Vacuum Relief Valve for Railroad Tank Car

A vacuum relief valve for a railroad tank car and methods for using the same to test the vacuum relief valve for leaks without requiring removal of the valve from the railroad tank car are described herein. According to one aspect of the invention, a vacuum relief valve described herein may be inspected for leaks without removing the vacuum relief valve from the railroad tank car by using two or more access openings located on the body of the vacuum relief valve. According to another aspect of the invention, a vacuum relief valve described herein may be inspected for leaks without removing the vacuum relief valve from the railroad tank car by using an opening to an interior cavity of the valve body that is revealed by rotating a cover from a closed position to an open position.

FIELD OF THE INVENTION

The present invention relates to a vacuum relief valve and a method of inspecting the same for leaks without removing the vacuum relief valve from the railroad tank car.

BACKGROUND OF THE INVENTION

Railroad tank cars are frequently used to transport a variety of liquid or gaseous commodities, such as crude oil, acid, fertilizer, polymer, food grain products, and/or other goods or resources. Vacuum relief valves are frequently used on tank cars to automatically allow air into the tank car to prevent vacuum conditions that could damage the tank car. For example, a vacuum may be formed in a tank car due to changes in pressure and/or temperature. Such a vacuum can exert extreme stress on the tank car and, in some cases, even cause the tank car to implode on itself. Vacuum relief valves are used to prevent the buildup of excessive pressure or vacuum that may result in damage to the tank car. For example, when a vacuum forms within a tank car, the vacuum (i.e., the pressure difference) exerts a force on a valve stem of the relief valve that causes the valve stem to move and the valve to open. Air from outside the tank car may then be allowed to enter the tank through the valve in order to relieve the vacuum or otherwise equalize the pressure difference between the inside of the tank and the outside of the tank.

However, the air allowed to enter the tank through the vacuum relief valve may contain debris from the environment particularly from blasting operations to remove paint and rust during the repair of a tank car. This debris can become trapped between the seating components of the vacuum relief valve and may cause leaks from the tank car when there is positive pressure in the tank car. Such leaks must be inspected and repaired before the tank car continues its route.

To ensure vacuum relief valves are in proper working order, the valves must be regularly inspected to ensure there are not any leaks. Conventional methods for inspecting a relief valve on a railroad tank car requires removing the valve from a protective housing, disassembling the valve, and/or otherwise removing the valve from the tank car. These methods are typically expensive and result in a substantial loss of operation time due to the time required to inspect and service the valve. A vacuum relief valve and corresponding inspection method that enable the valve to be inspected for leaks without requiring the valve to be removed from the tank car would be a significant improvement over conventional vacuum relief valves for railroad tank cars.

SUMMARY OF THE INVENTION

Aspects of this disclosure relate to a vacuum relief valve for a railroad tank car and a method of using the same to reduce the risk of potential leaks due to debris that may enter into the vacuum relief valve and to test the vacuum relief valve for leaks without requiring removing the vacuum relief valve from the railroad tank car. In various embodiments, the vacuum relief valve may comprise a valve body comprising a flanged portion and two or more access openings, wherein a base of the flanged portion is in contact with a top or a side of a railroad tank car when the vacuum relief valve is installed on the railroad tank car. In some embodiments, the two or more access openings may be integral to the valve body. In some embodiments, the two or more access openings may be located proximate to a beginning of the flanged portion on the valve body.

In some embodiments, the two or more access openings may extend radially and outwardly from an interior cavity of the vacuum relief valve. In an example embodiment, the two or more access openings may include four access openings equally spaced apart from one another circumferentially on an outer surface of the body of the vacuum relief valve. In various embodiments, the two or more access openings are configured to receive leak detection fluid to enable detection of a leak without removing the vacuum relief valve from the railroad tank car.

