ELECTROFUSION PIPE FITTINGS, METHODS, AND SYSTEMS
20180009174 · 2018-01-11
Inventors
Cpc classification
F16L2201/30
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
B29C66/1122
PERFORMING OPERATIONS; TRANSPORTING
F16L47/03
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
B29C66/71
PERFORMING OPERATIONS; TRANSPORTING
B29C66/5221
PERFORMING OPERATIONS; TRANSPORTING
B29C66/71
PERFORMING OPERATIONS; TRANSPORTING
B29K2023/065
PERFORMING OPERATIONS; TRANSPORTING
B29C65/8246
PERFORMING OPERATIONS; TRANSPORTING
B29C66/52296
PERFORMING OPERATIONS; TRANSPORTING
B29K2023/065
PERFORMING OPERATIONS; TRANSPORTING
B29C65/3468
PERFORMING OPERATIONS; TRANSPORTING
B29C65/3432
PERFORMING OPERATIONS; TRANSPORTING
B29C66/5223
PERFORMING OPERATIONS; TRANSPORTING
International classification
Abstract
This disclosure is directed to pipe fittings, systems, and methods. Specifically, this disclosure provides pipe fittings with pairs of circumferential sealing zones and a pressure-testing chamber between the sealing zones. This disclosure also provides pipe fittings with sensors for detecting a breach in one or more sealing zones. The disclosure also provides data trackers for collecting information about the pressure-testing chamber and/or breaches in the sealing zones. Finally, this disclosure provides a dormant power source that becomes powered upon an aqueous breach of one or more sealing zones.
Claims
1. A pipe fitting comprising a hollow tubular sleeve comprising a first open end and a second open end, wherein the first open end is configured to receive a first pipe and the second open end is configured to receive a second pipe; a first pair of circumferential sealing zones proximal to the first open end of the sleeve comprising a first inner circumferential sealing zone and a first outer circumferential sealing zone, wherein the first inner circumferential sealing zone comprises a first inner coil to form a seal with an inserted pipe; a first circumferential pressure chamber arranged between the first inner circumferential sealing zone and the first outer circumferential sealing zone, wherein the first circumferential pressure chamber comprises a first inlet; and a first valve and current connector fluidically coupled to the first inlet and electronically connected to the first inner coil.
2. The pipe fitting of claim 1, further comprising a second pair of circumferential sealing zones proximal to the second open end of the sleeve comprising a second inner circumferential sealing zone and a second outer circumferential sealing zone, wherein the second inner circumferential sealing zone comprises a second inner coil to form a seal with an inserted pipe; a second circumferential pressure chamber arranged between the second inner circumferential sealing zone and the second outer circumferential sealing zone, wherein the second circumferential pressure chamber comprises a second inlet; and a second valve and current connector fluidically coupled to the second inlet and electronically connected to the second inner coil.
3. The pipe fitting of claim 1, wherein the first outer circumferential sealing zone comprises an indent sized and shaped to hold an O-ring and having a depth sufficient to enable the O-ring to make a seal with an inserted pipe.
4. The pipe fitting of claim 3, wherein the depth of the indent narrows longitudinally away from the first circumferential pressure-testing chamber along the inner surface of the fitting.
5. The pipe fitting of claim 4, wherein the indent further comprises a ridge.
6. The pipe fitting of any one of claims 3-5, further comprising an O-ring disposed in the indent.
7. The pipe fitting of claim 1, wherein the first valve and current connector further comprises a shell.
8. The pipe fitting of claim 1, wherein the first outer circumferential sealing zone comprises a first outer coil to form a seal with an inserted pipe.
9. The pipe fitting of claim 8, wherein the first valve and current connector is further electronically connected to the first outer coil.
