharge valves 134, 136 are exposed external to the fire suppression system 104, and the hose line 144 is coupled to the corresponding discharge valve 134, 136. In other embodiments, the discharge valves 134, 136 may be disposed at least partially internal to the fire suppression system 104.
[0025] First and second pressure sensors 138, 140 are coupled to the first and second hose lines 124, 128, respectively, upstream of the corresponding discharge valves 134, 136, and allow for measurement of the operating pressure of the fluid flowing from the pump 106 to the discharge valves. In particular, as described herein, the first and second pressure sensors 138, 140 allow the fluid pressure ready to be provided to the hose line 144 to be checked before the hose line 144 is charged. That is, the first and second pressure sensors 138, 140, respectively, measure the operating pressure of the fluid delivered by the pump 106 even when the discharge valves 134, 136 are closed. In other embodiments in which a pre-charge fluid pressure check is not required, such as in embodiments in which the control system 102 is configured to control the pump 106 in response to a charge request from a nozzleman, as described in more detail below, the first and second pressure sensors 138, 140 upstream of the discharge valves 134, 136 may not be included in the fire suppression apparatus 104. In a further embodiment, the first and second upstream pressure sensors 138, 140 may be provided as a single pressure sensor coupled between the pump 106 and the discharge valves 134, 136 or discharge manifold (not shown).
[0026] Third and fourth pressure sensors 145, 146 are downstream from the discharge valves 134, 136 to measure fluid pressure in the respective hose lines 144 after the hose lines 144 are charged. While the pressure sensors 138, 140, 145, 146 are shown in the embodiment of FIG. 1 as separate components from the discharge valves 134, 136, in other embodiments, the pressure sensors 138, 140, 145, 146 may be coupled to and / or integrated with the corresponding discharge valves 134, 136 to measure fluid pressure within the discharge valves 134, 136. In an exemplary embodiment, the pressure sensors 145, 140, 145, 146 are each transducers. In alternative embodiments, the pressure sensors 138, 140, 145, 146 may each measure the flow rate of fluid in the system. In further alternative embodiments, the pressure sensors 138, 140, 145, 146 may be any sensors that enable the system to function as described herein.
[0027] In some embodiments, the discharge valve control assemblies 130, 132, or at least a portion of the discharge valve control assemblies 130, 132, are removably coupled to the fire suppression apparatus 104 to allow the fluid control system 102 to be retrofitted to an existing fire suppression apparatus 104. In further embodiments, an additional pressure sensor (not shown) may be provided in the first hose line 124 and / or the first nozzle 122 to measure the operating pressure of the fluid at the first nozzle 122.
[0028] In the exemplary embodiment, the first nozzle component 148 is coupled to the first nozzle 122, and the second nozzle component 150 is coupled to the second nozzle 126. As described in more detail below with respect to FIG. 2 , each of the nozzle components 148, 150 wirelessly communicates with a respective one of the discharge valve control assemblies 130, 132 to provide information to the nozzleman and relay commands from the nozzleman to the fire suppression system 104 during use. In some embodiments, the nozzle components 148, 150 are paired with the discharge valve control assemblies 130, 132. In other embodiments, communication between the nozzle components 148, 150 and the discharge valve control assemblies 130, 132 may be routed via an additional communication component, such as a radio (not shown in FIG. 1 ). The first and second nozzle components 148, 150 are substantially identical, except that each nozzle component 148, 150 is wirelessly paired with a different corresponding discharge valve control assembly 130, 132 of the fire suppression system 104.
[0029] Referring to FIG. 2, in an exemplary embodiment, first nozzle component 148 includes a nozzle transceiver 152 and, optionally, further includes any of an interface 154, a nozzle display 156, an indicator 158, a nozzle pressure sensor 160, or a locator beacon 162.
[0030] The interface 154 receives input from a nozzleman operating the nozzle 122 (see FIG. 1), such as, but not limited to, a request for a charge and / or a request for a particular fluid pressure at the nozzle 122 and / or a request to gradually increase or decrease the pressure in the hose line 144 (see FIG. 1). Suitable interfaces 154 may include, but are not limited to, push buttons, switches, a touch screen, or a twistable collar.
[0031] The nozzle display 156 may display or audibly communicate one or more operating parameters of the fire suppression apparatus 104, such as tank level, source fluid pressure, and / or pressure at the nozzle. The indicator 158 provides a visual, visual, and / or tactile indicator to the nozzle operator that the corresponding hose line 144 (see FIG. 1) is charged and / or ready to be charged. In other embodiments, the indicator 158 may be provided by the nozzle display 156. The nozzle pressure sensor 160 detects the pressure of the fluid at the nozzle 122 (see FIG. 1). The locator beacon 162 provides a visual and / or visual locator of the nozzle 122 used to identify the nozzle 122 from a distance and potentially in smoke-filled conditions. The nozzle transceiver 152 is communicatively coupled, or “wirelessly linked,” to a corresponding valve transceiver 153 of the first discharge valve control assembly 130. The first nozzle component 148 also includes a nozzle component controller 164 in communication with the processor 166 and a memory 168 that stores instructions.
