Moisture detecting air cap indicator for expansion tank failure.

(54) Title: AIR COVER INDICATOR FOR THE DETECTION OF HUMIDITY FOR FAILURE OF THE EXPANSION TANK.

(54) Title: MOISTURE DETECTING AIR CAP INDICATOR FOR EXPANSION ΤΑΝΚ FAILURE.

(57) Summary

An expansion tank is described having an internal cavity separated by a flexible diaphragm to form an upper pressurized gas part and a lower fluid part, and an indicator positioned in an upper part of the expansion tank in communication with the contents of the expansion tank. upper pressurized gas part. The indicator is configured such that it shows a first color if the operating conditions are normal in the pressurized gas part and a second color if the amount of moisture detected in the pressurized gas part is greater than or equal to a predetermined amount . Additionally, a method for detecting whether there is an excessive amount of moisture in a pressurized gas part of an expansion tank is described, allowing the pressurized gas from the pressurized gas part to come into contact with the indicator and observe the color. displayed by the indicator. As a result, the tank can be simply visually inspected to determine if there is a potential failure in the tank.

(57) Abstract

Disclosed is an expansion tank having an internal cavity separated by a flexible diaphragm to form an upper pressurized gas portion and a lower pressurized fluid portion, and an indicator positioned at an upper part of the expansion tank in communication with the contents of the upper pressurized gas portion. The indicator is configured so as to display a first color if the operating conditions are normal in the pressurized gas portion, and a second color if the amount of moisture detected in the pressurized gas portion greater than or equal to a predetermined amount. Further disclosed is a method for detecting whether there is an excessive amount of moisture in a pressurized gas portion of an expansion tank by allowing pressurized gas from the pressurized gas portion to come into contact with the indicator, and viewing the color displayed by the indicator. As such, the tank can be simply visually inspected to determine whether there is a potential failure in the tank.

AIR COVER INDICATOR FOR HUMIDITY DETECTION FOR EXPANSION TANK FAILURE

Cross reference to related requests

The present application claims the benefit and priority of US Patent Application No. 14 / 291,894, filed May 30, 2014. The entire contents of the above application are incorporated herein by reference in their entirety.

Field of invention

The present invention relates generally to expansion tanks, and more particularly to diaphragm expansion tanks that have an indicator to alert a user if moisture is found on the gas side of the expansion tank.

Background

Expansion tanks are commonly used in heating, cooling, and air conditioning systems to prevent an unacceptable rise in system pressures during heating, usually by absorbing the expanding fluid and limiting the pressure within the system. Expansion tank designs include open tanks, closed compression tanks, and diaphragm tanks.

In a diaphragm expansion tank, a diaphragm or bladder is used to separate the air from the water inside the tank.

In particular, one side of the tank connects to the piping of a heating system (or cooling / air conditioning system) and thus contains the water, while the other side contains air under pressure. Typically, a Shrader valve is provided on the air side of the tank to check the pressure and add the air, allowing the tank pressure to be adjusted as needed.

An air / gas charging pressure on one side keeps the diaphragm at a distance away from the side wall of the tank on the gas side. When the tank is installed in a water system, the pressure of the water system pushes again against the diaphragm, compressing the gas.

When the system cools down and the water in the tank is at its minimum level, the tank pressure is at an initial / precharge pressure. As the temperature in the system increases, the water expands to compress the gas chamber through the diaphragm, causing an increase in the pressure of the gas and water system.

However, the diaphragm has a limited life. If the diaphragm eventually reaches the lowest point on the tank wall, the tank loses efficiency in the function for which it was designed. Various failure modes for expansion tanks include incorrect precharge pressure (e.g. low air precharge), excessive system pressure, diaphragm failure resulting in air charge leakage, and installation of a wrong size tank (for example undersized tank causing diaphragm to do excessive work), all of this can lead to rapid cycling and ultimately failure. In such failure modes, the diaphragm can develop a small hole, an abrasion, a cut, or the like that allows water to enter the gas side of the tank. Over time, the gas will be absorbed into the water system and the gas charge will decrease to zero. At this point, the tank is considered ineffective. This can eventually lead to a failure of other equipment in the system or failure of the tank itself, resulting in water leaking into the space surrounding the tank.