In various embodiments, a vacuum relief valve described herein may be inspected for a leaks without removing the vacuum relief valve from the railroad tank car. For example, in various embodiments, leak detection fluid may be injected into an interior cavity of a body of the vacuum relief valve. If no bubbles form at or within an opening of the body of the vacuum relief valve, a determination may be made that there is no leak at the vacuum relief valve. If bubbles do form at or within an opening of the body of the vacuum relief valve, a determination may be made that there is a leak at the vacuum relief valve. In various embodiments, the leak detection fluid may be injected into the interior cavity of the valve body by sealing all but one of two or more access openings located on the body of the vacuum relief valve and injecting the leak detection fluid into the interior cavity of the body of the vacuum relief valve via the one unsealed access openings located on the body of the vacuum relief valve. If it is determined that there is a leak at the vacuum relief valve, the vacuum relief valve may then be removed for repair.

In some embodiments (e.g., when there are not access openings located on an outer surface of the valve body), the leak detection fluid may be injected into the interior cavity of the valve body by sliding a cover selectively attached to a top surface of the vacuum relief valve to an open position to reveal an opening to the interior cavity of the vacuum relief valve, and injecting the leak detection fluid into the interior cavity of the body of the vacuum relief valve via the opening to the interior cavity of vacuum relief valve revealed by sliding the cover to the open position. For example, the cover may be selectively attached to the body of the vacuum relief valve via two or more cover mounting fasteners, and the cover may be configured to slidably rotate about one of the two or more cover mounting fasteners when all but the one of the two or more cover mounting fasteners are removed. If it is determined that there is not a leak at the vacuum relief valve, the cover may be slid to a closed position to block access to the interior cavity of the vacuum relief valve. In some embodiments, the cover may be secured to the body of the vacuum relief valve using a safety cable extending between at least two of the two or more cover mounting fasteners.

In some embodiments, the vacuum relief valve may include a screen assembly comprising an air-filter screen configured to prevent debris from reaching the vacuum relief valve, and a screen cover configured to protect the air-filter screen. In some embodiments, the screen cover may include one or more screen access openings. In some embodiments, the screen cover may include a mesh selected to limit a size of debris particles that can enter into the vacuum relief valve. In some embodiments, the screen cover may be configured to form a debris tight seal when in contact with the body of the vacuum relief valve.

These drawings are provided for purposes of illustration only and merely depict typical or example embodiments. These drawings are provided to facilitate the reader's understanding and shall not be considered limiting of the breadth, scope, or applicability of the disclosure. For clarity and ease of illustration, these drawings are not necessarily drawn to scale.

DETAILED DESCRIPTION

In the following description of various examples of the invention, reference is made to the accompanying drawings, which form a part hereof, and in which are shown by way of illustration various example structures, systems, and steps in which aspects of the invention may be practiced. These aspects are indicative, however, of but a few of the various ways in which the principles of the invention may be employed and the present invention is intended to include all such aspects and their equivalents. It is to be understood that other specific arrangements of parts, structures, example devices, systems, and steps may be utilized, and structural and functional modifications may be made without departing from the scope of the present invention. Also, while the terms “top,” “bottom,” “front,” “back,” “side,” and the like may be used in this specification to describe various example features and elements of the invention, these terms are used herein as a matter of convenience, e.g., based on the example orientations shown in the figures. Nothing in this specification should be construed as requiring a specific three-dimensional orientation of structures in order to fall within the scope of this invention.

The invention described herein relates to a vacuum relief valve for a railroad tank car, methods for reducing the risk of potential leaks due to debris that may enter into the vacuum relief valve, and methods of testing a vacuum relief valve that do not require removing the valve from the railroad tank car. In various embodiments, the vacuum relief valve may comprise a valve body that comprises side walls and a flanged portion, a valve stem, and a biasing component. In various embodiments, the valve stem may be slidably movable with respect to the valve body between an open position and a closed position. The valve stem may be secured in the closed position via the biasing component, which in various embodiments comprises a spring. The biasing component may be configured to maintain a predetermined maximum and/or minimum vacuum pressure within the railroad tank car. In various embodiments, the valve body may include one or more access openings that extend radially and outwardly from an interior cavity of the vacuum relief valve. In various embodiments, the vacuum relief valve may also include a cover selectively attached to the valve body and configured to rotate about a cover mounting fastener. According to one aspect of the invention, a vacuum relief valve described herein may be inspected for leaks without removing the vacuum relief valve from the railroad tank car by using the access opening(s) on the body of the vacuum relief valve. According to another aspect of the invention, a vacuum relief valve described herein may be inspected for leaks without removing the vacuum relief valve from the railroad tank car by using the opening to the interior cavity of the valve body that is revealed by rotating the cover from a closed position to an open position.

