Abstract: Methods, systems, and computer-readable storage media for providing high-resolution assessment of the condition of pipes of a fluid distribution down to the individual pipe stick. An acoustic sensor is placed in acoustical communication with a pipe at one end of a target segment. An acoustical wave is generated in the pipe at a first out-of-bracket excitation location while signal data is recorded from the acoustic sensor. Timing information regarding the arrival at the acoustic sensor of reflections of the acoustic wave from pipe joints in the target segment is extracted from the recorded signal data, and a time delay between reflections from consecutive pipe joints is computed. An acoustic propagation velocity in a pipe stick between the consecutive pipe joints is then computed based on the time delay and a length of the pipe stick. A condition of the pipe stick is determined based on the computed acoustic propagation velocity.

Abstract: A nozzle cap for a fire hydrant includes a cap body defining a cap axis and comprising an inner housing defining an inner fastener hole; and an outer housing defining an outer fastener hole, the outer housing axially aligned with and contacting the inner housing; and a fastener defining a head and a shaft, the shaft engaging each of the outer fastener hole and the inner fastener hole to secure the outer housing with the inner housing; a disc spring arranged on the shaft and positioned between the cap body and the head of the fastener; and a compression limiter disposed within the outer fastener hole and defining a limiter opening, wherein the shaft of the fastener further engages the limiter opening.

Abstract: A nozzle cap for a fire hydrant includes a cap cover comprising a metal material; and a cap body defining a cap axis, the cap body comprising: an inner housing comprising a metal material; and an outer housing comprising a non-metal material, the outer housing disposed axially between the inner housing and the cap cover, the outer housing comprising a substantially circumferential wall, the substantially circumferential wall defining a cavity between the inner housing and the cap cover, wherein a first end of the substantially circumferential wall engages the inner housing.

Abstract: Methods, systems, and computer-readable storage media for determining the material of pipe in a non-invasive manner. Two acoustic sensors are attached near either end of a pipe segment. An acoustical wave is generated in the pipe by exciting the pipe system at an out-of-bracket location while signal data from the first and second acoustic sensors is recorded. A speed of sound in the pipe segment and/or an attenuation factor for the pipe segment are computed from the signal data, and a material of the pipe is determined based on the computed speed of sound in the pipe segment and a relationship between speeds of sound in pipes and the materials of the pipes and/or the computed attenuation factor for the pipe segment and a relationship between attenuation factors of pipes and the materials of the pipes.

Abstract: Apparatuses, methods, and systems for accurate measurement of the bulk modulus of a fluid in a fluid distribution system. An apparatus comprises a pipe, a first endcap, and a second endcap defining a cylindrical cavity, a means for filling the cylindrical cavity with a fluid sample, and a vibrational sensor coupled to an end plate of the second endcap and communicatively connected to a water property measurement system. The vibrational sensor is operable to, subsequent to the filling of the cylindrical cavity with the fluid sample, send a signal representative of sensed vibrations in the end plate of the second endcap to the water property measurement system while an end plate of the first endcap is excited. The water property measurement system computes a frequency response function from the signal and determines a bulk modulus value for the fluid sample based on the frequency response function.

Abstract: Methods, systems, and computer-readable storage media for accurate time delay estimation using coherent averaging. A plurality of out-of-bracket acoustical impulses are generated in a pipe segment of a fluid distribution system. Signal data representing the acoustical impulses sensed at two locations along the pipe segment are recorded. Precise timings for the generation of the acoustical impulses are obtained, and the acoustical impulses in the signal data recorded from the first location are averaged based on the precise timings to produce a near-sensor average impulse. Similarly, the acoustical impulses in the signal data recorded from the second location are averaged based on the same precise timings to produce a far-sensor average impulse. A time delay between arrival of the plurality of out-of-bracket acoustical impulses at the first and second locations is estimated from the timing of the near-sensor average impulse and the far-sensor average impulse.

Abstract: A nozzle cap includes a cap body defining a cap axis, the cap body defining a circumferential wall extending circumferentially around the cap axis; and a vibration sensor including a shaft, the shaft defining a first end and a second end, the first end attached to the circumferential wall, the cap axis positioned closer to the second end than to the first end.

Abstract: A nozzle cap for a fire hydrant includes a cap cover comprising a metal material; and a cap body defining a cap axis, the cap body comprising: an inner housing comprising a metal material; and an outer housing comprising a non-metal material, the outer housing disposed axially between the inner housing and the cap cover, the outer housing comprising a substantially circumferential wall, the substantially circumferential wall defining a cavity between the inner housing and the cap cover, wherein a first end of the substantially circumferential wall engages the inner housing.

Abstract: Example aspects of a nozzle cap for a fire hydrant and a method of detecting a leak in a fluid system are disclosed. The nozzle cap for a fire hydrant can include an outer housing defining a first end, a second end opposite the first end, and a substantially circumferential wall extending from the first end to the second end; an antenna coupled to the substantially circumferential wall of the outer housing; a cap cover coupled to the outer housing at the first end; and an inner housing coupled to the outer housing at the second end.

Abstract: A sensor system can include a sensor module including a vibration sensor; a processor module including a power supply and a processor PCB, the processor module connected in electrical communication with the sensor module by a first cable; and an antenna module including an antenna, the antenna module connected in electrical communication with the processor module by a second cable.