In order to determine if there are any problems with the operation of the expansion tank or if the expansion tank has suffered a failure, an owner will often need the services of a plumber to remove the tank from the system and evaluate it. This is time consuming and expensive. Therefore, it would be beneficial to provide a mechanism that makes it easier for a homeowner or plumber to determine if an expansion tank is in trouble or has suffered a failure, thus allowing more proactive equipment maintenance. Such a mechanism can also beneficially alert a user to initial problems in the tank, which can potentially be addressed to avoid tank failure.

Compendium

The present invention provides an expansion tank that includes a housing having an upper end wall, a side wall, and a lower end wall that together define a cavity. A flexible diaphragm extends into the cavity, in order to separate the cavity into an upper part, which is sealed to contain a pressurized gas and a lower part, which is sealed to contain a pressurized fluid. An indicator is positioned on the top wall of the housing, so as to visually alert the user if moisture is found on the pressurized gas side of the expansion tank.

According to one embodiment, the indicator is in the form of an air cap indicator that is positioned on an upper end wall of the tank and in communication with the pressurized gas side of the tank.

According to various embodiments, the indicator comprises an insert displaying a first color. When in contact with a predetermined level of humidity or higher the indicator shows a second color. Preferably, the predetermined level of humidity is a minimum amount of humidity and, in some embodiments, the predetermined level of humidity is such that drops of water are formed and there is even a volume of water. In still further embodiments, the predetermined moisture level is a level at which the material (eg, iron) that forms the pressurized gas side of the tank corrodes and oxidizes.

According to various embodiments, the indicator further comprises a cap in an upper part, the insert is arranged, at least partially within the cap, and extends laterally laterally from the cap towards the upper end wall of the housing, where a gas tight seal and fluid tight seal are formed between the indicator and the upper end wall of the housing. According to various embodiments, at least a part of the cap is made of a transparent material through which the insert is viewed. At least a part of the cap can be made from an optically magnifying material so that the insert can be seen and is magnified through it.

According to one embodiment, the cap is provided with a first color and when the pressurized gas side of the tank comes into contact with the predetermined level of humidity or higher, the material that forms the pressurized gas side corrodes and oxidizes. This corrosion and oxidation will then deposit a residue on the surface of the lid. Alternatively, the cap is provided with a first color and at least a portion of the indicator is manufactured from a material that is hydrochromic, such that the first color will change to the second color when it comes in contact with the predetermined level of humidity or higher. Preferably, this first color is a light color that will contrast with the second color and with the oxide, which typically has a red-orange-brown color. According to a preferred embodiment, the cap has a bright white color, which provides a pronounced contrast to the deposited oxide. The bright white, or other color, of the cap can be provided either by the material itself that forms a cap (for example, by using a white plastic material that forms on the cap) or by painting the cap with the desired bright white or other color.

According to various embodiments, at least a part of the insert is coated with a hydrochromic ink. Hydrochromic ink shows the first color. Hydrochromic ink lightens when it comes in contact with the predetermined level of humidity or higher and therefore the second color is displayed.

According to various embodiments, the insert has the first color. When there is a predetermined amount of moisture or greater, oxide deposits form in the first color to indicate a second color. In a further embodiment, drops of water or even a volume of water can be seen through the transparent part of the lid where the insert is seen.

According to various embodiments, the indicia is arranged to house a valve in the upper end wall of the housing, the valve being in communication with the pressurized gas at the top of the cavity.