The vacuum relief valve and methods of inspecting a vacuum relief valve described herein are described with respect to vacuum relief valves affixed to railroad tank cars. However, it is to be understood that the vacuum relief valve and methods of inspecting the same may be equally applicable in other applications without departing from the scope of the invention described herein. For example, the vacuum relief valve described herein may also be utilized in other applications, such as in other applications involving tanks or other storage containers to which a vacuum relief valve may be installed.

FIG.1depicts a perspective view of an example vacuum relief valve100for a railroad tank car, according to one or more aspects described herein. In various embodiments, vacuum relief valve100may include one or more access openings200, a cover300, and/or one or more other components. In various embodiments, vacuum relief valve100may be configured to allow for its inspection without requiring removal of the valve from the railroad tank car or from a protective housing in which it is affixed. Accordingly, vacuum relief valve100may be designed to minimize the time, cost, and energy needed to inspect for leaks.

In various embodiments, vacuum relief valve100may be installed on a railroad tank car at an opening on top of the railroad tank car. For example,FIG.2depicts an example embodiment in which vacuum relief valve100is installed on a top side of a railroad tank car50, according to one or more aspects described herein. In some embodiments, vacuum relief valve100may be affixed to a fittings flange110, which is positioned over a hole in the top of railroad tank car50. In some embodiments, one or more additional components may also be affixed to fittings flange110, as depicted inFIG.2. Accordingly, fittings flange110may be configured to enable vacuum relief valve100and/or one or more other components to be integrated with railroad tank car50. The one or more additional components affixed to fittings flange110may include, for example, a gauging device, a vapor valve, a liquid valve, a safety valve, and/or one or more other components. In some embodiments, the fittings flange110(and/or vacuum relief valve100) may be protected by a protective housing assembly112affixed to railroad tank car50and configured to both protect and provide access to the one or more components affixed to fittings flange110, as depicted inFIG.2.

FIGS.3A-Bdepict perspective views of vacuum relief valve100, according to one or more aspects described herein. For example,FIG.3Adepicts a perspective view of vacuum relief valve100, andFIG.3Bdepicts a cross-sectional view of vacuum relief valve100as depicted shown inFIG.3Aalong a line A-A′. In various embodiments, the one or more access openings200and/or cover300may be integrated in the valve body120of vacuum relief valve100to allow vacuum relief valve100to be inspected without removing vacuum relief valve100from a railroad tank car (e.g., railroad tank car50depicted inFIG.2). In some embodiments, valve body120of vacuum relief valve100may be substantially cylindrical with a flanged portion at the base to mount vacuum relief valve100to the top or a side of a railroad tank car. As described herein, in various embodiments, valve body120may include at least side walls122and a flanged portion124. In various embodiments, an interior of vacuum relief valve100may have a circular shape (e.g., when viewed from a vertical cross-sectional view. In other embodiments, however, the interior of vacuum relief valve100may be a non-circular, rectangular, polygonal, triangular, oval, or any other combination of appropriate shapes without departing from the scope of the invention described herein.