[0032] 1 shows nozzle components 148, 150 coupled to nozzles 122, 126, it should be understood that nozzle components 148, 150 and / or portions of nozzle components 148, 150 are not necessarily integral with nozzles 122, 126, but may instead be located anywhere along hose line 144 between discharge valves 134, 136 and the fluid outlets of nozzles 122, 126. For example, in some embodiments, nozzle transceiver 152, nozzle pressure sensor 160, indicator 158, interface 154, locator beacon 162, and / or nozzle component controller 164 may be provided as components separate from nozzle 122 that are coupled to hose line 144 upstream from the respective nozzles 122, 126, such as at the inlets (not shown) of nozzles 122, 126.
[0033] In the exemplary embodiment, first discharge valve control assembly 130 further includes a discharge controller 170 including a processor 172 and a memory 174 that stores instructions. First discharge valve control assembly 130 further includes a system input port 176 for providing communication between discharge valve control assembly 130 and equipment components 178 (see FIG. 1 ) of fire suppression system 104. Exemplary equipment components 178 may include a pump control component 180, a tank level sensor 182 for measuring the volume level of tank 108 (see FIG. 1 ), a pump pressure sensor 184, and / or a source line pressure sensor 188. Equipment components 178 may also include a source valve actuator 186 that actuates source valve 120, a recirculation valve actuator 189 that actuates recirculation valve 116, and a supply valve actuator 191 that actuates supply valve 116, as shown in FIG. 1 . In other embodiments, first discharge valve control assembly 130 may be communicatively coupled to equipment pieces 178 of fire suppression apparatus 104 via any suitable wireless and / or wired communication system that enables control system 102 to function herein. For example, in some embodiments, fire suppression apparatus 104 may include a controller area network (“CAN”) that provides communication between first discharge valve control assembly 130 and at least one or more of equipment pieces 178.
[0034] Pump control component 180 may include components (not shown) operable to adjust the operating state of pump 106 and, therefore, the pressure of the fluid provided to hose line 144. In an exemplary embodiment, operation of pump 106 is manually controlled (e.g., by an engineer at a control panel of fire suppression apparatus 104). For example, controls for pump 106 may be provided at an interface with a pressure regulator (not shown) or at a separate control panel of fire suppression apparatus 104. Additionally, if operation of pump 106 is manually controlled, pump control component 180 may include an indicator (not shown) on fire suppression apparatus 104 that signals an engineer to manually adjust operation of pump 106. In other embodiments, control system 102 may be configured to automatically control pump 106 based on input to control system 102, such as a message received from a nozzleman at nozzle components 148, 150. For example, without limitation, in some embodiments, pump control component 180 is a pressure regulator that includes a control device in communication with a prime mover (e.g., as shown in the embodiment of FIG. 5). In such embodiments, the controller may automatically control the operation of the pump 106 based on signals received from the discharge valve control assemblies 130, 132 or other inputs to the control system 102. In further embodiments, the pump 106 may be automatically controlled, with manual control provided as an override to the automatic control.
[0035] In other embodiments, first nozzle component 148 may not include nozzle component controller 164 and / or first discharge valve control assembly 130 may not include discharge controller 170. In still other embodiments, the functions described herein as being performed by either nozzle component controller 164 and / or discharge controller 170 may be performed by a single controller or multiple controllers.
[0036] In an exemplary embodiment, the nozzle components 148, 150 and / or discharge valve control assemblies 130, 132, along with the apparatus component 178, collectively define the control system 102 of the fire suppression apparatus 104 to facilitate at least partially automatic control of fluid flow within the fire suppression system 100. As one example, the fire suppression system 100 may automatically control the operation of the pump 106 and / or the actuation position of the discharge valves 134, 136 based on fluid pressure measured by pressure sensors 138, 140, 145, 146 in the line 144 and / or a request to charge the line received at the nozzle component 148. Such automatic control provides confirmation that the fluid provided by the pump 106 is at sufficient pressure to continue charging the hose line 144 and, therefore, prevents charging of the line 144 if the fluid pressure provided by the pump 106 is below a minimum threshold. For example, upon arriving at a scene, firefighters may deploy each nozzle 122, 126 and call for charging of the respective line when in attack position. 1 , an engineer may operate the pump 106 to provide a particular fluid to each line. Pressure demands may be input at the nozzle component 148, such as by an interface 154 (e.g., a push button, switch, touch screen, etc.) on the nozzle component 148 and / or by other controls (not shown) on the fire suppression apparatus 104. Additionally, the discharge valve control assemblies 130, 132 may prevent charging of each line (e.g., by maintaining the corresponding discharge valve 134, 136 closed) until the associated pressure sensor 138, 140 detects that the pressure in the respective line exceeds a minimum pressure threshold required to charge the line 144.