In another embodiment, a method is provided for indicating a failure in an expansion tank comprising a flexible diaphragm, where the flexible diaphragm divides the tank into a pressurized gas side and a pressurized fluid side. An indicator is positioned on an upper end wall of the expansion tank and in fluid communication with the pressurized gas side, for example, by a valve. The indicator includes a cap having a cap insert that is disposed therein. In particular, the lid has a dome-shaped part (lid dome), at least a part of which is transparent so that the user can see the contents therein. The cap insert is designed to display a first color when the pressurized gas side of the tank is in its normal operating condition and to display a second color when exposed to a predetermined level of humidity or higher. In order to evaluate the expansion tank, the valve is activated to allow pressurized gas from the pressurized gas side of the tank to enter the lid dome and come into contact with the lid insert. If the pressurized gas side of the tank has been exposed to or contains a detectable level of moisture, then the cap displays the second color to indicate problems with or failure of the expansion tank. If the pressurized gas side of the tank was not exposed to or does not contain a detectable moisture level, then the layer insert will display the first color to indicate that the expansion tank is operating properly. Preferably, the predetermined level of humidity is a minimum amount of humidity, in some embodiments the predetermined level of humidity, such that drops of water are formed and there is even a volume of water and, in still other embodiments, the predetermined level Moisture is a level at which the material (for example, steel) that forms the pressurized gas side of the tank will corrode and rust.

Other objects and advantages of the invention will be set forth in part from the description that follows and in part will be apparent from the description or may be learned by practice of the invention. The objects and advantages of the invention can be carried out and obtained by the noted elements and combinations described herein include those appended claims. It should be understood that both the foregoing general description and the following detailed description are provided by way of example and explanation only and do not limit the invention as claimed. The attached figures, which are incorporated into and form a part of this specification, illustrate various embodiments of the invention and, together with the description, serve to explain the principles of the invention.

Brief description of the figures

Figure 1 is a cross-sectional view of an example of a previously pressurized expansion tank with an indicator;

Figure 2 is a cross-sectional view of the example expansion tank of Figure 1 partially filled with a fluid;

Figure 3 is a cross-sectional view of the example expansion tank of Figure 1 filled with a fluid;

Figure 4 is a cross-sectional view of the example expansion tank of Figure 1 in a failure mode with a gas section under pressurization.

Figure 5 is an enlarged sectional view of a portion of the example expansion tank of Figure 1;

Figure 6A is an enlarged cross-sectional view of the example indicator shown in Figure 1 in the normal operating position; and

Figure 6B is an enlarged cross-sectional view of the indicator example shown in Figure 6 in the alert / fail position.

It should be understood that the accompanying drawings are not necessarily to scale, which presents a somewhat simplified representation of various preferred elements illustrative of the basic principles of the invention. Specific design features of the present invention as described herein, including, for example, specific dimensions, orientations, locations, and shapes will be determined in part by the particular intended application and medium of use.

In the figures, reference numbers refer to equal or equivalent parts of the present invention throughout various figures of the drawings.

Definitions

To facilitate an un derstanding of the present invention, a number of terms are defined below.

As used herein, the singular forms a, an, and the, la include plural forms, unless the context clearly indicates otherwise. Thus, for example, a reference to a sensor includes a reference to more than one sensor.

Unless otherwise specified or obvious, as used herein, the term or is understood is comprehensive.

The term "including" is used herein with the meaning, and is used interchangeably with, the phrase "including," but not limited to.

As used herein, the terms "comprising, comprising, containing, having and the like" may have the meanings assigned to them in United States patent law and may mean "includes", "including" and the like; consisting essentially of or consisting essentially of, in the same way, have the designated meaning in United States patent law and the term is open, allowing the presence of more than is expressed, as long as the basic or new characteristics of what is expressed do not change due to the presence of more than what is expressed, but exclude modalities of the prior technique.

As used herein, an excessive amount of moisture means any moisture present on the pressurized gas side of the tank as a result of a compromised diaphragm.

As used herein, a predetermined level of humidity or greater is one that causes the cap to change from one color to another color, such as causing a hydrochromic ink to change color or causing a material (for example, iron ) that forms the pressurized gas side of the tank corroding and oxidizing, or allowing water droplets or a volume of water to be present. Said predetermined level can include, in some embodiments, a minimal amount of moisture or, in other embodiments, any amount of moisture, such that drops of water are formed and there is even a volume of water.