FIGS.4A-Cdepict various cross-sectional views of vacuum relief valve100, according to one or more aspects described herein. As depicted inFIGS.4A-C, vacuum relief valve100may include a valve body (e.g., valve body120) having at least side walls122and a flanged portion124, a valve stem130, a biasing component140, and/or one or more other components. In various embodiments, flanged portion124may include one or more mounting holes126configured to receive bolts, screws, and/or other types of fasteners used to secure vacuum relief valve100to a railroad tank car. For example, the one or mounting holes126of flanged portion124may be configured to receive bolts, screws, and/or other types of fasteners used to removably attach vacuum relief valve100to a fittings flange110of a railroad tank car. Accordingly, in various embodiments, vacuum relief valve100may be securely attached to a railroad tank car via the one or more mounting holes126of flanged portion124. In other embodiments, vacuum relief valve100may be securely attached to a railroad tank car via flanged portion124using one or more techniques described herein and/or using any other now known or future developed fastening technique. For example, a bolt or rivet fastening configuration may be utilized on a top or side of a railroad tank car to receive the flanged portion124of vacuum relief valve100. While a flanged vacuum relief valve is described herein, it should be understood that any appropriate modification of the flanged portion124may be contemplated and is within the scope of the invention described herein. In various embodiments, side walls122of vacuum relief valve100may form an opening at an end of valve body120opposite flanged portion124. In various embodiments, cover300may be attached to the end of side walls122forming the opening opposite the flanged portion124.

In various embodiments, valve stem130may be mated to and received within an opening of valve body120. As depicted inFIG.4A, in various embodiments, valve stem130may comprise a stem base132and a stem body134that extends upwards within vacuum relief valve100. For example, as depicted inFIG.4A, stem body134may be configured to extend away from stem base132along an axis perpendicular to a wall of the railroad tank car to which vacuum relief valve100is mounted. In various embodiments, valve stem130may be slidably movable with respect to valve body120between an open position and a closed position. In various embodiments, valve stem130may be secured in the closed position via a biasing component140. In various implementations, biasing component140may comprise a spring. For example, biasing component140may comprise a wave spring, a compression force spring, or any other suitable type of spring. In various embodiments, the stem body of valve stem130may include a threaded portion configured to receive a biasing washer142and/or a biasing fastener144. The biasing washer142and/or biasing fastener144may be configured to securely fasten biasing component140to valve body120and/or valve stem130. In some embodiments, biasing component140may be adjusted to maintain a predetermined maximum and/or minimum vacuum pressure within the railroad tank car. For example, biasing component140may be adjusted to between approximately −0.75 and −6 pounds per square inch gauge (PSIG). In some embodiments, the threaded portion of valve stem130may be mated to biasing fastener144using any appropriate configuration. For example, biasing fastener144may be any appropriate fastening component. In an example embodiment, biasing fastener144may comprise a locking nut, as depicted inFIG.4A. In some embodiments, stem base132may include a groove, notch, or other type of depression configured to receive a ring150configured to seal off railroad tank car at vacuum relief valve100when valve stem130is in a closed position. For example, ring150may comprise a quad ring or O-ring configured to form a seal when valve stem130is in a closed position. In some embodiments, ring150may be constructed of an elastomer material that can deform to fill surface imperfections in a groove of valve stem130and the interior of stem body120, thereby enabling tighter sealing of vacuum relief valve100.

As described herein, vacuum relief valve100may be configured to allow for improved control of a process for inspecting the valve when attached to a railroad tank car. For example, vacuum relief valve100may be configured to allow it to be inspected for a potential leak without requiring its removal from the railroad tank car or requiring disassembling any components on the valve or the railroad tank car itself. In various embodiments, valve body120of vacuum relief valve100may include one or more access openings200. In some embodiments, the one or more access openings200may be located proximate or adjacent to the beginning of flanged portion124of valve body120. In various embodiments, the one or more access openings200may extend radially and outwardly from an interior cavity of vacuum relief valve100. For example, the one or more access openings200may extend along a line B-B′, as depicted inFIG.4A. In other embodiments, the one or more access openings200may extend radially and outwardly downward along a curved path. In some embodiments, the one or more access openings200may comprise a cylindrical opening at one or both ends (e.g., the end terminating at the interior cavity of valve body120or the end terminating at the outer edge of side wall122of valve body120). For example, as depicted inFIG.4A, a diameter of one end of one or more access openings200may be the same diameter of the other end of one or more access openings200along a line B-B′. In other embodiments, the two or more access openings200may be a frustoconical opening. For example, a diameter of one end of one or more access openings200may be a different diameter of the other end of one or more access openings200along a line B-B′. In some embodiments, the one or more access openings200may include a surface profile to enhance the flow of the leak detection fluid injected from inside of the side wall122towards the outside of the valve body120.

