Gas sampling bag valve

Abstract

The utility model provides a gas sampling bag valve. The gas sampling bag valve is composed of a valve body and a valve switch knob. The valve is mounted on the sampling bag film in a non-sealing washer fastening mode, and a valve body is directly thermally welded to the sampling bag film. The process of welding the valve main body on the film omits a fastener and a sealing washer, improves the installation efficiency, avoids the problem of gas leakage caused by corrosion of gas to the sealing washer due to a hot melting welding mode, and can prevent the problem of gas leakage of low-molecular-weight gas from a gap between the valve and the film. The installation mode is also suitable for gas sampling bag valves which are made of thermoplastic materials and are of other structures.

Description

Technical Field

[0001] The utility model relates to a gas sampling bag valve. Background Art

[0002] The valves used on the currently known gas sampling bags are usually composed of a valve body, a valve switch knob, a fastener, and a sealing gasket. The fastener is connected to the valve body by threads. The valve body is an internal thread, and the fastener is an external thread. The fastener passes through the hole of the sampling bag film, and the sealing gasket is placed. After the fastener and the valve body are screwed together, the connection between the valve body and the fastener is sealed; or the valve body is an external thread, a sealing gasket is put on, and it passes through the hole of the sampling bag film. The fastener uses a nut to lock the external thread of the valve body. The valve can also be installed on the sampling bag film, so that there is no leakage at the connection between the valve and the film. The threaded installation method may cause the thread to be tightened inconsistently, resulting in the possibility of leakage. There are also direct fasteners that press the sealing gasket and the film to the valve body under a certain external force to fix the valve to the sampling bag film. These valve installation methods all require sealing gaskets; when encountering highly corrosive gases, such as hydrofluoric acid, the silicone rings generally used for sealing rings will be corroded, resulting in leakage; the sealing rings will weaken over time due to extrusion elasticity, and the gas sampling bags will easily leak when storing some low molecular weight gases; the above valve installation methods are relatively inefficient. Summary of the invention

[0003] In order to overcome the problems of existing gas sampling bag valves using sealing rings as sealing means, being corroded or having weak elasticity and being prone to leakage, as well as having low installation efficiency, the present invention provides a gas sampling bag valve, in which the valve is installed on the sampling bag film in a fastening manner without a sealing gasket, and the valve body is directly heat welded to the sampling bag film.

[0004] The technical solution adopted by the present invention to solve the technical problem is: the gas sampling bag valve is composed of a valve body and a valve switch knob. There is a through hole in the center of the valve body, which serves as a gas passage. There are side holes on the valve body, which intersect the through hole vertically. The switch knob is installed on the side hole of the valve body. The connection between the valve body and the sampling bag can be made into a prism or other shapes. The four sides of the sampling bag are sealed, and one side is left with an opening slightly wider than the prism width of the valve body. The prism part of the valve body is inserted into the opening of the sampling bag, so that the prism surface fits the inner surface of the bag, and the valve body is fixed to the sampling bag by heat sealing with a heat welding machine.

[0005] The valve switch knob has a side hole. Insert the valve switch knob into the side hole of the valve body. When the side hole of the valve switch knob is in line with the through hole of the valve body, the valve is in an open state; when the side hole of the valve switch knob intersects vertically with the through hole of the valve body, the valve is in a closed state.

[0006] The process of welding the valve body to the film eliminates the need for fasteners and sealing gaskets, improving installation efficiency. At the same time, because of the hot-melt welding method, there is no need to worry about gas corrosion and leakage of the sealing gasket. It can also prevent low molecular weight gas from leaking from the gap between the valve and the film. This installation method is also suitable for gas sampling bag valves made of thermoplastic materials of other structures. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 It is a cross-sectional schematic diagram of the valve body of the gas sampling bag valve of the utility model.

[0008] Figure 2 The utility model is a schematic diagram of the prismatic welding part between the valve body and the sampling bag of the gas sampling bag valve.

[0009] Figure 3 This is a cross-sectional schematic diagram of the gas sampling bag valve switch knob of the utility model. Implementation

[0010] like Figure 1 As shown, the gas sampling bag valve body 100, the end 101 of the sampling bag heat welding part is a prismatic structure, and other shapes are also possible; in order to better heat-melt weld with the film, the outer surface of the prismatic shape can be processed with some fine lines; there is a central hole in the center of the prismatic shape as a passage for air flow; when installing, the outer surface of the prismatic shape is fitted with the inner surface of the sampling bag film, and the upper and lower layers of the sampling bag film wrap the outer surface of the prismatic shape of the valve body, and heat-seal on a hot-melt welding machine; the inner surface of the sampling bag film and the outer surface of the prismatic shape of the valve body are hot-melted and cooled to form a whole, and the valve body is fixed to the sampling bag. The lateral hole 102 in the middle of the valve body intersects vertically with the central through hole 103 of the valve body, and the lateral hole 102 of the valve body is used to install the valve switch knob 302; the other end 104 of the valve body is used to connect the interface of the external gas source.

[0011] Figure 2 The schematic diagram of the welding part of the gas sampling bag valve body and the sampling bag is a prismatic 101, and 103 is a central through hole.

[0012] Figure 3 The valve switch knob 300 shown has a side hole 301, and the valve switch knob 302 is inserted into the side hole 102 of the valve body. The side hole 301 of the valve switch knob is in a line with the central through hole 103 of the valve body, and the valve is in an open state; when the side hole 301 of the valve switch knob is vertically intersected with the central through hole 103 of the valve body, the valve is in a closed state.

[0013] The valve body 100 becomes an air nozzle by removing the side hole 102. A soft rubber cap is put on the end face near 103 or a plastic cap with a built-in soft rubber gasket is installed on the thread to block the air outlet 103 for use as a switch.

Claims

1. The gas sampling bag valve consists of a valve body and a valve switch knob, and is characterized by: The upper and lower layers of film of the sampling bag wrap the valve body, and the valve body is fixed to the film of the gas sampling bag by hot-melt welding.

2. The gas sampling bag valve according to claim 1, characterized in that: The valve body has a side hole, and a switch knob is installed in the side hole. When the side hole of the switch knob is in a line with the through hole of the valve body, the valve is in an open state. When the side hole of the valve switch knob vertically intersects with the through hole of the valve body, the valve is in a closed state.

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