Pipe Welding Positions: 1G, 2G, 5G, and 6G

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Pipe Welding Positions are referred to as the combination of the different positions of the welder and the job or specimen. Pipe welds are made under many different requirements and in different welding situations as per the job nature. In general, the position of the specimen is fixed, but in many cases, it can be rolled or inclined.

In this article, we will learn about the 4 different types of pipe welding positions, basics consideration for welding, weld joints inspection, etc.

Different Pipe Welding Positions

There are mainly four types of pipe welding positions-

• 1G &#; Horizontal Rolled Position
• 2G &#; Vertical Position
• 5G &#; Horizontal Fixed Position
• 6G &#; Inclined Position

1G &#; Horizontal Rolled Position

In the 1G welding position or Horizontal rolled position, the pipe will be in the horizontal position, and it can be rotated along the horizontal (X) axis. The welder&#;s position remains stationary, means a welder performs the welding at a single plane or point, and the pipe is being rotated slowly.

If the pipes are smaller in size, it can be rotated manually otherwise, equipment is used to rotate the pipe. Welding is performed on the top surface of the pipe. This is the most basic pipe welding position that can be performed. Refer the below image (2 red color spools are welded with a blue color seam)

2G &#; Vertical Position

In the 2G pipe welding position, the pipe will be in the vertical position and it can be fixed or can be free to rotate along the vertical (Y) axis. The welder&#;s position can also remain stationary or can move around the vertical pipe. Welding is performed on the side surface of the pipe in a horizontal direction.

5G &#; Horizontal Fixed Position

In the 5G pipe welding position, the pipe will be in the horizontal position. Unlike the 1G weld position, the pipe will always remain fixed, and it can not be rotated. The welder moves around the pipe outer surface in the vertical direction to perform the welding.

6G &#; Inclined Position

In the 6G pipe welding position, the pipe is at the slope or incline, approximately 45° from the horizontal (X) axis or from the vertical (Y) axis. The pipeline can be in a single or double offset.

The pipe will be in a fixed position, so the welder needs to move around the pipe to perform the welding. This is an advanced pipe welding position that requires an experienced welder and an expert consultation.

Welder&#;s Qualification

In untrained hands (means a less qualified welder), welding could be a safety hazard. That is why standard organizations such as ASME, AWS, ISO, ASNT etc. have made the rules and classifications for welding positions, techniques, and procedures.

The welders must be certified in that particular weld position to perform defect-free welding. A welder&#;s mastery for each welding position is identified by qualification certificates and the live test. The certification qualifies him or her to perform more types of welding work.

In other words, mastery over each position levels up a welder&#;s qualifications and expertise. For example, if a welder having only a 1G position qualification, he cannot perform welding in more advanced positions such as 2G, 5G, or 6G.

But, If a welder having a 6G position qualification, then he or she is permitted or qualified to deliver welding in the 1G, 2G, and 5G positions. These standards must be maintained in order to achieve error and hazards-free work environment.

ASME &#; American Society of Mechanical Engineers
AWS &#; American Welding Society
ISO &#; International Organization for Standardization
ASNT &#; American Society for Non-Destructive Testing

Codes and Standards Related to Pipe Welding

Followings are the major codes & standards related to pipe welding and inspection-

• API 570 &#; For piping inspection
• API &#; For pipelines and related facilities
• ASME B31.1 &#; For power piping
• ASME B31.2 &#; For fuel gas piping-material
• ASME B31.3 &#; For process piping
• ASME B31.4 &#; for liquid transportation Systems for hydrocarbons
• ASME B31.5 &#; For piping refrigeration
• ASME B31.8 &#; For gas transmission and distribution piping
• ASME B31.9 &#; For building services piping
• AWS D10.12 &#; Pipe welding (mild steel)
• AWS D10.18 &#; Pipe welding (stainless steel)

Pipe welding Inspection

There are a number of ways in which you can test the strength of the pipe welding and the quality of the welds. You can also check the surface defects of weld joints.

• Visual Inspection
• Liquid Dye Penetration
• Ultra-sonic Inspection
• Radiography Testing
• Magnetic Particle Inspection

Visual Inspection

Inspecting the weld joint visually is one such method, which is most cost effective , quickest, and easiest. It involves nothing quite watching the weld to discern its quality, which may be a really subjective process. It can&#;t be used as a reliable method for detecting internal weld defects, so this method is especially used when poor quality welds won&#;t put anyone or anything in problem.

Liquid Dye Penetration

Liquid dye penetrant testing is the second method of the weld test, where a dye is sprayed or brushed onto the surface of the metal. The dye will highlight any surface cracks or imperfections that aren&#;t visible to the eye, making it simpler than a visible inspection, although the value of the dye does mean that it&#;s marginally costlier.