Unless otherwise specified or obvious, as used herein, the term "around" is understood to fall within a normal tolerance range in the art, eg, within 2 standard deviations of the average. Around can be understood comprised of 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.5%, 0.1%, 0.05% or 0.01% of the set value. Unless evident from the context, the numerical values ​​provided herein are modified by the term around.

The ranges provided herein are abbreviated for all values ​​within the range. For example, an interval from 1 to 50 is understood to include any number, combination of numbers, or subinterval of the group consisting of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43,

44, 45, 46, 47, 48, 49, or 50.

Any devices, components, apparatus, or methods provided herein may be combined with other devices, components, apparatus, and methods provided herein.

Detailed description

Improper well / expansion tank installations, as well as improper gas precharge and gas leak failures, can lead to eventual tank failures that can cause water to leak out of the tank. The undersized tank also results in more stress on the tank and can result in premature tank failure. The present invention provides an indicator for an expansion tank that can alert a user to a problem with the system, before a tank failure or leak occurs and / or at any time after a tank failure or leak occurs. leakage. In particular, the present invention provides an indicator that displays a first color when the tank is operating under normal operating conditions (i.e. where a moisture level is not found or an undetectable level of moisture is found on the gas side of the tank. tank), and showing a second color when problems were detected with the tank (that is, where there is any moisture or a detectable level of moisture on the gas side of the tank). This provides a visual aid in indicating tank problems and can be used to indicate if tank maintenance or replacement is required.

Referring now to Figures 1-4, an example pre-pressurized expansion 10 is shown. It is noted that the general characteristics of the expansion tank 10 may be in accordance with known expansion tanks and the example expansion tank 10 shown in the figures is an example of these. The characteristics of the expansion tank 10 depicted in the figures are similar to those shown in US Patent No. 5,386,925, issued February 7, 1995 entitled Expansion Tank and US Patent No. 7,032,628. issued April 25, 2006 and titled Mobile Prepressurized Diaphragm Type Fluid Storage Tank, which are incorporated herein by reference.

In the example shown herein, tank 10 has a housing 11, formed by an upper housing 12 and a lower housing 13, defining an internal cavity 14. A deformable diaphragm 16 and a liner 18 are positioned within the cavity 14 and are removably attached to the lower housing 13, for example, by a retaining ring 20 or the like. An indicator 30 is positioned in an upper portion of the upper housing 12 as described in more detail below.

The upper housing 12 has a generally cylindrical side wall 22 and an end wall 24. The upper housing 12 can be any size depending on the desired total volume of the tank 10 and can have the same general design as the lower housing 13. A conventional valve 50, such as a Schrader valve or the like, is preferably provided in the end wall 24 of the upper housing 12 to allow the addition of air (gas) to / from the cavity 14 to pressurize the tank 10.

The lower housing 13 also has a generally cylindrical side wall 26 and an end wall 28. The lower housing 13 may also be of any size depending on the desired total volume of the tank 10. A fit 32 is provided in the end wall 28 of the housing. bottom 13 to allow water to flow in and out of tank 10. As best seen in Figure 5, side wall 26 may have a concave groove 34 formed around its circumference, which may mesh with grooves formed in diaphragm 16, liner 18, and retaining ring 20, as described. later. Side wall 26 may further have an insert portion 36 (best shown in Figure 5) formed at one end of side wall 26, which creates an overlapping joint with side wall 22 of upper housing 12 when tank 10 is assembled. . Once assembled, the upper housing 12 can be welded or otherwise secured to the lower housing 13.

Upper and lower housings 12, 13 and retaining ring 20 can be manufactured from any suitable material capable of tolerating the desired pressure and compatible with the fluids to be stored or dispensed. High-strength structural steel is a conventional material that has been used to make the upper and lower housings 12, 13 and retaining ring 20 and allows the upper and lower housings 12, 13 to be joined by a welding process. However, a mechanical joint can also be used to join the upper and lower housings 12, 13 which can be formed from any material, as long as it provides a structural hermetic seal.

