X-ray Inspection Method for Multiple Small Diameter Pipe Girth Welds Side by Side
A detection method and small-diameter tube technology, which is applied in the field of X-ray detection of metal welds, can solve problems such as easy missed detection, and achieve the effect of improving detection efficiency
Active Publication Date: 2014-10-29
MAANSHAN MCC17 ENG TECH CO LTD
View PDF10 Cites 0 Cited by
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
Because these small-diameter pipes are fixed at the construction site and the distance is small, if the traditional detection method is used, the girth weld of a small-diameter pipe can only be vertically illuminated by one negative film, which cannot meet the requirements of the relevant national standards (according to GB / The T3323-2005 standard stipulates that the double-wall double-shadow transillumination process should be adopted, and each welding joint should be divided into at least two sections of transillumination, with an interval of 90°), especially for some harmful defects that are easy to miss
Method used
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View moreImage
Smart Image Click on the blue labels to locate them in the text.
Smart ImageViewing Examples
Examples
Experimental program
Comparison scheme
Effect test
Embodiment Construction
[0019] Outer diameter D 0 =60mm small-diameter tube as an example, since the welding joints of each row of tubes are in a straight line, the tube-center spacing of water-cooled wall tubes (Φ60×5mm) is 110mm. Let A and B be the focal points of the ray machine, and C be the midpoint of the line connecting the two welds. The centers of the rays emitted by the two focal points of A and B intersect at point C and make them perpendicular to each other. Take F=AC=BC=650mm, Then L 0 =142mm, O 1 C=O 2 C=55mm, the angle between the center of the ray and the line connecting the two cores is 45°.
[0020] exist figure 2 △AO 1 In C:
[0021] AO 1 =√O 1 C 2 +AC 2 -2O 1 C·ACcos45°=612mm.
[0022] exist figure 2 △AO 2 In C:
[0023] AO 2 =√O 2 C 2 +AC 2 -2O 2 C·ACcos135°=690mm.
[0024] The distance difference AO between the X-ray machine and the two welds 2 -AO 1 =78mm. The focal lengths from the rays emitted from focus A or focus B to the two welds are both greater...
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More PUM
Login to View More Abstract
The invention provides an X-ray detection method of many side-by-side small-diameter tube circumferential welds, and belongs to the technical field of the X-ray detection of metal welds. The detection method comprises the following steps: selecting a transillumination focal length F of 600-700mm, determining an eccentric distance L0, determining a primary transillumination direction through translating an X-ray machine to make the distance from an X-ray source center point A to the lower edge of circumferential welds be L0, selecting an image quality agent and a cloth sheet, determining the exposure value, carrying out primary and secondary transillumination, carrying out darkroom treatment after the transillumination, and carrying out quality evaluation. Compared with traditional detection methods, the method provided by the invention has the advantages of reflection of the practical quality of the welds and improved detection efficiency, so requirements of Chinese relevant standards are satisfied.
Description
technical field [0001] The invention belongs to the technical field of X-ray detection of metal welds, and in particular relates to an X-ray detection method for a plurality of small-diameter pipe girth welds arranged side by side. Background technique [0002] Industrial medium and small-diameter pipes (20mm≤Φ≤89mm) mostly belong to medium and high pressure pipelines. These pipelines have been operating in high pressure, high temperature and corrosive media for a long time, and the working conditions are poor. Therefore, the quality of on-site welding is high, and X Radiographic inspection. Because these small-diameter pipes are fixed at the construction site and the distance is small, if the traditional detection method is used, the girth weld of a small-diameter pipe can only be vertically illuminated by one negative film, which cannot meet the requirements of the relevant national standards (according to GB / The T3323-2005 standard stipulates that the double-wall double...
Claims
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More Application Information
Patent Timeline
Login to View More Patent Type & Authority Patents(China)
IPC IPC(8): G01N23/04
Inventor 吴立陈波王孝平
Owner MAANSHAN MCC17 ENG TECH CO LTD