[0037] In an exemplary embodiment, if the discharge valve control assemblies 130, 132 detect that the pressure measured by the corresponding pressure sensor 138, 140 equals or exceeds a minimum pressure threshold, the discharge valve control assemblies 130, 132 may automatically open the respective discharge valve 134, 136 by controlling the corresponding discharge valve actuator 133 (e.g., in response to a request to charge the corresponding line) and / or may send a signal to the corresponding nozzle component 148 to cause the nozzle component 148 to indicate to a firefighter that the line is ready to be charged and / or that the line is charged (e.g., via the indicator 158). If the detected pressure is below the minimum pressure threshold, the discharge valve control assemblies 130, 132 may prevent charging of the line (e.g., by keeping the discharge valve 134, 136 closed). Additionally, in response to detecting that the fluid pressure is below the minimum threshold, the control system 102 may also provide a signal to the corresponding nozzle component 148 to indicate to a firefighter that the line is not yet ready to be charged. Additionally or alternatively, if insufficient pressure to charge line 144 is detected, discharge valve control assembly 130 may notify an engineer at fire suppression apparatus 104 (e.g., a control panel) that there is insufficient pressure in pump 106 to charge the line. Low fluid pressure indicator 158 may include an audible or visual notification perceptible to the engineer. Alternatively, control system 102 may automatically send a signal to pump control component 180, causing pump control component 180 to automatically adjust the operating state of pump 106 (e.g., by increasing the speed of pump 106) to increase fluid pressure.
[0038] In an exemplary embodiment, a minimum pressure threshold for charging each line 144 is stored in memory 168 of the discharge controller 170. Different thresholds may be provided for each discharge valve control assembly 130 and / or each nozzle component 148. In some embodiments, the pressure threshold for each discharge valve control assembly 130 may be manually set by a user. In other embodiments, a machine learning algorithm may be used to adjust the minimum pressure over subsequent use based on a historical average of detected line 144 pressures accumulated over time. As an example, if friction losses in the system (e.g., in the hose lines 144) repeatedly result in 50 pounds per square inch (“psi”) of fluid pressure at the nozzle 122 while the pump 106 is operating at a pump outlet pressure of 80 psi, the control system 102 will initialize at 80 psi or start with an initial charge of 80 psi, measure the pressure at the nozzle 122 using the nozzle pressure sensor 160, and adjust the pump speed accordingly. Because the hose lines 144 may change over time on the truck, the machine learning algorithm may adjust after several uses to changes in hose loads. In some embodiments, the discharge valve control assemblies 130, 132 may further be communicatively connected to one or more components of the fire suppression system 100 to relay information for display at the corresponding nozzle components 148, 150. For example, in some such embodiments, the discharge valve control assemblies 130, 132 may each include inputs for receiving the fluid level in the tank 108 (e.g., as detected by the tank level sensor 182), the pressure from the fluid source 117 (e.g., as detected by the source line pressure sensor 188), and / or any other suitable information.
[0039] In the exemplary embodiment, the discharge valve control assemblies 130, 132 are operable (e.g., by the discharge valve actuator 133) to move the discharge valves 134, 136 between an open state, a closed state, and a plurality of intermediate states between the open and closed states. The intermediate states may allow for adjustment of the fluid pressure (relative to the fully open state) in the respective lines so that different set pressures are provided to each of the nozzles 122, 126. For example, the nozzle man for the first nozzle 122 may request a different fluid pressure via the interface 154 than the nozzle man for the second nozzle 126. Thus, to vary the pressure in one of the lines, the control system 102 may increase the operating speed of the pump 106 and / or adjust the position of the corresponding discharge valve 134. In an alternative embodiment, the discharge valves 134, 136 may be positioned in either an open state or a closed state (i.e., without the ability to individually adjust the fluid pressure in the lines depending on the intermediate states of the valves). In some such embodiments, the fire suppression system 100 may include a central controller (not shown) that facilitates controlling the operating states of the valves 134, 136 and controlling the operation of the pump 106 based on the operating states of the valves 134, 136. For example, in such embodiments, in response to receiving a request to open the discharge valve, the central controller (not shown) may send a signal to the pump control component 180 to increase the operating speed of the pump 106 in order to maintain consistent fluid pressure in the lines 124, 128.
[0040] 3 is a schematic diagram of an exemplary communication network 190 that may be used in the control system 102 shown in FIG. 2. In the exemplary embodiment, the nozzle components 148, 150, and 151 communicate wirelessly with the corresponding discharge valve control assemblies 130, 132, and 133. Each of the discharge valve control assemblies 130, 132, and 133 is individually communicatively coupled to an equipment component 178. In other embodiments, the communication network 190 may include a communication interface (not shown), such as a communication bus, router, or other suitable network interface, for distributing communication signals between the discharge valve control assembly 130 and the equipment components 178 of the fire suppression system 104. In such an embodiment, each of the discharge valve control assemblies 130, 132, and 133 may be individually coupled to a communication interface, which may communicate with each of the equipment components 178.