As shown in the figures, retaining ring 20 is curved with a concave outer portion and a convex inner portion, corresponding to and engaging with groove 34 in side wall 26, groove 17 in diaphragm 16, and groove 19 in liner 18, as described in more detail below, to anchor diaphragm 16 and liner 18 in place and provide a gas and water tight seal.

Diaphragm 16 is flexible and is preferably manufactured from an elastomer, such as butyl rubber, and is disposed within lower housing 13. As shown in Figure 5, diaphragm 16 has a protruding slot inward 17 adjacent its end and positioned such that its end is adjacent to the end of liner 18. As a result, slot 17 corresponds to and engages with slot 34 in housing 13 and retaining ring 20 to mechanically lock or secure diaphragm 16 to lower housing 13. According to various embodiments, diaphragm 16 is preferably molded to fit the inner shape of the lower housing 13. Therefore, the diaphragm 16 is compressed between the retaining ring 20 and the side wall 26 of the lower housing 13, which forms an air and fluid tight seal.

The liner 18 is preferably manufactured from an impermeable material, such as polypropylene, and is arranged to cover the interior surface of the inner housing 13. As shown, the liner 18 is positioned between the lower housing 13 and the diaphragm 16. Liner 18 preferably also has an inwardly protruding slot 19 adjacent its end and is positioned such that its end is adjacent to the end of diaphragm 16. As a result, slot 19 corresponds to and engages with slot 34 of housing 13 and retaining ring 20 to mechanically lock or secure liner 18 to lower housing 13. Therefore, liner 18 is compressed between the ring. retainer 20 and the side wall 26 of the lower housing 13, which forms an air and fluid tight seal.

The part of the cavity 14 arranged between the liner 18 and the diaphragm 16 forms a part that receives water from the cavity 14. Therefore, the water is contained between the liner 18 and the diaphragm 16 such that the entire The inner surface of the upper and lower housings 12, 13 are protected from water. As a result, corrosion of the tank 10 can be avoided. This beneficially allows the tank 10 to be constructed from any material, regardless of the effect of water on that material. As shown in Figures 1-4, liner 18 also has an opening that aligns with trim 32 and provides a liquid tight seal with trim 32 to prevent water in tank 10 from flowing between liner 18 and trim 32.

As clearly shown in Figures 1-4, an indicator 30 is provided on the end wall 24 of upper housing 12 of tank 10. Indicator 30 is in communication with the contents of cavity 14, particularly, the contents of the cavity 14 positioned on the diaphragm 16. In other words, the indicator 30 is in communication with the pressurized gas portion, which is located between the upper end wall 24 and the diaphragm 16.

According to an exemplary embodiment as shown in the figures, the gauge 30 is in communication with the valve 50 in such a way as to allow the contents of the tank to come into contact with the gauge 30 through the valve 50. For example, As shown in the figures, the indicator 30 can be configured to cover or enclose a portion of the valve 50 on the outer surface of the tank 10. Preferably, the indicator encloses valve 50 on the outer surface of tank 10 such that operation of valve 50 in removing the contents (pressurized gas) from tank 10 positioned on diaphragm 16 results in the entry of pressurized gas into indicator 30 and that it is contained in it.

According to one embodiment, the indicator 30 is installed in connection with the tank 10, preferably in connection with the valve 50, such that an air tight seal is formed between the indicator 30 and the tank 10. As a result, an air tight seal is formed. prevents leakage of gas and liquids into gauge 30 (ie, from outside atmosphere) and out of gauge 30 (ie, into external atmosphere). For example, gauge 30 may include one or more seals to ensure an air tight seal between gauge 30 and tank 10 so that the contents of the tank will not leak through gauge 30 over time.