In order to inspect vacuum relief valve100, a leak detection fluid (or other leak detection substance) may be injected into one of the one or more access openings200. For example, and as described herein with respect toFIG.7, all but one of the two or more access openings200may be plugged or otherwise sealed. A leak detection fluid (or other leak detection substance) may then be injected through the one remaining unsealed access opening200from the outside of vacuum relief valve100. If there is a leak within vacuum relief valves100, bubbles would appear coming out of any of the one or more access openings200indicating that air was escaping into the atmosphere. After inspection of vacuum relief valve100is complete, each of the one or more access openings200may be unplugged or otherwise unsealed and any leak detection fluid (or other leak detection substance) injected may be cleaned and removed.

In an alternative embodiment, vacuum relief valve100may be inspected for a leak by injecting a leak detection fluid (or other leak detection substance) directly into the interior cavity formed by side walls122of valve body120via the opening accessed by rotating (or sliding) cover300to an open position, ss described herein with respect toFIG.8. For example, cover300may be slidably rotated from a closed position to an open position to reveal an opening to the interior cavity of vacuum relief valve100. When leak detection fluid is injected via the opening revealed by sliding cover300to an open position, the interior cavity may be visually inspected for bubbles that would indicate that air was escaping into the atmosphere. After inspection of vacuum relief valve100is complete, cover300may be slidably rotated back to a closed position and secured to valve body120as described herein. In some embodiments, the foregoing method of inspecting vacuum relief valve100for leaks by injecting leak detection fluid directly into the interior cavity via the opening at the top of vacuum relief valve100(i.e., without injecting leak detection fluid into an access opening200) may be utilized in embodiments in which vacuum relief valve100does not comprise access openings200.

In various embodiments, cover300may be affixed to a top side of valve body120(and vacuum relief valve100) using one or more cover mounting fasteners302. For example,FIG.4Bdepicts an embodiment of vacuum relief valve100in which cover300is attached to valve body120via one or more screws302, andFIG.4Cdepicts an embodiment of vacuum relief valve100in which cover300is attached to valve body120via a bolt302. It is to be understood, however, that the one or more cover mounting fasteners302may comprise one or more screws, bolts, and/or any other type of fastener now known or future developed without departing from the scope of the invention described herein.

FIGS.5A-Cdepict various top views of vacuum relief valve100, according to one or more aspects described herein. In various embodiments, the one or more access openings200may include any suitable number of access openings. For example, as depicted inFIG.5A, the one or more accessing openings200may include four access openings200a,200b,200c, and200d. In various embodiments, the one or more access openings200may be equally spaced apart circumferentially around an outer side of valve body120. For example, an angle between neighboring access openings of the four access openings200a,200b,200c, and200dmay be roughly 90 degrees, as depicted inFIG.5A. In some embodiments, a height of each access opening200on side wall122of valve body120(e.g., from a bottom surface of vacuum relief valve100) may be roughly the same for each of the one or more access openings200. In other embodiments, a height of one or more individual access openings200on side wall122of valve body120may be different from the height of one or more other access openings200.

In various embodiments, cover300may be selectively attached to valve body120. For example, cover300may be selectively attached to valve body120via one or more cover mounting fasteners302. As described herein, cover300of vacuum relief valve100may be configured to rotate about a cover mounting fastener302. For example, cover300may be configured to rotate about a single cover mounting fastener302as a pivot point. When cover300is rotated to an open position, as depicted inFIG.5B, an interior cavity of valve body120may be accessed.

When there is no leak, access to the interior cavity of valve body120may be blocked by rotating the cover about the cover mounting fastener302and further securing cover300as described herein. For example, when cover300is in a closed position, cover300may be secured again using one or more cover mounting fasteners302. In various embodiments, cover300may include one or more holes configured to receive a cover mounting fastener302. In an example embodiment, cover300may be configured to receive three cover mounting fasteners302via holes on cover300. In various embodiments, cover300may be further secured using safety cable304that extends between at least two cover mounting fasteners302used to secure cover300to valve body120, as depicted inFIG.5C. In some embodiments, safety cable304may be affixed between two cover mounting fasteners302using at least one ferrule. In some embodiments, safety cable304may represent a tamper evident seal that indicates whether vacuum relief valve100has been accessed or otherwise tampered with.

