What are the forms of welding grooves and what are the types of grooves for pipeline welding?

Groove - according to the design or process needs, the part to be welded on the weldment is processed and assembled into a certain geometric groove.

The common groove types are: butt groove and corner joint groove (in order to distinguish the butt and general butt welds in the angle joint, it is now divided into three categories: butt, groove angle joint, and corner joint).

The butt groove mainly includes: I-type, V-type, X-type, U-type, Y-type, UV-type, VV type, etc.

Corner bevels include: T-type, lap-joint, J-type, etc.

According to the design or process needs, the groove of a certain geometric shape that is processed and assembled at the part to be welded in the weldment is called groove. The groove is mainly for welding the workpiece, to ensure the degree of welding, under normal circumstances, the profile processed by the machining method, when the requirements are not high, it can also be gas cut (if it is a type of weld, ultrasonic flaw detection is required, then only the machining method can be used), but the oxidation slag needs to be removed, according to the need, there are K-shaped grooves, V-shaped grooves, U-shaped grooves, etc., but most of them are required to retain a certain blunt edge

When the two plates are docked, and one side is beveled, the thickness of the plate is 3 6mm, and the angle of the bevel is 70°; When the thickness of the plate is 7 10 mm and 12 26 mm even, the angle of the groove is 60°; If the bottom surface is to be pasted with a board, the angle of the groove is 50°; If the bevel is opened on both sides, the angle of the bevel is 60°; When the right angle is welded, when the bevel is opened on one side, the bevel angle is 55° when the thickness of the plate is 4 6mm; The thickness of the plate is greater than 7 30mm and the right angle is welded, and the angle of the groove is 60° when the bevel is opened on both sides.

The welding groove is also related to the welding process, the use of automatic welding machine is generally less than 10 mm of steel plate does not open the groove, the use of manual welding more than 3 mm needs to open the groove. The groove forms are sorted according to the plate thickness as straight edge, V, X, single U and double U, etc.

For detailed data, please refer to the manual on welding.

Generally, according to this, the "recommended groove for gas welding, electrode arc welding, gas shielded welding and high-energy beam welding)" can be determined

Ensure that the root is welded through. The groove of steel pipe welding is designed according to the wall thickness, generally using a V-shaped groove, sometimes using a U-shaped groove, and a large-diameter and large wall thickness using X, double U-shaped groove, as well as a composite groove.

The purpose is to make the welded joint achieve full weld penetration and rust removal, so that the weld and the base metal can have equal strength.

It is best to use machining, such as turning, planing or special beveling machine, and if there is no condition, it can be used for flame gas cutting, plasma cutting and then grinding with a sand turbine.

When the thickness of the weldment is equal to or large or the multi-layer multi-pass welding method is 6mm, because the heat of the arc is difficult to make the root of the weld penetrate, it should be beveled or multi-layer multi-pass welding.

In order to ensure the quality of welding, the processing of the workpiece that needs to be welded before welding can be gas cut or cut, generally beveled, sometimes curved surface. For example, two steel plates with a thickness of 10mm should be welded together, and in order to make the weld firm, Huiqing will mill the chamfer at the edge of the plate, which is called beveling. Due to the different material thickness and welding quality requirements, the form of the welded joint and the shape of the groove are not the same, and the general groove form is divided into K type, V type, I type, U type, X type, etc.

Below 6mm, there is no need to open the bevel, but the back should be cleaned to ensure the quality of welding. If it is more than 6mm, it is best to open the groove, and it is difficult to weld through if it is not silver, and the non-destructive testing will not be qualified. In fact, I personally suggest that it is best to open the groove regardless of the thickness of the roll, and carry out argon arc welding to ensure the quality of welding, reduce the repair rate, and improve the pass rate and production efficiency of welding.

1. Mechanical and physical processing.

This method is to carry out groove processing without changing the physical properties of the two pieces of metal steel welded before the groove welding process by professional groove processing equipment (the main point is not to use chemistry, save cooling, and do not change the molecular structure), and the common processing equipment is, groove machine, milling machine, lathe, etc.