According to various embodiments, the indicator 30 can be configured to display a particular color when the amount of moisture on the pressurized gas side of tank 10 is within acceptable limits and to display a different color when the amount of humidity is above acceptable limits. For example, indicator 30 may display a color that will stand out from other nearby components of tank 10 (eg, red, orange, or the like) when the amount of moisture on the pressurized gas side of tank 10 is above acceptable limits. . On the other hand, when the amount of moisture on the pressurized gas side of the tank 10 is within acceptable limits, then the indicator 30 will display a different color. For example, the different color can be, for example, any color similar to the nearby components of the tank 10 to mix (for example, black, gray, silver, white, etc.). Thus, the indicator 30 provides a user with a simple visual mechanism by which it can be determined whether or not there are operational problems in the tank 10. Such a simple visual mechanism can alert a user to initial problems present in tank 10 that can potentially be addressed through routine maintenance, thus potentially avoiding further failure of tank 10 that may result in a reduction system performance or subsequent failure of system components. Additionally, the visual mechanism can alert a user to tank failure, thus allowing a user to replace a failed tank in a more timely manner.

Gauge 30 may have any configuration that will cover or enclose portion of tank 10 (for example, valve 50 on the outside of tank 10) and which will allow tank contents expelled from valve 50 to enter gauge 30 and be contained. in this. For example, the indicator 30 may have a general dome-like shape (as shown in Figures 6A-B), a box-like shape, a cylindrical shape, a cone-like shape, and so on.

As shown in the example embodiments of Figures 6A-B, the indicator 30 includes a top cap 40, side walls 46 extending from the cap 40 and engaging the exterior surface of the tank 10, and the cap 42 is disposed, at least partially, within cap 40. The lid 40 may have a rounded, dome-like, general structure as shown in the figures or it may have any other configuration that allows it to contain at least a portion of the lid insert 42 therein.

At least a part of the indicator 30 is made of a transparent material through which a user can view the contents of the indicator 30. In particular, the indicator 30 is made of a transparent material in at least one part that allows a user clearly observe the cap insert 42. For example, the cap 40 as a whole may be transparent, as shown in Figure

6B such that it allows an easy and unobstructed view of the cap insert 42 through the cap. As shown in Figure 6B, the remainder of the indicator 30, such as the side walls 46, can be made from a non-transparent material or can be made from a transparent material, if so desired.

In accordance with embodiments of the present invention, at least a portion of the lid insert 42 is manufactured such that it displays a second color when exposed to predetermined levels of humidity or displays water if a volume of water is encountered, and displays a first color when under normal conditions. In general, there should not be any moisture present within the pressurized gas side of tank 10 and therefore the moisture level or only the minimum moisture level is acceptable. In some embodiments, an acceptable level of humidity is the level below that detectable by cap insert 42 in order to cause the cap insert 42 to change color.

For example, at least a portion of the cap insert 42 can be fabricated such that it displays a first color when exposed to no moisture or less than detectable levels of moisture and displays a second color when exposed to any level. humidity greater than around zero (for example, detectable humidity levels). As a result, a user can simply observe the lid insert 42 through the lid 40 to determine the color of the lid insert 42 and, as a result, can alert him to the operation of the tank 10.

According to one embodiment, the cap 40 is manufactured from a material that optically enhances the contents of the cap 40 as viewed through it. As a result, the layer insert 42 can be more easily observed and the color viewed to determine whether the tank 10 is satisfactory or defective.

In accordance with an exemplary embodiment, the lid insert 42 has a top portion 44, which may have a dome-like shape as shown in Figure 6B, projecting into the lid portion 40 of the insert. 30. Top 44 is configured and disposed within cap 40 to be clearly visible through cap 40.