FIGS.6A-Edepict various views of vacuum relief valve with a screen assembly400, according to one or more aspects described herein. In various embodiments, screen assembly400of the vacuum relief valve100may comprise an air-filter screen404to prevent debris from reaching the vacuum relief valve, a screen cover406to protect the air-filter screen, and one or more filter components that surround the outer edge of side wall122of valve body120to prevent debris entering into the vacuum relief valve through one or more accessing openings200. In addition, a screen cover406described herein may further reduce risk of debris entering into the vacuum relief valve by elevating intake ports to minimize debris concentration in the airflow stream into the vacuum relief valve.

In various embodiments, screen assembly400may be securely attached to valve body120(and vacuum relief valve100) using cover300and one or more cover mounting fasteners302. For example, in some embodiments (e.g., as depicted inFIGS.6A-B), screen assembly400may be slidably inserted from top of valve body120and attached to the valve body via cover300, one or more screws302, and/or sealed with safety cable304. In other embodiments, screen assembly400may be positioned surrounding the valve body120and attached to anywhere outside of valve body by any appropriate fastening configuration. In various embodiments, screen assembly400may be configured to include one or more screen access openings402integrated in screen cover406to allow airflow408to be directed into the vacuum relief valve100through one or more accessing openings200.

FIG.6Cdepicts an exploded view of the vacuum relief valve with a screen assembly400, according to one or more aspects described herein. In some embodiments, air-filter screen404may be made of and/or with any appropriate type of mesh construction with a size of mesh selected to limit the size of debris particles that can enter into the vacuum relief valve. In other embodiments, air-filter screen404may be made of and/or include any appropriate type of wire mesh coupled with one or more filter media layers based on anticipated size of debris particles to be prevented from entering into the vacuum relief valve.FIG.6Ddepicts a perspective view of an example air-filter screen404without a screen cover406that fits and surrounds an outer edge of side wall of valve body120. As depicted inFIG.6C, screen cover406may then be slidably inserted over the air-filter screen404from top of valve body120and attached to the valve body via cover300, one or more screws302, and/or sealed with safety cable304.

FIG.6Edepicts a cross-sectional view of the vacuum relief valve with air-filter screen404and screen cover406(i.e., screen assembly400), indicating a direction of airflow408passing through the air-filter screen404. In various embodiments, airflow408may be directed into the vacuum relief valve through one or more screen access openings402(shown inFIG.6A). Using mesh of air-filter screen404, airflow408directed into the vacuum relief valve may be configured to filter debris when the air passes through the air-filter screen404and enters into the vacuum relief valve. The vacuum relief valve would function the same way with or without the air-filter screen404and screen cover406except that the airflow408that enters into the vacuum relief valve is filtered by air-filter screen404. Filtering the air including debris may greatly reduce the risk of potential leaks due to debris entering into the vacuum relief valve.

In various embodiments, screen cover406may include one or more portions with a vertically varying profile. For example, the vertically varying profile may be present in portion of screen cover406extending along the y-axis. However, in some embodiments, a horizontally varying profile may be present in portion of screen cover406extending along the x- and z-axes to further reduce risk of debris entering into the vacuum relief valve via one or more access openings200. In various embodiments, screen cover406may be made of and/or with any appropriate type of sealing material. In various embodiments, when secured to vacuum relief valve100, screen cover406may be in contact with body120at a bottom edge of screen cover406, such that a debris tight seal is formed by the contact of screen cover406and body120.

FIG.7illustrates an example of a process700for inspecting a vacuum relief valve mounted to a railroad tank car for leaks using access openings on the body of the vacuum relief valve and without removing the vacuum relief valve from the railroad tank car, according to one or more aspects described herein. The operations of process700presented below are intended to be illustrative and, as such, should not be viewed as limiting. In some implementations, process700may be accomplished with one or more additional operations not described, and/or without one or more of the operations discussed. In some implementations, two or more of the operations of process700may occur substantially simultaneously. The described operations may be accomplished using some or all of the components described in detail above with respect to vacuum relief valve100.