[0041] FIG. 4 is a schematic diagram of an alternative communication network 290 that may be used in the control system 102 shown in FIG. 2. The communication network 290 of FIG. 4 is similar to the communication network 190 shown in FIG. 3 in that each of the nozzle components 148, 150 is communicatively coupled to a corresponding discharge valve control assembly 130, 132. However, in the embodiment of FIG. 4, not all of the discharge valve control assemblies 130, 132 are directly communicatively linked to the equipment component 178. Rather, in the embodiment of FIG. 4, the first discharge valve control assembly 130 is communicatively coupled directly to the equipment component 178, and the other discharge valve control assemblies 132, 133 are communicatively coupled piggyback to the first discharge valve control assembly 130. Specifically, communication between the second discharge valve control assembly 132 and the equipment component 178 is routed through the first discharge valve control assembly 130. Communications between the “nth” discharge valve control assembly 133 and the equipment component 178 are sent to the second discharge valve control assembly 132, and from the second discharge valve control assembly 132 to the first discharge valve control assembly 130. In such an embodiment, the discharge valve control assemblies 130, 132, 133 may communicate via wired and / or wireless communication. For example, in an embodiment in which the discharge valve control assemblies 130, 132, 133 are linked via wireless communication, the discharge valve control assemblies 130, 132 may form a wireless mesh network in which one of the discharge valve control assemblies 130, 132, 133 (e.g., the first discharge valve control assembly 130 in FIG. 4 ) functions as a master node and the remaining discharge valve control assemblies 132, 133 function as minor nodes for relaying communications with the master node.
[0042] In other embodiments, at least one of the discharge valve control assemblies 130, 132 may communicate wirelessly directly with the first discharge valve control assembly 130 of the master node. Furthermore, in some embodiments, communication between the discharge valve control assemblies 130, 132, 133 may be facilitated using the CAN communications of the fire suppression apparatus 104, in addition to or in place of other communication methods described herein. Furthermore, in some embodiments, communication between the equipment component 178 and the first discharge valve control assembly 130 may be facilitated using the truck's CAN communications network. For example, without limitation, in some embodiments, pressure measurements detected by pressure sensors 138, 140, 145, 146 (see FIG. 1 ) and / or level information from tank level sensor 182 (see FIG. 2 ) may be transmitted over CAN communications provided by the manufacturer of the fire suppression apparatus 104.
[0043] Figure 5 is a schematic diagram of an alternative fire suppression system 500. Figure 6 is a schematic diagram of an alternative control system 502 that may be used in the fire suppression system 500 of Figure 5.
[0044] The fire suppression system 500 of Figure 5 is substantially the same as the fire suppression system 100 shown in Figure 1, except as noted below. Specifically, in the embodiment of Figure 5, the fire suppression system 500 also includes a pressure regulator 501 for controlling the operation of a pump 506. The pressure regulator 501 includes a controller 503 that controls a prime mover 507. A transceiver 505 is coupled to the fire suppression apparatus 504 and communicates with the pressure regulator 501. In this embodiment, the transceiver 505 may be provided in the fire suppression apparatus 504, or may be provided separately from the fire suppression apparatus 504 and installed in an existing fire suppression apparatus 504 (i.e., retrofit). In such embodiments, the transceiver 505 may be communicatively coupled (e.g., via a wired or wireless communication system such as a CAN) to one or more equipment components 578 of the fire suppression system 504 and may transmit data between the fire suppression system 504 and the nozzles 522, 526 and / or transmit control signals to the fire suppression system 504 and / or the nozzles 522, 526 based on data received from the equipment components 578 (see FIG. 6 ) and / or the nozzle components 548, 550. For example, in some embodiments, the transceiver 505 communicates directly with each of the equipment components 578 and transmits command signals to the equipment components 578. In other embodiments, the transceiver 505 communicates with one or more central controllers (not shown) of the fire suppression system 504, which receive signals from the transceiver 505 and generate control commands for each of the equipment components 578 based on the signals received from the transceiver 505. System 500 further includes a tank 508 and a source 517 that are identical to tank 108 and source 117 shown in FIG.