According to a preferred embodiment, at least a portion of the lid insert 42 (for example, the top 44 that is visible through the lid 40) is formed to have a first color which is the color that indicates that the tank works correctly. When the pressurized gas side of tank 10 is exposed to moisture, the material that forms the pressurized gas side of tank 10 will corrode and oxidize. This corrosion and oxidation present in the indoor environment will rapidly deposit oxide residue on the surface of the cap insert 42. As a result, the first color of the cap insert 42 is preferably one that contrasts with the color of the deposited oxide, which has a color typically red-orange-brown. In accordance with a preferred embodiment, the cap insert 42 has a light color, such as a bright white color, which provides a pronounced contrast to the deposited oxide. The bright white or other color of the cap insert 42 can be provided by any conventional method. In some embodiments, the material that forms the cap insert 42 (or a portion of the cap insert 42, such as the top 44, visible through the cap 40) may itself be that of the first desired color. . For example, the cap insert 42 or part thereof may be molded or otherwise formed from a white or other colored plastic material into the desired shape. Alternatively, the cap insert 42 can be formed from any material of any color and can be further colored as desired.

According to other embodiments, at least a portion of the indicator 30 that is in communication with the cap insert 42 is formed from a material that will corrode and oxidize when exposed to moisture. This makes it possible to form the tank 10, which includes the pressurized gas side, from a material that is resistant to corrosion. In such modes, tank 10 is evaluated to allow pressurized gas from the pressurized gas side of the tank to enter gauge 30. If moisture is found in the pressurized gas, it will corrode and oxidize the portion of gauge 30. This corrosion and oxidation is present. In the interior environment of the indicator 30 it will rapidly deposit oxide residue on the surface of the cap insert 42. A further embodiment is that water droplets or a volume of water will accumulate between cap insert 42 and cap 40 where it will be visible on top 44.

In accordance with some embodiments, at least a portion of cap insert 42 visible through cap 40 (eg, top 44) is coated with a hydrochromic ink. Hydrochromic inks are widely known and will not be described in detail here. Instead, such known hydrochromic inks can be suitably used.

For example, in some embodiments, the hydrochromic ink may display a first color when in normal operating condition and may display a second color when in contact with a predetermined amount of moisture or greater (for example, a detectable level humidity, such as greater than minimum humidity levels or greater than zero humidity). As a result, the top portion 44 (or other desired portion of the cap insert 42) can simply be coated with the hydrochromic ink. Any contact of the hydrochromic ink covered portion with the predetermined amount of moisture or greater will result in the ink showing the second color, indicating tank problems. The second color is preferably any color that stands out to a user, for example red, orange, etc. The second color can be any different color than the first color (for example, white, silver, gray, etc.).

In another embodiment, the hydrochromic ink can display the first color when it is in contact with less than the predetermined amount of moisture and can become transparent when it comes in contact with the predetermined amount of moisture or more. As a result, the top 44 (or other desired portion of the lid insert 42) can be coated with the second color that alerts a user when there is a problem with the tank (eg, excessive moisture / any amount of moisture). The second color can then be coated with the hydrochromic ink. Any contact of the hydrochromic ink covered portion with the predetermined amount of moisture or greater will result in the ink becoming transparent to thereby reveal the second color.

According to an exemplary embodiment, the top 44 of the cap insert 42 is provided with a white band (or any color other than the second color) of hydrochromic ink radially around the insert 42. When the white band remains white (or a different color than the second color) then the tank is considered satisfactory (ie, no moisture / acceptable moisture levels present on the pressurized gas side of tank 10). If water leaks into the pressurized gas side of tank 10, the water will reach cap 40 of gauge 30 through valve 50 along with pressurized gas (or other means through which the pressurized gas leaves the tank 10). The pressurized gas containing the water enters the cap 40 and comes into contact with the hydrochromic ink in the cap insert 42. If water is found in the pressurized gas, then the water will make the hydrochromic ink invisible, revealing the second color (eg red) underneath (or change the color of the hydrochromic ink to the second color). The color change (for example, from white to red) will indicate that tank 10 has water on the pressurized gas side of diaphragm 18 and has failed.

According to a preferred embodiment, the cap insert 42 is painted a second color and then coated with a hydrochromic ink of a first color which (1) turns transparent to reveal the second color underneath when it comes into contact with the quantity humidity or higher and returns to the first color after the humidity has dried, or (2) changes to the second color when it comes in contact with the predetermined amount of humidity or higher, and returns to the first color once the moisture has dried. As a result, the indicator 30 is reusable and therefore does not need to be replaced once it came into contact with moisture and changed color.