In an operation702, process700may include installing a vacuum relief valve on a railroad tank car. For example, the vacuum relief valve may comprise vacuum relief valve100and may be installed and secured to the railroad tank car as described herein. In an operation704, process700may include inserting a plug or otherwise sealing all but one of two or more access openings that are located on the body of the vacuum relief valve and extend into an interior cavity of the body of the vacuum relief valve. In an operation706, process700may include injecting a leak detection fluid into the interior cavity of the body of the vacuum relief valve via the remaining unsealed access opening on the vacuum relief valve. In an operation708, process700may include determining whether one or more bubbles appear at any of the access openings located on the body of the vacuum relief valve. The presence of one or more bubbles formed at any of the access openings would indicate that air was escaping into the atmosphere. In an operation710, process700may include unsealing the access openings located on the body of the vacuum relief valve based on the determination that there is no leak because no bubbles formed at any of the access openings. In an operation712, process700may include removing the vacuum relief valve for repair based on the determination that there is a leak because bubbles formed at any of the access openings. After each attempt to repair the valve, at least operations706and708may be repeated until no bubbles form indicating that there are no leaks in the valve.

FIG.8illustrates an example of a process800for inspecting a vacuum relief valve mounted to a railroad tank car for leaks using an opening revealed by rotating a cover of the vacuum relief valve and without removing the vacuum relief valve from the railroad tank car, according to one or more aspects described herein. The operations of process800presented below are intended to be illustrative and, as such, should not be viewed as limiting. In some implementations, process800may be accomplished with one or more additional operations not described, and/or without one or more of the operations discussed. In some implementations, two or more of the operations of process800may occur substantially simultaneously. The described operations may be accomplished using some or all of the components described in detail above with respect to vacuum relief valve100.

In an operation802, process800may include installing a vacuum relief valve on a railroad tank car. For example, the vacuum relief valve may comprise vacuum relief valve100and may be installed and secured to the railroad tank car as described herein. In an operation804, process800may include sliding a cover of vacuum relief valve to an open position to reveal an opening to the interior cavity of vacuum relief valve. In an operation806, process800may include injecting a leak detection fluid into the interior cavity of the body of the vacuum relief valve via the opening to the interior cavity of vacuum relief valve revealed by sliding the cover to an open position. In an operation808, process800may include determining whether one or bubbles appear within the interior cavity of the vacuum relief valve. The presence of one or more bubbles formed within the interior cavity would indicate that air was escaping into the atmosphere. In an operation810, process800may include sliding cover to a closed position to block access to the interior cavity of the vacuum relief valve based on the determination that there is no leak because no bubbles formed within the interior cavity. In an operation810, responsive to a determination that there is no leak, process800may include closing the path to the valve body by rotating the cover about the cover mounting fastener. In an operation812, process800may include removing the vacuum relief valve for repair based on the determination that there is a leak because bubbles formed within the interior cavity. After each attempt to repair the valve, at least operations806and808may be repeated until no bubbles form indicating that there are no leaks in the valve.

Reference in this specification to “one implementation”, “an implementation”, “some implementations”, “various implementations”, “certain implementations”, “other implementations”, “one series of implementations”, or the like means that a particular feature, design, structure, or characteristic described in connection with the implementation is included in at least one implementation of the disclosure. The appearances of, for example, the phrase “in one implementation” or “in an implementation” in various places in the specification are not necessarily all referring to the same implementation, nor are separate or alternative implementations mutually exclusive of other implementations. Moreover, whether or not there is express reference to an “implementation” or the like, various features are described, which may be variously combined and included in some implementations, but also variously omitted in other implementations. Similarly, various features are described that may be preferences or requirements for some implementations, but not other implementations.

The language used herein has been principally selected for readability and instructional purposes, and it may not have been selected to delineate or circumscribe the inventive subject matter. Other implementations, uses and advantages of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. The specification should be considered exemplary only, and the scope of the invention is accordingly intended to be limited only by the following claims.