Abstract: Methods, systems, and computer-readable storage media for performing high-resolution assessment of the condition of pipes of a fluid distribution system using in-bracket excitation. Acoustical impulses are generated in a pipe at two excitation locations along the pipe while signal data is recorded from two acoustic sensors, at least one of the excitation locations being located in-bracket of the two acoustic sensors. A first time delay between the arrival of the acoustical impulses at the two acoustic sensors is computed from the signal data recorded during generation of the impulses at the first excitation location, and a second time delay between the arrival of the impulses at the two sensors is computed from the signal data recorded during generation of the impulses at the second excitation location.

Abstract: Methods, systems, and computer-readable storage media for providing high-resolution assessment of the condition of pipes of a fluid distribution down to the individual pipe stick. An acoustic sensor is placed in acoustical communication with a pipe at one end of a target segment. An acoustical wave is generated in the pipe at a first out-of-bracket excitation location while signal data is recorded from the acoustic sensor. Timing information regarding the arrival at the acoustic sensor of reflections of the acoustic wave from pipe joints in the target segment is extracted from the recorded signal data, and a time delay between reflections from consecutive pipe joints is computed. An acoustic propagation velocity in a pipe stick between the consecutive pipe joints is then computed based on the time delay and a length of the pipe stick. A condition of the pipe stick is determined based on the computed acoustic propagation velocity.

Abstract: Example aspects of a nozzle cap for a fire hydrant and a method for manufacturing a nozzle cap to detect leaks in a fluid system are disclosed. The nozzle cap for a fire hydrant can comprise a cap body, the cap body comprising an inner housing and an outer housing, the outer housing defining a cavity; a vibration sensor received within the cavity and configured to detect leaks in a fluid system connected to the fire hydrant; and a metal insert contacting the vibration sensor and the inner housing.

Abstract: A nozzle cap includes a cap body defining a cap axis, the cap body defining a circumferential wall extending circumferentially around the cap axis; and a vibration sensor including a shaft, the shaft defining a first end and a second end, the first end attached to the circumferential wall, the cap axis positioned closer to the second end than to the first end.

Abstract: Apparatuses, methods, and systems for accurate measurement of the bulk modulus of a fluid in a fluid distribution system. An apparatus comprises a pipe, a first endcap, and a second endcap defining a cylindrical cavity, a means for filling the cylindrical cavity with a fluid sample, and a vibrational sensor coupled to an end plate of the second endcap and communicatively connected to a water property measurement system. The vibrational sensor is operable to, subsequent to the filling of the cylindrical cavity with the fluid sample, send a signal representative of sensed vibrations in the end plate of the second endcap to the water property measurement system while an end plate of the first endcap is excited. The water property measurement system computes a frequency response function from the signal and determines a bulk modulus value for the fluid sample based on the frequency response function.

Abstract: A hydrant assembly includes a fire hydrant including a barrel, the barrel defining a barrel axis extending from a top barrel end of the barrel to a bottom barrel end of the barrel; and a vibration sensor enclosed within the fire hydrant, the vibration sensor defining a sensor axis extending from a first sensor end of the vibration sensor to a second sensor end of the vibration sensor, the sensor axis defining an angle relative to the barrel axis, the angle less than ninety degrees.

Abstract: A hydrant assembly includes a fire hydrant including a barrel, the barrel defining a barrel axis extending from a top barrel end of the barrel to a bottom barrel end of the barrel; and a vibration sensor enclosed within the fire hydrant, the vibration sensor defining a sensor axis extending from a first sensor end of the vibration sensor to a second sensor end of the vibration sensor, the sensor axis defining an angle relative to the barrel axis, the angle less than ninety degrees.

Abstract: Example aspects of a nozzle cap for a fire hydrant and a method for manufacturing a nozzle cap to detect leaks in a fluid system are disclosed. The nozzle cap for a fire hydrant can comprise a cap body, the cap body comprising an inner housing and an outer housing, the outer housing defining a cavity; a vibration sensor received within the cavity and configured to detect leaks in a fluid system connected to the fire hydrant; and a metal insert contacting the vibration sensor and the inner housing.

Abstract: Methods, systems, and computer-readable storage media for performing high-resolution assessment of the condition of pipes of a fluid distribution system using in-bracket excitation. Acoustical impulses are generated in a pipe at two excitation locations along the pipe while signal data is recorded from two acoustic sensors, at least one of the excitation locations being located in-bracket of the two acoustic sensors. A first time delay between the arrival of the acoustical impulses at the two acoustic sensors is computed from the signal data recorded during generation of the impulses at the first excitation location, and a second time delay between the arrival of the impulses at the two sensors is computed from the signal data recorded during generation of the impulses at the second excitation location.

Abstract: Methods, systems, and computer-readable storage media for accurate time delay estimation using coherent averaging. A plurality of out-of-bracket acoustical impulses are generated in a pipe segment of a fluid distribution system. Signal data representing the acoustical impulses sensed at two locations along the pipe segment are recorded. Precise timings for the generation of the acoustical impulses are obtained, and the acoustical impulses in the signal data recorded from the first location are averaged based on the precise timings to produce a near-sensor average impulse. Similarly, the acoustical impulses in the signal data recorded from the second location are averaged based on the same precise timings to produce a far-sensor average impulse. A time delay between arrival of the plurality of out-of-bracket acoustical impulses at the first and second locations is estimated from the timing of the near-sensor average impulse and the far-sensor average impulse.