Device and method for detecting leakage of in-use gas cylinder

Abstract

The invention relates to the technical field of gas packaging containers, in particular to a device and a method for detecting leakage of an in-use gas cylinder. According to the gas cylinder leakage detection device, in the time period when the gas cylinder does not provide gas to the outside, after the valve block comprising the cylinder valve connector, the connector nut, the pressure detection device, the safety device and the pressure release valve is additionally arranged at the in-situ valve outlet of the gas cylinder with the valve, gas cylinder leakage and valve element leakage can be detected according to the pressure detection device or the safety device.

Description

An apparatus and method for leak detection of in-use gas cylinders Technical Field

[0001] This invention relates to the field of gas packaging container technology, and in particular to an apparatus and method for leak detection of in-use gas cylinders. Background Technology

[0002] Leak detection of in-use gas cylinders is a routine gas cylinder maintenance procedure. Gas leaks can generally be divided into two categories: valve core leaks and cylinder leaks. Cylinder leaks can include leaks in the cylinder body, leaks in the valve stem of the in-situ valve (i.e., the valve that comes with the gas cylinder), and leaks at the threaded connection between the in-situ valve and the cylinder body.

[0003] In related technologies, whether a gas cylinder in use has leaked is usually checked using airtightness testing. These methods require specialized equipment and time for dedicated personnel to observe the leaks. However, in most cases, there is no traditional airtightness testing equipment or dedicated personnel available at the gas cylinder's site.

[0004] Therefore, there is an urgent need to provide a device and method for leak detection of in-use gas cylinders to solve the above-mentioned technical problems. Summary of the Invention

[0005] This invention provides an apparatus and method for leak detection of in-use gas cylinders, which can detect whether there is a gas leak in the in-use gas cylinders.

[0006] In one embodiment, the present invention provides an apparatus for leak detection of in-use gas cylinders, comprising a cylinder valve connector, a connector nut, a valve block, a pressure detection device, a safety device, and a pressure relief valve. The cylinder valve connector is connected to the in-situ valve of the in-use gas cylinder to be leaked via the connector nut. The cylinder valve connector, the pressure detection device, the safety device, and the pressure relief valve are respectively connected to cavities within the valve block. The pressure detection device is used to detect the gas pressure within the cavity. The safety device is used to activate when the gas pressure within the cavity exceeds a preset pressure. The pressure relief valve is used to release pressure from the cavity.

[0007] Preferably, the pressure detection device is a pressure sensor or a pressure gauge.

[0008] Preferably, the safety device is a rupture disc device.

[0009] Preferably, the pressure relief valve is a switch valve.

[0010] In another embodiment, the present invention provides a method for leak detection of in-use gas cylinders, based on the apparatus described in any of the above embodiments. The method includes: Step S1, detecting gas cylinder leaks: connecting the cylinder valve connector to the in-situ valve of the in-use gas cylinder to be leaked via the connector nut, opening the in-situ valve, measuring the pressure P1 inside the in-use gas cylinder using the pressure detection device, recording the ambient temperature T1 at this time, and closing the in-situ valve; after a certain period of time, opening the in-situ valve, measuring the current pressure P2 of the pressure detection device and the ambient temperature T2, calculating the change in gas inside the cylinder Δn = V(P1 / T1 - P2 / T2), and if Δn is greater than zero given the known cylinder volume V, it indicates a gas cylinder leak; Step S2, detecting valve core leaks: connecting the cylinder valve connector to the in-situ valve of the in-use gas cylinder to be leaked via the connector nut, closing the in-situ valve, and if the pressure detection device has a reading or the safety device activates, it indicates a valve core leak; wherein, during leak detection, the pressure relief valve remains closed. Beneficial Effects