10. A pipe fitting comprising a hollow tubular sleeve comprising a first open end and a second open end, wherein the first open end is configured to receive a first pipe and the second open end is configured to receive a second pipe; a first pair of circumferential sealing zones proximal to the first open end of the sleeve comprising a first inner circumferential sealing zone and a first outer circumferential sealing zone, wherein the first inner circumferential sealing zone comprises a first inner coil to form a seal with an inserted pipe; a first circumferential pressure chamber arranged between the first inner circumferential sealing zone and the first outer circumferential sealing zone, wherein the first circumferential pressure chamber comprises a first inlet; and a sensor fluidically coupled to the first circumferential pressure-testing chamber.
11. The pipe fitting of 10, wherein the first outer circumferential sealing zone comprises a first outer coil to form a seal with an inserted pipe.
12. The pipe fitting of claim 10, wherein the sensor is configured to detect a breach of the first inner circumferential sealing zone or the first outer circumferential sealing zone.
13. The pipe fitting of claim 10, wherein the sensor is selected from the group consisting of an acoustic sensor, a vibration sensor, an air-gas ratio sensor, a mass flow sensor, an O2 sensor, a CO2 sensor, a CO sensor, an H2 sensor, a chemical transistor, a chemical resistor, an ion sensor, a galvanometer, a flow sensor, a mass flow rate sensor, a strain gauge, a piezoelectric sensor, a heat flux sensor, a thermistor, and a thermocouple.
14. The pipe fitting of claim 13, wherein the sensor is a thermocouple.
15. The pipe fitting of any one of claims 10 to 14, further comprising a data tracker coupled to the sensor.
16. The pipe fitting of claim 15, wherein the data tracker is an RFID chip.
17. The pipe fitting of any one of claims 10 to 16, further comprising a power source electronically coupled to the sensor.
18. The pipe fitting of claim 15, wherein the power source is a battery.
19. The pipe fitting of any one of claims 10 to 18, further comprising a dormant battery disposed in at least a portion of the first circumferential pressure-testing chamber, the dormant batter comprising a dry electrolyte; an anode; a cathode; and circuitry electronically coupling the anode, the cathode, and the sensor.
20. A pipe fitting comprising a hollow tubular sleeve comprising a first open end and a second open end, wherein the first open end is configured to receive a first pipe and the second open end is configured to receive a second pipe; a first pair of circumferential sealing zones proximal to the first open end of the sleeve comprising a first inner circumferential sealing zone and a first outer circumferential sealing zone, wherein the first inner circumferential sealing zone comprises a first inner coil to form a seal with an inserted pipe; a first circumferential pressure chamber arranged between the first inner circumferential sealing zone and the first outer circumferential sealing zone, wherein the first circumferential pressure chamber comprises a first inlet; a data tracker disposed at or proximal to the exterior of the sleeve; and a dormant battery disposed in at least a portion of the first circumferential pressure chamber, the dormant batter comprising a dry electrolyte; an anode; a cathode; and circuitry electronically coupling the anode, the cathode, and the data tracker.
21. The pipe fitting of claim 20, wherein the first outer circumferential sealing zone comprises a first outer coil to form a seal with an inserted pipe.
22. The pipe fitting of any one of claim 20 or 21, wherein the dormant battery further comprises a stabilizer.
23. The pipe fitting of claim 22, wherein the stabilizer is butylated hydroxytoluene.
24. The pipe fitting of any one of claims 20 to 23, wherein the data tracker is an RFID chip.
25. The pipe fitting of any one of claims 20 to 24, wherein the dry electrolyte is selected from the group consisting of silver nitrate, nitric acid, sodium chloride, potassium hydroxide, and sodium hydroxide.
26. The pipe fitting of any one of claims 20 to 25, further comprising a sensor electronically coupled to the data tracker.
27. The pipe fitting of claim 26, wherein the sensor is a thermocouple.
28. The pipe fitting of any one of claims 1 to 27, wherein the fitting comprises polyethylene.
29. The pipe fitting of claim 28, wherein the polyethylene is HDPE.
Description
BRIEF DESCRIPTION OF THE FIGURES
[0027]
[0028]
[0029]
[0030]
DETAILED DESCRIPTION
[0031] As used herein, the terms “a” or “an” mean one or more unless these terms are otherwise limited by their use.