[0045] In some embodiments, the transceiver 505 may be integrated into the control loop (see FIG. 5 ) of the fire suppression system 504 such that the components of the fire suppression system 504 (e.g., prime mover 507, pump 506, valves 512, 516, 520, 534, 536, etc.) are automatically controlled based on data and / or signals received by the transceiver 505. In other embodiments, the transceiver 505 may not be integrated, or may only be partially integrated, with the control loop of the fire suppression system 504. In such embodiments, the fire suppression system 504 may display data (e.g., nozzle pressure, nozzle flow rate, etc.) on a display (not shown) on the fire suppression system 504, for example, to an operator or engineer who manually adjusts the components of the fire suppression system 504 to achieve desired fluid parameters, as described in more detail with respect to the embodiment of FIG. 7 . Additionally, in some embodiments, the transceiver 505 may be sold in combination (e.g., as a kit or assembly) with one or more nozzles 522, 526 (e.g., a first nozzle 522 and / or a second nozzle 526) that are paired with the transceiver 505 and capable of transmitting data and / or control signals between the fire suppression system 504 and the nozzles 522, 526.
[0046] In the exemplary embodiment, fire suppression system 504 does not include discharge valve control assemblies 130, 132 (see FIG. 1 ) in communication with nozzle components 548, 550. Rather, in the exemplary embodiment, fire suppression system 504 includes a transceiver 505, and nozzle components 548, 550 each communicate wirelessly with transceiver 505. In an alternative embodiment, fire suppression system 504 may include discharge valve control assemblies 530, 532 that are substantially similar to assemblies 130, 132 shown in FIG. 1 , except that they are in communication with controller 503 and prime mover 507, as shown in FIG. 5 .
[0047] In the exemplary embodiment, prime mover 507 controls the operation of pump 506. For example, prime mover 507 may include a pump motor (not shown). Controller 503 receives signals from transceiver 505 and controls prime mover 507, such that operation of pump 506 is based at least in part on the signals received from transceiver 505. That is, in the exemplary embodiment, in contrast to the embodiment of FIG. 1 , control system 502 is configured to automatically control pump 506 without manual control by an operator of fire suppression apparatus 504.
[0048] 6, in the exemplary embodiment, first nozzle component 548 includes a transceiver 552 for providing communication between first nozzle component 548 and a transceiver 505 of fire suppression system 504. Transceiver 505 of fire suppression system 504 is also communicatively coupled to equipment components 578 of fire suppression system 504. Equipment components 578 in FIG. 6 include similar equipment components 578 to those included in the embodiment illustrated in FIG. 3, such as pressure regulator 501, pump pressure sensor 584, source line pressure sensor 588, source valve actuator 586, recirculation valve actuator 589, supply valve actuator 591, and tank level sensor 582. However, in the exemplary embodiment of FIG. 6, equipment components 578 communicating via transceiver 505 also include first discharge valve actuator 533 and second discharge valve actuator 535. The first nozzle component 548 may also include an interface 554, a nozzle display 556, an indicator 558, a nozzle pressure sensor 560, a locator beacon 562, and a nozzle component controller 564, which are substantially the same as those described with respect to the first nozzle component 148 (see FIG. 2).
[0049] In some embodiments, the fire suppression apparatus transceiver 505 and / or equipment components 578 may include a communications interface, such as a communications bus, router, or other suitable network interface, for distributing communication signals between the fire suppression apparatus transceiver 505 and the equipment components 578 of the fire suppression apparatus 504. Communication between the fire suppression apparatus transceiver 505 and the equipment components 578 may be facilitated by individual inputs to the transceiver 505, analog inputs, CAN communication inputs, and / or wireless connections.
[0050] In some embodiments, the fire suppression system transceiver 505 is part of a controller (not shown) for the fire suppression system 504. In some such embodiments, the controller includes a processor and memory (not shown), and the controller monitors the tank level based on readings from the tank level sensor 582, monitors the suction pressure from the truck based on readings from the source line pressure sensor 588, monitors the pressure (e.g., outlet pressure) of the pump 506 based on one or more pump pressure sensors 584, sends or receives pressure requests from the pressure regulator 501 to maintain varying pressures in the pump 506 necessary to properly pump the hose lines 544 at safe pressures for the nozzles 522, 526, and provides open / close signals to the valve actuators 533, 535, 586, 589, 591 during operation and / or sets the valve positions to intermediate states to control the pressure in the respective lines based on the pressures sensed by the pressure sensors 545, 546. Additionally, although the transceiver 505 is described herein as a single unit, in other embodiments, the control system 502 may include multiple transceivers 505, controllers, and / or nodes on a network that collectively perform the functions of the fire suppression device transceiver 505 described herein.