Ultra-sonic Inspection

Ultrasonic nondestructive testing also referred to as ultrasonic NDT or just UT, is a method of characterizing the thickness, internal structure, or grain of a test piece through the utilization of high-frequency sound waves. The frequencies, or pitch, used for ultrasonic testing are repeatedly above the limit of human hearing, most ordinarily within the range from 500 kHz to twenty MHz.

Radiography Testing

X-ray testing is the only really practical method of detecting internal weld defects, which is why it is used on jobs where the standard of the weld is vital for safety reasons. It works very similar to X-rays, which we have on the physical body to see the broken bones, except on a way grander, more industrial scale. As a result, there are some risks related to this method, so it should only be administered by trained professionals. It is a particularly effective way of checking weld quality which is why it&#;s used for several pipe welding jobs, but it&#;s the foremost expensive method by an extended shot.

Magnetic Particle Inspection

Magnetic particle inspection is a non-destructive inspection method that gives detection of linear flaws located at or near the surface of ferrous materials. It is not advisable to use for non-ferrous materials. it is viewed primarily as a surface inspection method.

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References
www.magnumndt.com
www.austgen.com.au
www.asme.org
www.aws.org
www.asnt.org

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A welding position is a technique by which a welder joins the metals in positions or angles. The welding position is very important as it affects the flow of molten filler material. It&#;s desirable that the welding operator understands the types of welding positions to smoothly accomplish the task. Also, at a certain position of the welder different welding processes are performed. In this article, we will learn about the common welding positions used in the industrial application of welding.

The guidelines and limitations regarding welding positions in WPS are covered in Section IX of the ASME Boiler and Pressure Vessel Code.

Types of Welding Positions

Some welding processes can be performed at all positions; while some are possible in one or two positions only. According to the positions of the welding joint on sections, the American Welding Society (AWS) and ASME define four types of welding positions. They are

• Flat welding position
• Horizontal welding position
• Vertical welding position, and
• Overhead welding position

The welding position is defined by a number (1 to 6) followed by one letter from F, G, or S. Here, the letter &#;F&#; stands for fillet welding, &#;G&#; denotes Groove welding, and &#;S&#; refers to Stud welding.
The numbers denote welding positions as follows:

• &#;1&#; indicates a flat position. For example, 1F, 1G or 1S
• &#;2&#; refers to a horizontal welding position; Example 2F, 2G or 2S
• &#;3&#; denotes a vertical position; for Example 3F or 3G
• &#;4&#; denotes an overhead position; for Example, 4F, 4G, or 4S.
• Letters &#;5&#; and &#;6&#; are specifically used for piping welding positions in a horizontal fixed position and inclined position respectively. Pipe welding positions will be discussed toward the end of the article.

The following table shows the various welding symbols for welding positions used for different types of welding methods

For more information, please visit Welded Pipe.

Welding Position SymbolWelding PositionWeld Type1 FFlat positionFillet weld1 GFlat positionGroove weld1SFlat positionStud Weld2 FHorizontal positionFillet weld2 GHorizontal positionGroove weld2SHorizontal positionStud Weld3 FVertical positionFillet weld3 GVertical positionGroove weld4 FOverhead positionFillet weld4 GOverhead positionGroove weld4SOverhead positionStud WeldTable 1: Welding position symbols with respect to Welding types

Welding Positions 1G or 1F (Flat welding positions)

In Flat Welding position 1G or 1F, the welding is done from the top side of the joint. The head of the welder remains above the test coupon and the weld face is approximately horizontal. The flat welding position is easier and faster and the molten metal is drawn downward. A flat welding position is also known as a down-hand welding position.

The following image in Fig. 1 shows the welding positions used during welding.

Fig. 1: Weld Joint Positions for plate

Welding Positions 2G or 2F (Horizontal welding positions)

In the horizontal welding position, the weld axis is almost horizontal. Compared to a flat welding position, this is a more difficult position for welding.

Welding position 2F is for a fillet weld where the welding is performed on the upper side of a horizontal surface and against an approximately vertical surface keeping to welding torch at a 45-degree angle.

Welding position 2G is for a groove weld when the welding face lies in an approximately vertical plane with the weld axis in a horizontal plane.

Welding Position 3G or 3F (Vertical welding positions)

In vertical position welding, the weld axis is almost vertical. Both the weld and the plate will lie vertically. For welding vertical surfaces, the molten metal runs downward by gravity and piles up. Welding in an upward or downhill vertical position can resolve this problem. Also, by pointing the flame upward at around a 45-degree angle to the plate, the metal flow can be controlled. Welding position 3G is used for groove welding and 3F is used for fillet welding.