[0032] As used herein, the term “about” means±10% of a stated value.
[0033] The present disclosure provides pipe fittings with various features. The present disclosure provides a fitting that is tubular (straight or bent, such as straight sleeve or elbow joint) to join at least two pipes. The fitting comprises weldable plastic. In certain embodiments, the fitting comprises PE or PP. In some embodiments, the fitting comprises HDPE. The main tubular fitting part is referred to as a “sleeve.” In some embodiments, at least one open end of the sleeve has two circular or circumferential sealing zones relative to the axial center of the sleeve—an inner sealing zone and an outer sealing zone. The sealing zones form a pair of circular or circumferential seals between an inserted pipe and the sleeve. The sealing zones are proximal to the end of the fitting and situated so that they can weld an inserted pipe. In some embodiments, each open end of the fitting comprises two circumferential sealing zones. In some embodiments, one or more open ends of the fitting comprises an inner sealing zone and an outer O-ring sealing zone, which is described in greater detail below.
[0034] The sleeve further comprises an annular space between the inner and outer sealing zones along the inner circumference of the sleeve. This space functions as a pressure-testing chamber for testing the inner seal formed between an inserted pipe and the fitting at the inner sealing zone and the outer seal formed between an inserted pipe and the fitting at the outer sealing zone. The inner sealing zone is the seal between the fluid contents of the piping system and the pressure chamber space. The outer sealing zone is the seal between the pressure-testing chamber and the ambient environment outside of the piping system.
[0035] Each pressure-testing chamber comprises an inlet, i.e. an opening from the pressure-testing chamber to the exterior of the fitting. In some embodiments, a valve is located at the end of the inlet on the outer surface of the sleeve. The pressure-testing chamber is created by the space between the inner and outer seals and between the inner surface of the sleeve and the outer surface of an inserted pipe. In some embodiments, the sleeve has a circumferential groove between the sealing zones. In an aspect of the present disclosure discussed below, the fitting comprises a valve, which is also the electrode for supplying electric current to one or more coils to enable electrofusion.
[0036] The pressure chamber can have the shape of a groove, carved out from the inner surface of the sleeve. The groove can have a variety of shapes. In some embodiments, the groove has a box-like shape. In other embodiments, the groove has a triangular shape. However, the shape should generally not have sharp corners because they create stress concentrations at the cornered potions of the cross-sections. Thus, a triangular groove looks more like a graphical representation of Gaussian distribution, i.e., with a rounded top of the triangle instead of a point. However, in such triangular shapes, a stress concentration would be focused on the edge of the fusion zone, thereby limiting the amount of pressure that can be applied and increasing the possibility of slow crack growth (SCG). In further embodiments, the groove has a round shape.
[0037] In some embodiments, the groove has a cross-section having one width near the inner surface of the fitting and a wider width further from the inner surface of the fitting.
[0038] In some embodiments, the pressure-testing chamber comprises a groove in the section of the pipe to be inserted in the fitting. In this embodiment, the groove on the pipe would align to an inlet on the fitting. When electrofused to the fitting, the pressure-testing chamber would be formed by the groove on the pipe, the inner surface of the fitting, and the inner and outer seals between the pipe and the fitting. An inlet through the fitting would allow for testing of the outer and inner seals via the pressure-testing chamber. In some embodiments, the pipe and fitting can both have grooves to form a pressure-testing chamber between the inner and outer sealing zones.
[0039] In some embodiments, the fitting also comprises one or more cold zones. A cold zone is a section of the fitting that does not melt. Typically, a cold zone is a section of the fitting that does not have a concentration of coil. In some embodiments, the fitting also comprises at least a first cold zone in between a first pair of sealing zones, at least a second cold zone in between a second pair of sealing zones, and at least one cold zone in between the first and second cold zones. The cold zone in between sealing zones helps to mitigate the effects of residual stress in pipe sections or misalignment resulting from poor insertion.