[0011] The apparatus and method for leak detection of in-use gas cylinders provided by the present invention, when the gas cylinder is not supplying gas to the outside, a valve block including a cylinder valve connector, connector nut, pressure detection device, safety device, and pressure relief valve is added to the original valve outlet of the valved gas cylinder. In this way, gas cylinder leakage and valve core leakage can be detected by the pressure detection device or the safety device. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 shows a schematic diagram of a device for leak detection of in-use gas cylinders according to one embodiment. Detailed Implementation

[0014] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0015] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0016] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0017] In the description of this invention, it should be noted that if terms such as "upper," "lower," "inner," "outer," or "middle" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed, they are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0018] As shown in Figure 1, the present invention provides a device for leak detection of in-use gas cylinders, including a cylinder valve connector 1, a connector nut 2, a valve block 3, a pressure detection device 4, a safety device 5, and a pressure relief valve 6. The cylinder valve connector 1 is connected to the in-situ valve of the in-use gas cylinder to be leaked through the connector nut 2. The cylinder valve connector 1, the pressure detection device 4, the safety device 5, and the pressure relief valve 6 are respectively connected to the cavity in the valve block 3. The pressure detection device 4 is used to detect the gas pressure in the cavity. The safety device 5 is used to activate when the gas pressure in the cavity exceeds a preset pressure. The pressure relief valve 6 is used to relieve pressure in the cavity.

[0019] In the above scheme, when the gas cylinder is not supplying gas to the outside, a valve block containing a cylinder valve connector, connector nut, pressure detection device, safety device, and pressure relief valve is added to the original valve outlet of the valved gas cylinder. In this way, gas cylinder leakage and valve core leakage can be detected by the pressure detection device or the safety device.

[0020] Specifically, gas cylinder leak detection is achieved as follows: the pressure P1 inside the gas cylinder in use is measured using pressure detection device 4, the ambient temperature T1 is recorded, and the original valve is closed; after a certain period of time, the original valve is opened, and the current pressure P2 of pressure detection device 4 and ambient temperature T2 are measured. The change in gas inside the gas cylinder Δn = V(P1 / T1 - P2 / T2) is calculated. If Δn is greater than zero given the known gas cylinder volume V, it indicates that the gas cylinder is leaking.

[0021] Valve core leakage is achieved as follows: if the valve is closed in its original position and the pressure detection device 4 has a reading or the safety device 5 activates, it indicates that the valve core is leaking.

[0022] In one embodiment, the pressure detection device 4 is an online pressure sensor or an offline pressure gauge.

[0023] In one embodiment, safety device 5 is a rupture disc device.

[0024] In one embodiment, the pressure relief valve 6 is a switching valve.

[0025] In some embodiments, the gas passage within the valve connector 1 is a gas passage with the smallest possible cross-sectional dimensions, and the cavity within the valve block 3 is a cavity with the smallest possible volume, and the two are interconnected. For example, the gas passage has a diameter of 0.5 mm, and the cavity is a cylinder with a height of 2 mm and a cross-sectional diameter of 2 mm.

[0026] In summary, by installing a gas cylinder leak detection device on a valved gas cylinder, leaks can be detected both online and offline. This solves the problem of leak detection at the gas cylinder usage site for corrosive, toxic, standard, and high-value gases, and is conducive to the rational and safe utilization of gas cylinders and the media stored inside them.

[0027] Furthermore, this invention also provides a method for leak detection of in-use gas cylinders. Based on the apparatus mentioned in any of the above embodiments, the method includes: Step S1, detecting gas cylinder leaks: Connecting the cylinder valve connector 1 to the original valve of the in-use gas cylinder to be leaked through the connector nut 2, opening the original valve, measuring the pressure P1 inside the in-use gas cylinder using the pressure detection device 4, recording the ambient temperature T1 at this time, and closing the original valve; after a certain period of time, opening the original valve, measuring the current pressure P2 of the pressure detection device 4 and the ambient temperature T2, calculating the change in gas inside the gas cylinder Δn=V(P1 / T1-P2 / T2), and if Δn is greater than zero given the known gas cylinder volume V, it indicates a gas cylinder leak; Step S2, detecting valve core leaks: Connecting the cylinder valve connector 1 to the original valve of the in-use gas cylinder to be leaked through the connector nut 2, closing the original valve, and if the pressure detection device 4 has a reading or the safety device 5 activates, it indicates a valve core leak; wherein, during leak detection, the pressure relief valve 6 remains closed.