[0051] In some embodiments, the fire suppression system transceiver 505 controls the discharge valve actuators 533, 535 and / or the pressure regulator 501 based on the actual pressure sensed at the nozzle and the user-requested fluid pressure at the corresponding nozzle. For example, a nozzleman may first request charging of the hose line 544 using the interface 554 of the nozzle component 548. In response, the nozzle transceiver 552 may send a signal to the fire suppression system transceiver 505 indicating the request, and the fire suppression system transceiver 505 may send a signal to the first discharge valve actuator 533 to open the first discharge valve 534, i.e., to adjust the valve 534 based on a predetermined starting pressure setting. Once the hose line 544 of the first fluid line 524 is charged, the nozzle pressure sensor 560 may detect the fluid pressure at the nozzle 522 and transmit the detected pressure to the transceiver 505. If there is a discrepancy between the predetermined set pressure and the actual pressure sensed by the nozzle pressure sensor 560 (e.g., due to hose friction losses), the transceiver 505 may adjust the position of the corresponding discharge valve 534 and / or adjust the operation of the pump 506 (via the pump control component 580) to facilitate reducing the difference between the set pressure and the sensed pressure. The transceiver 505 may also learn over time whether a higher pressure is consistently needed and adjust the initial starting set pressure based on data from a historical average of usage. Additionally, the control system 102 of FIG. 2 may also adjust the settings of the corresponding discharge valves 134, 136 and / or pump 106 to provide the desired fluid pressure to the nozzles 122, 126 in substantially the same manner as described with respect to FIG. 6.
[0052] Figure 7 is a schematic diagram of another alternative fire suppression system 700. Fire suppression system 700 of Figure 7 is substantially similar to fire suppression system 500 of Figure 5, except as noted below. Specifically, in the embodiment of Figure 7, fire suppression apparatus 704 includes a panel display 707 in communication with transceiver 505. Panel display 707 may communicate information in visual and / or audio format provided by transceiver 705 and received from other equipment components, such as nozzle components 748, 750 and / or equipment component 578 of fire suppression apparatus 504 (see Figure 6).
[0053] During operation, an engineer may control the operation of pump 706, discharge valves 734, 736, and / or any equipment components 778 of fire suppression apparatus 704 based on information displayed on panel display 707. For example, panel display 707 may display fluid pressure detected by pressure sensors in each of nozzle components 748, 750, and the engineer may manually adjust control of pump 706 or other equipment components, such as equipment component 578 (see FIG. 6 ), based on the detected fluid pressure. In some embodiments, panel display 707 includes an operator interface for receiving controls from the engineer. In other embodiments, fire suppression apparatus 704 includes a control panel (not shown) separate from panel display 707.
[0054] In other embodiments, the fire suppression apparatus 104 of FIG. 1 may also include a panel display 707 that operates substantially similarly to the panel display 707 described with respect to FIG. 7, except that it is in communication with the discharge valve control assemblies 130, 132 of FIG. 1.
[0055] Figure 8 is a flow diagram of an exemplary method 800 of operating a fire suppression system. The method may be implemented using any one of the fire suppression systems 100, 500, 700 of Figures 1, 5, and 7 and the control system 202, 502 of Figure 2 or 6, respectively. In some embodiments, the method of Figure 8 provides a rapid attack fire suppression method in which a nozzleman may be deployed to an attack location, request fluid, and begin discharging from each nozzle 122, 126 without requiring intervention or control by the operator of the fire suppression apparatus 104, as described with respect to the embodiment of Figure 5.
[0056] In an exemplary method, upon first arriving at a scene (e.g., a fire scene), the control system 102 initiates a fire suppression operation 802. In some embodiments, the control system 102 may automatically determine to initiate a fire suppression operation 802 in response to detecting a change in the operational state of the fire suppression apparatus 104. For example, in some such embodiments where the fire suppression apparatus 104 is a fire truck, the control system 102 may initiate a fire suppression operation 802 when the system detects that the vehicle has shifted between park and drive gear, or that the vehicle has shifted into any other gear commonly used for fire suppression operations.
[0057] In response to the fire suppression operation 802 being initiated, the control system 102 opens 804 the tank supply valve 116 (see FIG. 1 ) to allow fluid flow from the tank 108 to the pump 106. In some embodiments, referring to FIG. 1 , the recirculation valve 116 also opens automatically to bleed any residual air in the pump 106 out of the pump 106 and provide cooling to the pump 106 during operation. In other embodiments, the residual air may be bled from the pump 106 and the pump 106 may be cooled using an optional valve / line such as the tank fill valve (not shown), or a small solenoid controlled valve such as a pump cooling line (not shown) separate from the tank fill valve.
[0058] In an exemplary method, after the supply valve 116 is opened 804, the control system 102 provides 806 a signal to the nozzle components 148, 150 to indicate that the fire suppression system 104 is ready to receive a demand for water at the nozzles 122, 126 (i.e., that the respective hose lines 144 are ready to be charged). In some embodiments, before providing 808 an indication that the lines 144 are ready to be charged, the control system 102 may first initiate operation of the pump 106 and perform a pressure check (e.g., as described above with respect to FIGS. 1 and 2 ) to determine whether a predetermined fluid pressure is being generated by the pump 106. Such a check may be particularly suitable for embodiments in which the pressure of the pump 106 is manually controlled and maintained (e.g., by an engineer). In other embodiments, the control system 102 automatically adjusts control of the pump 106 and the discharge valves 134, 136. In some such embodiments, it may not be necessary to perform a pressure check before signaling to the nozzleman that the line 144 is ready to be charged, since the pump 106 and valves 134, 136 may be controlled to provide at least a minimum or starting fluid pressure to the line 144 in response to receiving a request to charge the line 144 from the nozzleman at the nozzle components 148, 150.