[0040] Each sealing zone comprises sealing means to form a seal with an inserted pipe. In some embodiments, at least one of the sealing zones comprises an electrofusion coil or an electrical heating coil. In some embodiments, the electrofusion coil section is arranged in or on the internal surface of the fitting encircling the sealing zone, and the fitting comprises contacts for supplying electric current to the first electrofusion coil. A seal is formed between the fitting and an inserted pipe by supplying electric current to the coil that produces heat in a sufficient and suitable amount to melt the plastic surface of the fitting in the sealing zone and the outside surface of the inserted pipe, thereby causing the melted plastic to weld and form a seal. As discussed further below, in some embodiments, the valve for the pressure-testing chamber is also the contact for supplying electric current to one or both electrofusion coil sections in each sealing zone.
[0041] In certain embodiments, a fitting comprises a sealing zone with different sealing means. In some embodiments, a sealing zone comprises an indent sized and shaped to hold an O-ring in the interior surface of the sleeve. In some embodiments, the fitting further comprises an O-ring. In some embodiments, the outer sealing zone is the O-ring sealing zone. When the O-ring sealing zone is the outer sealing zone and the inner sealing zone is an electrofusion sealing zone, then a person of ordinary skill in the art would understand that the joint is still an electrofusion joint because the inner seal, i.e., the seal proximal to the fluid contents of the piping system is an electrofusion seal. In some embodiments, the inner sealing zone is the O-ring sealing zone. In further embodiments, both sealing zones are O-ring sealing zones.
[0042] In another aspect, the present disclosure provides an improved design when at least one sealing zone comprises an O-ring sealing zone. Turning now to
[0043] A further advantageous feature of the fittings of this disclosure is the non-destructive nature of the testing of the integrity of the seals, through the arrangement of the pressure-testing chambers of the fittings of the invention. The pressure-testing chambers have inlets that are on the outside of the fitting and need no drilling or guiding of probes through the pipes. In certain embodiments, the inlets are configured with valves, or valves can be part of external equipment used for pressure-testing. In some embodiments, the sleeve portion is dimensioned to allow for high pressure in the pressure chamber, thereby allowing for testing with desired pressure. The fittings of this disclosure can be used on all sizes of polyethylene pipe used in piping systems.
Pressure-Testing Valve and Current Connector
[0044] In another aspect, this disclosure provides a valve for pressure-testing pipe joints connected by the pipe fittings of this disclosure. In one aspect of the disclosure, the valve connected to the pressure chamber and the connector for supplying electric current to the coils for electrofusion are the same component. In some embodiments, an electrode sits at the end of the coil in the electrofusion fitting. In some embodiments, a counterpart to that electrode sits in a corresponding location at the opposite end of the coupler. In some embodiments, the coils are double wound so that both ends of the coil are situated at the same end allowing for the nodes to be side by side.
[0045] In one aspect of the present disclosure, the pressure-testing valve is situated on the pipe fitting so that it is (i) located directly over the testing chamber; and (ii) located outside of the integrity of the piping system specifically. When located directly over the pressure-testing chamber, the pathways pressurized during the test do not weaken or compromise the structural integrity of the fitting. As a result of these two features, the joint can be tested during its service time and can be classified as a Non Destructive Test (NDT).
[0046] The present disclosure provides the main structural welding zones which are necessary for complying with any current regulations such as EN1555. These zones are required to seal the pipe. The outer seals are considered test seals, back up seals, or secondary containment seals.
[0047] Another aspect of the present disclosure provides an arrangement of the valve such that the electrofusion coil can be double wound or otherwise connected back to the valve location allowing for the valve to also serve as an electrode. In some embodiments, the electrode has a plastic shell around it to ensure against any shock damaging the electrode. In certain embodiments, that shell can also be conductive to allow a current to be induced across the coil by using the shell as the electrode. This design allows for the following advantages over the prior art: a.) forward and backward compatibility of existing PE systems and the joints of this disclosure; b.) a viable mating site for a monitoring device for use in a smart joint or Smart Water Network; and c.) with the location outside of the main welding zone and the ability of the valve system to be rated to substantial pressures, the joint can provide secondary containment if the outer seal is sufficiently robust.
