Guide: How To MIG Weld Pipe
Many of the building and repair activities would need you to weld pipes together. In order to build a quality weld for pipes using a MIG welder, you need a complete understanding and knowledge of weaving technique. Then you can easily weld bead properly.
A solid and strong weave building is basic for welding pipe technique . Once you know the technique you will appreciate and use it for varied projects and purposes. You may have the need of welding high pressure pipe or high purity pipe for varied industries related to food and beverages.
You may also need to weld pipe for oil, gas industries. No matter what kind of pipe welding you need to do basic techniques would remain same.
Pipe Welding Techniques:
While dealing with the process of MIG welding pipes, you would need to adopt a variety of processes. These include improper shielding gas, drive rolls, low amperage rating of MIG gun and more. With the increasing advancement, more and more welders are now adopting methods of dealing with various new pipe materials.
These methods are improving the quality of weld along with an increase in productivity and safety of user and material. Some basic factors must be taken in to account that can affect pipe welding process. Thus here we will share some basic tips that would enable you to give pipes a strong quality weld.
MIG Welding Pipe:
In order to deal with pipe welding using a MIG gun with root run being at the position of 12 in your clock. The welder needs to make sure that the gun is not positioned at too acute angle to the pipe to be welded. If this is the case there will be porosity because of gas shielding in welding process and thus would cause a deflection.
One of the major problems with MIG welding pipes is the excess of penetration that appears at the beginning of welding.
In order to avoid that you should have your MIG welding gun at a 30 degrees trailed angle position. Until the entirely opposite position is reached such as 6 in clock, trailing angle must be held between 10 to 20 degrees.
An approximate 9 to 12 mm of distance from work to nozzle should be maintained during the process of welding. The root gap of the pipe is then weaved with the use of gun through the welding process.
An important consideration should be travel speed which should be set such that wire tip arcs on weld pool leading edge so that you do not get defective root runs. A welder must take care and prevent weld pool from flooding the arc as results could be root fusion or penetration.
A sudden increase the speed of travel can cause penetration bead inside the pipe in the form of a range of small length wires termed as whiskers.
Overcoming this state would be difficult that can easily occur at any point of restart position. To prevent that from happening, restart position must be feather grounded.
Useful Tips For Pipe Welding:
1. Burn through, lack of fusion, porosity, and many other defects can happen if you forget to grind the joint before beginning the welding process. This process should be done after oxyfuel or plasma cutting. A welder must ensure that all the oxides are removed from pipe both inside and outside.
2. If you are working with pipes made up of a material prone to distortion such as stainless steel, you should properly cut corners in order to ensure a proper fit without any gaps.
Any gaps in such materials can cause distortion and excessive penetration. If you deal with pipe welding and cutting excessively, it is best to buy a particular pipe cutting tool such as band saws, chop saws etc. to ensure precise cuts.
3. Failing to recall to cutting out and feathering can give you risk of weld defects. Remember to cut out and feather in order to ensure consistent welds.
4. Excess of shielding gas can cause a number of issues such as waste of resource, cost expense, agitation increased and more. Avoid it.
5. It is best to get gases that are already mixed. Do not prefer mixing them with the use of flow regulators.
6. As you change wires of your MIG welding machine, it is important to change type or size of drive roll too.
7. Different processes of MIG welding would need different size and type of nozzles. Match and opt for a nozzle appropriate for your specific pipe welding job.
8. During the peak pulsing cycle, amperage can get raised to a considerably higher level and your MIG gun may not be able to handle that excess amperage.
So make sure you buy a MIG gun capable of handling excessive amperage during the process of pulsing and can also deal with mixed gases. Otherwise gun may burn out quickly.
9. Do not go for complex automated MIG welders rather look for a machine that is capable of handling your jobs. A welder with a 250 amp power is good enough to handle varied pipe welding applications with its power and capacity.
However, it completely depends upon your requirement. You may also get a machine with lower duty cycle and performance in case of dealing with small welding operations.
A consistent and strong pipe welding is possible with a good quality MIG welding machine. You can make this machine work for hours for you for all day long pipe welding and other applications. However, in order to ensure longevity and performance, let the machine to rest for some time.
The robustness that is required in any welding application can be ensured by adopting proper methods and process of welding. MIG Welding machines now offer multi-processing capabilities and thus for all important pipe applications, you will find your MIG welding machine working appropriately.