[0059] In an exemplary method, the control system 102 receives 808 a request from at least one of the nozzle components 148, 150 to charge the corresponding line 144. In some embodiments, the request to charge the line 144 may include a user-requested fluid pressure to be provided to the line. In other embodiments, a predetermined starting fluid set pressure may be determined for all or more of the nozzle components 148, 150. In other embodiments, the initial set pressure for each nozzle component 148, 150 may be nozzle 122, 126-specific.
[0060] In the exemplary method, the control system 102 controls 810 the operation of the pump 106 and / or the discharge valves 134, 136 to supply fluid to the nozzles 122, 126 at a starting fluid set pressure. In embodiments where the set pressures differ between the nozzles 122, 126, the pump 106 is controlled 810 to provide the highest set pressure among the different nozzle components 148, 150. The control system 102 is further configured to provide closed-loop updates to the control of the pump 106 and / or the discharge valves based on the detected fluid pressure measured by the nozzle pressure sensors 160s.
[0061] In the exemplary system, the control system 102 may also prevent an engineer from manually adjusting the pump 106 controls to reduce the set pressure below the determined fluid set pressure for each of the hose lines and nozzle components. For example, if a nozzleman requests 60 psi of fluid pressure at a nozzle component, the control system 102 controls the operation of the pump 106 and the discharge valves 134, 136 to provide fluid to the corresponding nozzle at 60 psi. If an engineer of the fire suppression system 104 adjusts the pump 106 controls in a way that limits the pump 106 to providing only 55 psi to the corresponding nozzle, the control system 102 may reject or prevent the engineer's adjustment and provide an error message to the engineer, notifying them that they are making an unsafe adjustment. If a change in the fire suppression system 100 (e.g., a change in source pressure or tank 108) causes the system to operate below the determined fluid set pressure, the control system 102 may, for example, audibly, visually, and / or tactilely alert the engineer that the lines are under-pressurized. If the system 102 notices a complete loss of inlet pressure and the tank supply valve 116 is closed, the system 102 may open the tank supply valve 116 and resume flow while alerting the operator to close the source valve 120. If the tank supply valve 116 is closed and the system 102 has achieved significant discharge pressure, the system 102 may assume a draft condition (i.e., a condition in which the pump 106 creates a negative pressure differential in the source line 118). If the system loses discharge pressure, the system 102 may open the tank supply valve 116 and alert the operator to close the source valve 120.
[0062] Exemplary embodiments of systems and methods for controlling a fire suppression apparatus are described in detail above. The methods and apparatus are not limited to the specific embodiments described herein; rather, system components and / or method steps may be utilized separately and independently of other components and / or steps described herein. For example, the systems and methods may be used in combination with other fire suppression systems and methods and are not limited to practice with only the fire suppression apparatus described herein. Rather, the exemplary embodiments may be implemented and utilized in connection with many other fire suppression apparatuses.
[0063] Although specific features of various embodiments may be shown in some drawings and not in others, this is for convenience only. Moreover, references to "one embodiment" in the above description are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. In accordance with the principles of the present disclosure, any feature of a drawing may be referenced and / or claimed in combination with any feature of any other drawing.
[0064] This written description uses examples to disclose the invention, including the best mode, and also enables any person skilled in the art to practice the invention, including making and using any devices or systems, and performing any methods incorporated therein. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if the examples include equivalent structural elements that do not differ substantially from the literal language of the claims.
Claims
1. A pump and a nozzle for directing fluid flow from the pump toward a target area; a nozzle component coupled to the nozzle, the nozzle component including a first transceiver and an indicator; a fluid line connecting the pump to the nozzle; 1. A discharge valve control assembly comprising: a discharge valve for controlling fluid flow between the pump and the nozzle; a pressure sensor coupled to the fluid line between the pump and the discharge valve; a second transceiver for providing communication between the nozzle component and the discharge valve control assembly; and receiving a request to charge a hose portion of the fluid line; in response to receiving the request, determining whether to open the discharge valve based on the fluid pressure detected by the pressure sensor; the discharge valve control assembly configured as follows: A fire extinguishing system comprising:
2. the request to charge the hose portion of the fluid line is transmitted from the nozzle component to the discharge valve control assembly by the first transceiver and the second transceiver. The fire suppression system of claim 1 .
3. the nozzle component further includes a display and an interface, the interface configured to receive user input, and the nozzle component transmitting the request to charge the hose portion of the fluid line in response to receiving the user input at the interface.
3. The fire suppression system of claim 2.
4. the nozzle component is paired with the discharge valve control assembly via communication between the first transceiver and the second transceiver.