[0048] Returning to
Monitoring Seal Integrity
[0049] Yet another aspect of this disclosure provides fittings, systems, and methods for monitoring the integrity of joints, detecting a leak or breach in the integrity of a joint, and/or relaying information about a leak or breach in the integrity of a joint. As shown in
[0060] One aspect of this disclosure is directed to fittings and methods for monitoring and detecting the above-described changes in states. The fittings described herein can further comprise a sensor fluidically connected to the inlet or pressure-testing chamber. In some embodiments, the sensor is selected or designed to monitor or detect one or more of the above-described states. In some embodiments, sensors can be designed and implemented to extract data for analysis and interpretation along the following exemplary organizational categories pertaining to seal failures: 1.) Cautionary, whereby the outer seal only has failed; 2.) Impending, whereby the inner seal only has failed; and 3.) Immediate, whereby both seals have failed.
[0061] In some embodiments, the sensor is in or proximal to the test site and the data gathered could be used to determine the state of the inner and outer seals. In some embodiments, the sensor is a temperature gauge. In some embodiments, the sensor is a thermocouple. For example, if a test chamber no longer holds pressure and a temperature sensor reads the test chamber as equal to the ambient environment temperature outside of the piping system rather than operating temperature of the fluid inside the pipe, this would indicate that the inner seal is intact and the outer seal is faulty.
[0062] There are many sensors that can be used in connection with the fittings of this disclosure. In some embodiments, the sensor is designed for passive water flow analysis. In certain embodiments, the sensor is an acoustic sensor or a vibration sensor. In other embodiments, the sensor is an air-gas ratio sensor, which can be used in gaseous pipelines. In some embodiments, the sensor is designed for volumetric airflow or fluid flow calculations. In certain embodiments, the sensor is a mass flow sensor.
[0063] In some embodiments, the sensor can be a specific gas sensor. For example, the specific gas sensor can be a sensor for O.sub.2, CO.sub.2, H.sub.2, CO, etc.
[0064] In some embodiments, the sensor is designed to detect changes in pressure in the pressure-testing chamber. In certain embodiments, the sensor is a pressure sensor.
[0065] In some embodiments, the sensor is a water sensor.
[0066] In certain embodiments, the sensor is designed for circuit manipulation based on the sate of the chamber. In some embodiments, the sensor is a chemical transistor or a chemical resistor.
[0067] In certain embodiments, the sensor is an ion sensor or a radiation sensor.
[0068] In other embodiments, the sensor is a galvanometer.
[0069] In some embodiments, the sensor is designed to determine pipe fluid flow or flow through pressure chamber. In certain embodiments, the sensor is a flow sensor or an mflow meter.
[0070] In some embodiments, the sensor is designed to determine damage caused by earthquake and other shock trauma leading to failure. In certain embodiments, the sensor is a strain gauge or piezoelectric sensor.
[0071] In some embodiments, the sensor is designed to determine temperature flow. In certain embodiments, the sensor is a heat flux sensor.
[0072] In some embodiments, the sensor is designed to gauge temperature using solid state methods. In certain embodiments, the sensor is a thermistor.
[0073] A further aspect of this disclosure is directed to fittings and methods for detecting a failure of a seal and collecting or storing data about the state of a seal. In some embodiments, the data is collected or stored on a device that can store data or transmit data over hard wired or wireless networks. In a piping system touted to last 100+ years, powering the sensing equipment is a challenge because the sheer volume of joints makes it impractical to use conventional methods. Furthermore, some smart water networks regulations require battery lifetimes of at least 15 years. This disclosure provides a solution that creates a power supply that can lie dormant and inactive until a failure presents itself, after which the power supply lasts a period of time dependent on design parameters. Furthermore, in circumstances where the power supply has expired, this disclosure also provides an embodiment where the data tracker component registers a state change noting the activation of the power unit and, with that activation, the leak associated with it. This change in state on the data can be permanent.