As shown in Figure 6A, the indicator 30 can be designed to have two molded plastic gaskets that act as a primary seal 47 and a secondary seal 48. The various parts of indicator 30 can be formed by any method, such as molding and the like. Preferably, the cap 40 is molded to form a transparent material and the cap insert 42 is cast in a natural or white color and then painted with the second color and the first color. The various components can be assembled and joined by using sonic welding or similar methods which will ensure that a tight seal is formed.

As shown in Figure 6A, the primary seal 47 may be disposed at an upper location of the indicator 30 between the cap insert 42 and the valve 50 such that a seal is formed between the end of the valve 50 and the part. 44 of indicator 30. Secondary seal 48 may be disposed in a lower portion of gauge 30 between valve 50 and the upper surface of tank 10 to provide a middle seal that will prevent passage of gas and liquids between gauge 30 and the exterior of gauge 30.

In order to evaluate tank 10, valve 50 is activated to allow pressurized gas within tank 10 to enter gauge 30, particularly, enter cap 40 and come into contact with cap insert 42. Yes the pressurized gas is within an acceptable level, then the cap insert 42 remains unchanged in color. On the other hand, if moisture is found in the pressurized gas above an acceptable level, then the cap insert 42 changes color.

According to an exemplary embodiment, the cap insert 42 or part thereof is a first color and at least a part of the pressurized gas side of tank 10 is manufactured from a material that corrodes and oxidizes when it enters. contact with moisture. According to another exemplary embodiment, the cap insert 42 or part thereof has a second color and at least a portion of the indicator 30 that is in communication with the cap insert 42 is formed from a material that will corrode. and will rust when exposed to moisture. In these modes, if moisture is found on the pressurized gas side of the tank

10, the material that forms the pressurized gas side of tank 10 or lid insert 42 will corrode and oxidize when exposed to pressurized gas containing moisture. This corrosion and oxidation present in the indoor environment will rapidly deposit oxide residue on the surface of the lid insert 42. This deposited oxide changes the color of the lid insert 42, thus indicating that there is an excessive amount of moisture. on the pressurized gas side of the tank 10. If the moisture in the pressurized gas is at an acceptable level, then corrosion and oxidation do not occur and the color does not change from the first color, indicating that the amount of moisture on the pressurized gas side of tank 10 is acceptable.

According to another exemplary embodiment, the cap insert 42 is painted with a second color (eg, red) and then colored with a first color by a hydrochromic ink. If moisture is present in the pressurized gas above an acceptable level, then the hydrochromic ink turns clear and the cap insert 42 changes color to the second color to indicate that there is an excessive amount of moisture on the pressurized gas side of tank 10. If the moisture in the pressurized gas is at an acceptable level, then the hydrochromic ink does not change and the cap insert 42 displays the first color to indicate that the amount of moisture on the pressurized gas side of tank 10 is acceptable.

The present design helps an owner and / or plumber to visually inspect tank 10 on a more regular basis without having to remove tank 10 from the system. As a result, the plumber or owner can be more proactive with maintaining the equipment in use. The present gauge 30 can also be beneficially easily adapted to any existing tank that has a common valve, for example, a Schrader style air valve, which is found on all expansion tanks. As a result, indicator 30 can simply be attached to tank 10 around valve 50 without any modification to the design of tank 10 itself needing to be made.

Additionally, according to various modalities, the indicator can be adapted with the appropriate electronics / software to issue an alert to an email address, cell phone or smart phone to alert the user if moisture has been detected.

Although particular embodiments of the present invention have been illustrated and described, it will be obvious to those skilled in the relevant art that changes and modifications can be made without departing from the invention in its broader aspects. Therefore, the purpose of the appended claims is to cover all changes and modifications that are within the spirit and scope of the invention. The matter set forth in the foregoing description and the accompanying drawings is offered by way of illustration only and not by way of limitation. The actual scope of the invention is intended to be defined in the claims below when viewed in their proper perspective based on prior art.