3. The fire suppression system of claim 2.
5. the discharge valve control assembly is communicatively connected to at least one equipment component of the fire suppression system, the at least one component including at least one of a pump control component, a tank sensor coupled to a tank of the fire suppression system, a source valve actuator, a recirculation valve actuator, and a tank supply valve actuator; The fire suppression system of claim 1 .
6. the discharge valve control assembly being communicatively connected to the one or more pieces of equipment via a controller area network ("CAN") of the fire suppression system; 6. The fire suppression system of claim 5.
7. the nozzle is a first nozzle, the nozzle component is a first nozzle component, the fluid line is a first fluid line, the discharge valve assembly is a first discharge valve control assembly, and the fire suppression system comprises: a second fluid line connecting the pump to a second nozzle; a second discharge valve control assembly communicatively connected to the at least one device component; Further provided with 6. The fire suppression system of claim 5.
8. the first discharge valve control assembly and the second discharge valve control assembly are each directly and communicatively coupled to the at least one device component; 8. The fire suppression system of claim 7.
9. the second discharge valve control assembly is indirectly connected to the at least one equipment component via the first discharge valve control assembly; 8. The fire suppression system of claim 7.
10. further comprising a second pressure sensor coupled between the discharge valve and the nozzle; The fire suppression system of claim 1 .
11. The discharge valve control assembly further includes a controller including a processor and a memory that stores commands and a predefined threshold pressure, the processor configured to perform the steps of receiving the request to charge the hose section and determining whether to open the discharge valve, the processor further comprising: comparing the detected fluid pressure to the predetermined limit pressure; opening the discharge valve when the detected fluid pressure equals or exceeds the predetermined limit pressure; sending an alert to the nozzle component if the detected fluid pressure is below the predetermined limit pressure; It is configured as follows: The fire suppression system of claim 1 .
12. 1. A discharge valve control assembly for use in a fire suppression system, comprising: a discharge valve for controlling fluid flow through a fluid line extending from the pump to a nozzle of the fire suppression system; a pressure sensor coupled to the fluid line upstream of the discharge valve; a transceiver for providing communication with a nozzle component coupled to the nozzle; the discharge valve control assembly comprising: receiving a request from the nozzle component to charge a hose portion of the fluid line; in response to receiving the request, determining whether to open the discharge valve based on the fluid pressure detected by the pressure sensor; The discharge valve control assembly is configured as follows.
13. the discharge valve control assembly is communicatively connected to at least one equipment piece of the fire suppression system, the at least one equipment piece including at least one of a pump control component, a tank sensor that detects a fluid level in a tank of the fire suppression system, a source valve actuator, a recirculation valve actuator, and a tank supply valve actuator; The discharge valve control assembly of claim 12.
14. the discharge valve control assembly is communicatively connected to an additional discharge valve control assembly of the fire suppression system, the additional discharge valve control assembly being indirectly connected to the at least one equipment piece via the discharge valve control assembly; 14. The discharge valve control assembly of claim 13.
15. a processor and a memory that stores a command and a predefined threshold pressure, the processor being configured to perform the steps of receiving the request to charge the hose section and determining whether to open the discharge valve, the processor further comprising: comparing the detected fluid pressure to the predetermined limit pressure; opening the discharge valve when the detected fluid pressure equals or exceeds the predetermined limit pressure; sending an alert to the nozzle component if the detected fluid pressure is below the predetermined limit pressure; It is configured as follows: The discharge valve control assembly of claim 12.
16. a second pressure sensor coupled to the fluid line between the discharge valve and the nozzle; The discharge valve control assembly of claim 12.
17. the discharge valve control assembly is wirelessly paired with the nozzle component; The discharge valve control assembly of claim 12.
18. 1. A method of operating a fire suppression system, comprising: sending a first signal from a transceiver of a fire truck of the fire suppression system to a nozzle component indicating that a hose portion of a fluid line is ready to be charged; receiving, at said transceiver, a second signal from said nozzle component including a request to charge said hose section; determining to charge the fluid line based on a fluid pressure detected by a pressure sensor and a predefined minimum pressure stored in a memory, wherein the pressure sensor is disposed in the fluid line upstream of a discharge valve; automatically controlling the discharge valve to open to charge the hose section in response to the determination. A method comprising:
19. detecting a change in the operating state of the fire truck; automatically opening a tank supply valve coupled to a tank supply line extending between a fluid tank and a pump of the fire suppression system in response to the detection; and transmitting the first signal automatically in response to opening the tank supply valve. further comprising:
20. The method of claim 18.
20. The second signal includes a user requested fluid pressure, and the method further comprises: receiving a request at a control panel of the fire truck to change the set pressure of the pump of the fire suppression system; rejecting the request based on a determination that the change in the set pressure of the pump would provide a fluid pressure to the nozzle that is less than the fluid pressure requested by the user. Including, 20. The method of claim 18.