[0074] In one aspect, a fitting of this disclosure comprises a dormant battery and a data tracker. The dormant battery comprises a dry or a paste electrolyte disposed in a portion of the annular pressure-testing chamber, an anode, a cathode, and circuitry electronically connecting the anode, cathode, and the data tracker. Examples of electrolytes that can be used include soluble acids, soluble bases, or salts that dissociate in an aqueous solution. An electrolyte can be selected based on the contents of the piping system. Other considerations such as stability over time, availability, and cost are also considered when selecting an electrolyte. In some embodiments, the electrolyte is silver nitrate. In some embodiments, the electrolyte is a soluble acid. In some embodiments, the electrolyte is nitric acid. In some embodiments, the electrolyte is a salt. In some embodiments, the electrolyte is sodium chloride. In some embodiments, the electrolyte is an alkaline electrolyte. In certain embodiments, the electrolyte is selected from the group consisting of potassium hydroxide and sodium hydroxide. In some embodiments, the anode or cathode is copper. In some embodiments, the anode is zinc. In some embodiments, the anode is iron. In some embodiments, the cathode is manganese (IV) oxide. In some embodiments, the cathode is silver. In some embodiments, the cathode is nickel oxide. A person of ordinary skill in the art would understand that there are many combinations of anode, cathode, and electrolyte that could work in the described dormant batter.
[0075] In some embodiments, the dormant battery is a lithium-air battery without the aqueous solution.
[0076] In some embodiments, the dormant battery also comprises a stabilizer to ensure the effectiveness of the electrolyte over time. In some embodiments, the stabilizer is an antioxidant. An antioxidant can be selected to aid in the preservation of the dormant life of the battery. In some embodiments, the stabilizer is butylated hydroxytoluene (BHT). A person of ordinary skill in the art would understand that other stabilizers can also be used.
[0077] In some embodiments, the data tracker is an RFID chip. In some embodiments, the data tracker is a semiconductor. In some embodiments, the data tracker is a light-based memory chip. RFID chip and antenna assemblies relay data using near field communication. The distance over which data can be transmitted is dependent on whether it is a passive RFID (no power supplied) or an active RFID (power supplied). In some embodiments, an RFID affixed to every annular test ring is passive at time of install of the fitting. The RFID may contain and collect data including but not limited to temperature, date, time, name of installer, weld and cool time, geolocation, any data collected by a connected sensor, and other specs relative to the fitting's installation. In some embodiments, at least one other data point is included: a binary state of failure. In some embodiments, this data point is default set to indicate no leak has occurred. In some embodiments, the RFID chip and antenna assembly is connected to the anode and cathode, which can be differential metals. The anode and cathode enter a chamber containing the dry electrolyte and stabilizer mix. Referring back to
[0078] In the event of a failure that water enters into an electrolytic mix and effects a state change to the RFID, it can be assumed that the inner seal has failed. However, the outer seal may or may not be intact. In some embodiments, the sensor can relay the relevant seal data, based on the detection of the relevant change in state or states described above, to the data tracker which can then inform a control station or worker in the field reading the signal that there was an impending leak or an immediate leak. Depending on the piping system, one or more sensors can be designed or implemented to detect one or more of the states described herein.
[0079] Sensor data recorded to any chip or relayed to any monitoring station need not be dependent on failure to power it. In some embodiments, the data tracker can be externally powered. Key points in the system may receive static power to gather data for analytics to be performed in order to create a smart water network not dependent on failure. Static power can be provided based on conditions related to the piping system. In some embodiments, piping systems contained within a specific industrial area or station (e.g., a power plant, a manufacturing facility, a ship, an industrial building, etc.) could have all vital joints proximal to some power and monitoring connections. Embodiments with external static power are not limited to specific areas or station and can receive static power in metro areas where such supplying power is accessible and feasible.
