What is 6GR?
The letter R means restriction. in the ‘6GR’ term, ‘R’ means the Restriction Ring. The main difference between a 6G Welding position & 6GR welding position are the: 6GR Position uses a restriction ring above the groove as shown in the below figure. This restriction ring is tack welded to the upper side pipe.
What is 3G 4G 6G welding?
The positions of groove welds are divided into 1G, 2G, 3G, 4G, 5G and 6G, respectively indicating flat welding, horizontal welding, vertical welding, overhead welding, horizontal fixed welding of pipeline and 45 °inclined fixed welding of pipeline.
What is root pass?
Root Pass – The first weld bead placed in the weld joint in a multi-pass weld. Fill – Also referred to as a fill pass, it is the amount of weld bead necessary to fill the weld joint. This pass comes after the root pass and before the cap pass (see next). In some applications, multiple fill passes are necessary.
What is a 5G weld?
In the 5G welding position, the pipe is in the horizontal position. Unlike the 1G position, the pipe is in a fixed position and it cannot be rotated. The welder moves around the pipe in the vertical direction to perform the welding.
What is the easiest position to weld?
flat position weld
Also referred to as a “downhand” position, the flat position weld is the easiest and often the first weld that new students learn. The metals to be joined are placed flat, and the welder passes the electric arc over them, moving across the workpiece in a horizontal direction.
What is the hardest welding position?
Overhead The overhead position weld is the most difficult position to work in. The welding will be performed with the two pieces of metal above the welder, and the welder will have to angle him or herself and the equipment to reach the joints.
Why root pass is important?
The root pass consists of the first weld bead deposited in a groove. Deposition of a root pass requires a greater ability of the welder, since it must guarantee penetration, consistently and without perforations. The aspect and quality of a root pass are dependent of the forces that act directly on the weld pool.
What is hot pass?
A hot pass is a term used in stove-pipe welding, when the bead is complete it is given a quick clean up with a grinder then the hot pass follows, it burns out the slag that is trapped at the junction between the bead and the pipe wall, the slag is often called wagon tracks.
Why are some joints back gouged?
Back gouging is a process of cutting a groove in the back side of a joint that has been welded. Back gouging can ensure 100% joint fusion at the root and remove discontinuities of the root pass. This process can also remove the root pass metal if the properties of the metal are not desirable to the finished weld.
What is the hardest welding test to pass?
6G pipe weld
The 6G pipe weld is one of the most difficult weld certification tests to pass because the pipe is at a 45-degree angle and immovable. Welders performing the 6G certification test must weld in all positions including horizontal, vertical and overhead, and may have to weld both right-handed and left-handed.
What is the easiest welding position?
the flat position weld
What technique is helpful to create a good root pass?
There are two common methods for back purging a pipe root pass weld zone: purging the whole volume of a long pipe run or locally purging the immediate volume around the weld zone. A ratio of about 4:1 between the back flow purge rate and the welding torch flow rate is needed to make a sound root pass weld.
What is root pass and hot pass?
A root bead and hot pass are generally the minimum amount of weld that must be done before the crane / side boom etc can be released and the weld can then be left to completely cool and be filled and capped at a later time / date.
What is the first stage of the hot pass?
Hot pass: The weld pass that immediately follows the stringer (root) pass. HOT PASS had different opinion and they are as below mentioned. It is to fill the weld bevel. It is to Melt and float out the wagon tracks left after the root pass.
What is weld pass?
Weld pass. A single progression of welding along the joint. The result of a pass is a weld bead.