[0028] For example, by using a gas cylinder leak detector to check for overall leakage in a 10-liter gas cylinder filled with ideal gas, the gas cylinder leak detector is connected to the outlet of the in-situ valve of the valved gas cylinder. The in-situ valve is opened, and the pressure inside the gas cylinder, P1, is measured to be 9.82 MPa using a pressure detection device 4. The pressure inside the cylinder and the ambient temperature, T1, are recorded as 295 K. The in-situ valve is then closed. After 48 hours, the in-situ valve is opened again, and the reading of the pressure detection device 4, P2, is measured to be 9.81 MPa and the ambient temperature, T2, is recorded as 294 K. The change in gas inside the cylinder, Δn, is calculated as Δn = V(P1 / T1 - P2 / T2) = -0.00079. Since Δn is less than zero, it indicates that the gas cylinder has not leaked.

[0029] When detecting valve core leakage on a gas cylinder, both the original valve on the gas cylinder and the pressure relief valve 6 on the detection device are in the closed state. The initial reading of the pressure detection device 4 is 0 MPa. After an interval of 48 hours, there is a reading of 0.02 MPa. This indicates that the gas cylinder valve port is not sealed tightly and there is gas leakage, which means that the valve core is leaking.

[0030] Before removing the entire testing device, open the pressure relief valve 6. After the pressure testing device 4 reads zero, remove the connector nut 2 that is connected to the original valve on the gas cylinder.

[0031] It is understood that the method provided in this embodiment and the apparatus provided in the above embodiments are based on the same inventive concept, and therefore have the same beneficial effects, which will not be elaborated here.

[0032] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus.

[0033] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A device for leak detection of in-use gas cylinders, characterized in that, The device includes a cylinder valve connector, a connector nut, a valve block, a pressure detection device, a safety device, and a pressure relief valve. The cylinder valve connector is connected to the in-situ valve of the gas cylinder to be leaked via the connector nut. The cylinder valve connector, the pressure detection device, the safety device, and the pressure relief valve are respectively connected to the cavity within the valve block. The pressure detection device is used to detect the gas pressure within the cavity. The safety device is used to activate when the gas pressure within the cavity exceeds a preset pressure. The pressure relief valve is used to release pressure from the cavity.

2. The apparatus according to claim 1, characterized in that, The pressure detection device is a pressure sensor or a pressure gauge.

3. The apparatus according to claim 1, characterized in that, The safety device is a rupture disc device.

4. The apparatus according to claim 1, characterized in that, The pressure relief valve is a switch valve.

5. A method for leak detection of in-use gas cylinders, characterized in that, Based on the apparatus of any one of claims 1-4, the method comprises: Step S1, detecting gas cylinder leakage: connecting the cylinder valve connector to the in-situ valve of the gas cylinder to be leaked through the connector nut, opening the in-situ valve, measuring the pressure P1 inside the gas cylinder using the pressure detection device, recording the ambient temperature T1 at this time, and closing the in-situ valve; after a certain period of time, opening the in-situ valve, measuring the current pressure P2 of the pressure detection device and the ambient temperature T2, calculating the change in gas inside the gas cylinder Δn=V(P1 / T1-P2 / T2), and if Δn is greater than zero given the known gas cylinder volume V, it indicates a gas cylinder leakage; Step S2, detecting valve core leakage: connecting the cylinder valve connector to the in-situ valve of the gas cylinder to be leaked through the connector nut, closing the in-situ valve, and if the pressure detection device has a reading or the safety device activates, it indicates a valve core leakage; wherein, during leakage detection, the pressure relief valve remains closed.

Images