Processing And Quality Control Of Brewery Beer Equipment-Welds And Welded Joints

Processing and quality control of brewery beer equipment-welds and welded joints

“Welded seam” and “welded joint” are two different concepts.
“Welding seam” refers to the joint part formed by welding of a weldment, while “welded joint” is a joint that is made up of two or more parts by welding or has been welded together. The mutual influence of different parts such as weld seam, fusion zone, heat-affected zone and even base metal should be considered in the inspection of welded joint performance.
Weld types are divided into five types: butt weld, fillet weld, plug weld, slot weld and end weld.
Welded joint types are divided into: butt joints, T-shaped joints, cross joints, lap joints, plug welded lap joints, slot welded joints, corner joints, end joints, casing joints, diagonal butt joints, crimped joints, There are 12 types of lock bottom joints.

Classification of test pieces

The classification object of the welding procedure qualification test piece is the welded seam instead of the welded joint. From the perspective of welding, pressure vessels of any structure are composed of various welded joints and base materials, regardless of which welded joints are connected by welds, and welds are the basis for different forms of welded joints. .

The performance of the welded joint is determined by the welding process of the weld. Therefore, the classification object of the welding procedure qualification test piece is the weld instead of the welded joint. In the NB/T 47014 standard, the form of the welding procedure qualification test piece is divided into butt weld test And fillet weld test pieces, and their scope of application is specified.

No provision is made for the welding procedure qualification of plug welds, slot welds and end welds. Welding procedures qualified for butt welds or fillet weld specimens are not applicable to plug welds, slot welds and end welds, but welding procedures qualified for butt weld specimens are also applicable to fillet welds. Starting from the mechanical performance criteria.

Form relationship between butt welds, fillet welds and welded joints
See the figure below for an example of the relationship between butt welds, fillet welds and welded joints.

From the perspective of welding procedure qualification test piece classification, it can be seen that:

(1) Butt welds are not necessarily all butt joints; fillet welds are not necessarily all corner joints. Although the welded joints are of different forms, the weld forms connecting them can be the same. In other words, the same weld form can be different welded joints.

(2) Regardless of the welded joint form of the weldment, as long as it is connected by butt welds, only the butt weld test piece is required to qualify the welding process; and regardless of the welded joint form of the weldment, as long as it is connected by fillet welds , Fillet weld test piece or butt weld test piece can be used for welding procedure qualification.

(3) The qualified welding process of the butt weld test piece can be used for the butt weld and fillet weld of various welded joints in the weldment; the qualified welding process of the fillet weld test piece can be used for the non-pressure weldment. Fillet welds of various welded joints, such as the fillet welds between the support plate and the shell of a horizontal vessel.

(4) The form of the weld is one of the key factors to determine the welding procedure qualification items.
When determining the welding procedure qualification items, firstly, on the drawing, look for the various types of welded joints to be connected by which form of welds, and decompose the welded joints into welds.

As long as the welded joints are connected by butt welds, test pieces of butt welds are to be made. The welding process qualified for butt weld test pieces is also applicable to fillet welds. When the welding process of non-pressure fillet welds is evaluated, only angles can be used. Weld test piece.

For example, the non-pressure fillet weld between the support plate and the shell of the horizontal container, the butt weld test piece has two kinds of plate and pipe. These two kinds of test pieces have the same measurement of the mechanical properties of the welded joint. There is no difference in principle. The NB/T 47014 standard stipulates that the qualified welding process of the plate butt weld test piece is suitable for the butt weld of the pipe, and vice versa.

The T-shaped joint shown in the figure below can be decomposed into a combined weld of butt weld and fillet weld. When the welding procedure is qualified, only the butt weld test piece is used for the qualification, and the qualified welding procedure is also applicable. Fillet welds in combined welds.

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