2. Processing of acetylene gas cutting groove.

The bevel method of high-temperature melting of oxygen acetylene gas cutting, including manual cutting, semi-automatic and automatic cutting machine cutting, is currently widely used for medium and heavy plates without special flaw detection and other high requirements.

Using welding torches and welding nozzles with different angles, the common Y-shaped groove angle, double-sided Y-shaped groove angle, V-groove angle, and double-sided V-groove angle can be processed on one acetylene gas cutting beveling machine.

Please take a closer look: 1. The groove of the Xiangming elimination pipe.

There are several types of bevels for pipes: I-bevel, V-bevel and U-bevel.

1) I-type groove: The I-type groove is suitable for nozzle welding where the thickness of the pipe wall is below the chain elimination.

2) V-groove V-groove is suitable for medium and low pressure steel pipe welding, the angle of the groove is 600 700, the root of the groove has a blunt edge, and its thickness is about 2mm;

3) U-shaped groove U-shaped groove is suitable for high-pressure steel pipe welding, and the thickness of the pipe wall is between 20 and 60mm. There is a blunt edge at the root of the groove, and its thickness is about 2mm;

2. The processing method of the groove.

The processing methods of the groove are generally as follows:

1) If the nominal diameter of the low-pressure carbon steel pipe is equal to or less than 50mm, the hand-held grinding wheel is used to grind the locust and destroy the groove; If the diameter is greater than 50mm, use oxyacetylene to cut the slope and guess the ant's mouth, and then use the hand-held grinder to remove the oxide layer and polish it flat;

2) Medium pressure carbon steel pipes, medium and low pressure stainless acid-resistant steel pipes and low alloy steel pipes, as well as various high-pressure steel pipes, with lathes to process grooves;

3) Non-ferrous metal pipes, with manual spikes buried file grooves.

1.The position of the groove weld is divided into: 1g, 2g, 3g, 4g, 5g, 6g, 6gr to distinguish, and the subliters of reed do not represent flat welding, horizontal welding, vertical welding, vertical welding, vertical welding, pipeline horizontal fixed welding, pipeline oblique 45 degrees fixed bright eggplant welding, pipeline oblique 45 degrees plus obstacle belt ring condition noise under the 6gr welding.

2.Plate fillet welds are divided into: 1f 2f 3f 4f respectively ship type welding.

Horizontal welding, vertical welding, vertical welding, vertical welding.

3.Tube sheet or fillet welds are divided into: 1F, 2F, 2F, 4F, and 5F, respectively, 45 degree rotary welding, horizontal welding, and horizontal welding of the pipe axis.

The axis of the pipe is welded upward, and the <> is welded horizontally

The following are the steel plate welding groove standards:

Process content: clean up the slag and iron oxide after semi-automatic or manual cutting, and then use a grinder or grinder to smooth the cutting place, and by the way, polish both sides of the cutting place until the metallic luster is exposed, and have assembly and welding conditions.

According to the needs of design or process, the groove that is processed into a certain geometric shape at the part to be welded in the weldment is called groove.

1. The role of the groove.

Its main function is to ensure the penetration of the weld root, so that the welding heat source can penetrate deep into the root of the joint, so as to ensure the quality of the joint. The bevel also plays a role in adjusting the ratio of base metal to filler metal.

2. The size name and marking of the groove.

The blunt edge is to prevent burn-through, and the blunt edge size should ensure that the first layer of weld is welded through. When the root gap is primed, it can ensure that the part is welded through. The groove angle is used to make the arc penetrate deep into the root of the weld, so that the blunt edge is welded through, and it is easy to remove the slag to obtain an aesthetically pleasing weld.

3. Common groove forms.

Commonly used groove forms include I-shaped groove, Y-shaped groove, U-shaped groove with blunt edge, double Y-shaped groove, unilateral V-shaped groove with blunt edge, etc.

4. Selection of welding groove.

The selection of weld grooves generally follows the following principles:

It can ensure the welding penetration of the workpiece, (the penetration depth of hand arc welding is generally 2 4mm), and it is convenient for welding operation. If it is inconvenient to weld inside the container, a single-sided groove should be used to weld on the outside of the container.

The bevel shape should be easy to machine.

Maximize welding productivity and electrode savings.

Minimize the deformation of the workpiece after welding.