[0080] This disclosure also provides a method for making the dormant power source. After the pressure test is conducted, and the integrity of the inner and outer seals confirmed, a vacuum can be imposed on the pressure-testing chamber, followed by the introduction of the electrolyte into the pressure-testing chamber after the vacuum is released. In some embodiments, a stabilizer is also introduced to the pressure-testing chamber with the electrolyte. The anode, cathode, and circuitry for connecting to a data tracker can be introduced to the fitting before or after the electrolyte is introduced into the pressure-testing chamber. At this stage, the integrity of the seals has been confirmed and a dormant battery has been created in the pressure-testing chamber.
[0081] In some embodiments, the dormant battery (comprising dry electrolyte, an anode, and a cathode) is a component separate from the fitting. In some embodiments, the inlet valve used for conducting a pressure test in the pressure-testing chamber can be removed from the fitting. In such embodiments, the inlet valve can be replaced with a dormant battery comprising a dry electrolyte, an anode, a cathode, and circuitry for connecting the anode, cathode, and data tracker(s). In such embodiments, the dormant battery need only be positioned so that an aqueous liquid that breaches an inner or outer seal can contact the electrolyte. In some embodiments, the dormant battery component further comprises a sensor. In some embodiments, the valve and dormant battery are the same component. In some embodiments, the dry electrolyte is contained in a portion of the annular testing chamber and the dormant battery component comprises an anode, a cathode, one or more data trackers, and circuitry necessary to connect the anode and cathode to the one or more data trackers. In some embodiments, the electrolyte is contained on a sponge or other absorbent material.
Personal Flotation Devices
[0082] Another aspect of this disclosure is directed to personal flotation devices (“PFDs”). PFDs are frequently used in emergencies involving aircraft or watercraft. PFDs can be inflatable or comprise buoyant material or a combination of inflatable and buoyant material. Generally, PFDs contain a small battery and circuitry for powering a light or a beacon for signaling a person's location in the event of an emergency. Typically, the battery does not become fully connected to the circuit until it has become sufficiently wet or submerged in water. However, the battery loses its charge over time. As a result, PFDs comprising these batteries must be replaced periodically—even if the PFDs haven't been used—in order to make sure the light or beacon can be powered in the event of an emergency.
[0083] In one aspect, this disclosure is directed to a PFD comprising a dormant battery. In some embodiments, the dormant battery comprises a dry electrolyte, an anode, a cathode, and circuitry for connection to a device requiring power. In some embodiments, the dormant battery also comprises a stabilizer to maintain the electrolytes effectiveness. The dormant battery can be contained in a section of the PFD. In some embodiments, the section is a sealed pocket that can be permeated by water. In some embodiments, the dormant battery is a separate, self-contained component that can be attached to a PFD. In some embodiments, the electrolyte is silver nitrate. In some embodiments, the anode is zinc. In some embodiments, the cathode is copper. A person of ordinary skill in the art would understand that numerous combinations of electrolyte, cathode, and anode can be made. Such combinations are intended to be within the scope of this disclosure. Furthermore, the dry electrolytes, anodes, cathodes, and stabilizers described above for the dormant battery in the pipe fitting are also applicable to the PFD dormant battery.
[0084] When the PFD of this disclosure comes in contact with a sufficient amount of water, such that the dormant battery is submerged or sufficient water enters the dormant battery, the water creates an electrolytic solution and the battery becomes active. Current is allowed to flow and power a device. In some embodiments, the device is a light. In some embodiments, the device is a beacon transmitting information, e.g., an SOS message or location information.
[0085] A major advantage that the PFD comprising a dormant battery over the prior art is increased shelf life. Batteries in prior art PFDs lose their charge over time. The dormant batteries of this disclosure maintain the ability to be activated for a longer time. The increased shelf life of the PFDs of this disclosure cuts down on the replacement costs.