Welding Position 4G or 4F (Overhead weld position)

When the welding is done from the underside of the joint, it is known as the overhead welding position. It&#;s the most difficult position for a welder to work and the most complicated one. Welding Position 4G refers to groove welding and 4F indicates fillet welding.

In overhead welding positions, the metal deposited tends to drop or sag on the plate which results in a bead with a high crown. To get rid of this difficulty, the molten puddle should be kept small. When the puddle becomes too large, one can remove the flame momentarily for the molten metal to cool.

Pipe Welding Positions

The above-mentioned welding positions, i.e, flat, horizontal, vertical, and overhead are the most basic types of welding positions used for plate welding. However, these do not completely describe pipe welding positions. As far as pipe welding is concerned, there are four types of piping welding positions. They are:

• Horizontal Rolled Pipe Weld Position 1G
• Vertical Position 2G
• Horizontal Fixed Position 5G, and
• Inclined Weld Position 6G

Pipe Welding Positions 1G

Welding Position 1G is the easiest pipe welding position as the pipe is in a horizontal position. In a 1G pipe welding position, the pipe can be rotated against its horizontal axis (X-axis). The welder performs pipe welding from the top without changing his position while the pipe is slowly rotated manually or by equipment. Pipe Weld Position 1G is the most basic pipe welding.

The image in Fig. 2 below explains all the pipe welding positions.

Fig. 2: Pipe Welding Positions

Pipe Welding Positions 2G

In pipe welding position 2G, the pipe will be in the vertical position (Pipe axis in the Y direction) and the weld axis in the horizontal direction. The welder performs the welding from the side by remaining stationary or moving around the pipe. The welding method is easy in the case of a 2G pipe welding position and is most frequently welded by the backhand method.

Welding Positions 5G

Pipe welding position 5G is a weld position where the pipe axis is fixed in a horizontal position and the operator weld vertically either downward or upward. In this welding position, the pipe is kept fixed and can not be rotated, unlike 1G welding. 5G welding position is difficult as the pipe can not be rotated.

Welding Positions 6G

In pipe welding position 6G, welding is performed in a sloping pipe. The pipe slope is normally 45 degrees from a horizontal or vertical axis. 6G welding positions, being the most difficult pipe welding positions, require certified and highly experienced welders. The pipe remains fixed and the operator needs to move around the pipe for welding. This is the most challenging and complex pipe welding position for welders.

There is another form known as 6GR where welding is done in a ring mode by placing a steel plate below the weld with a 1-inch gap. This requirement comes while welding pipes near impediments like walls, brackets, or other structures.

Comparisons of welding positions between ISO standard and ASME / AWS standard

Sometimes, the weld positions by professional organization ISO are found in industries. The weld position nomenclature in the ISO system is a bit different. The following table provides a comparison between ISO and AWS standard welding position symbols.

AWS Welding PositionISO Welding Position1G / 1FPA2FPB2GPC4FPD4GPE3G UphillPF3G DownhillPG5G UphillPH5G DownhillPJ6G UphillH-LG DownhillJ-L045Table 2: AWS vs ISO welding positions

Why care about Pipe Welding Positions?

Welding position is one of the most important variables that determine weld quality. For each pipe weld position, welders need to undergo certification processes. If a welder is qualified to weld in a 1G position, he is not allowed to weld hard positions like the 6G position. But on the other hand, if the welder is certified for the hardest 6G position then he can work in the 1G position. So, expertise in each weld position levels up a welder&#;s skills and qualifications.

Frequently Asked Questions related to Welding Positions

1. What are the 5 welding positions?
   As described above, the 5 major welding positions widely used in the welding industry are flat weld, horizontal weld, overhead weld, vertical weld, and piping weld. These welding positions are designated by a number and followed by a letter.
2. What are 5G and 6G welding?
   Weld positions 5G and 6G are pipe welding positions. The 5G is welding in a horizontal fixed position whereas the 6G is welding in an inclined fixed position that is about 45 degrees. Refer to Fig. 2 above for a proper understanding of the 5G and 6G welding positions.
3. How much does a 6G welder make in the United States?
   The salary of welders depends on various factors like the experience of the welder, demand and supply, etc. However, in general, the salary of a 6G welder in the United States varies between $30, 000 to $67,000 per year.
4. Which position is advantageous for easy welding?
   The horizontal welding position is the easiest, safest, and most ergonomic for a welder.
5. How hard is 6G welding?
   The 6G pipe welding is one of the most difficult weldings as the pipe is at a 45-degree angle and immovable. So, only experienced and certified 6G welders can perform these jobs efficiently at the construction site.

Video Courses in Welding

To learn more about welding the following video courses you can refer to:

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