We get lots of questions regarding welding pipe. Whether it’s about welding high-pressure pipe, Beveled End Welded Steel Pipes for food and beverage industries, or pipe for the oil and gas industries, there are a variety of common elements we see in pipe welding and fabrication which lead to problems. These include from improper shielding gas and drive rolls to choosing a MIG gun with too low of an amperage rating. As companies push to train new welders, work with new materials, increase quality and productivity, and improve safety, you should concentrate on many of these basic variables in the pipe welding method that can affect these efforts. In this post, we’ll take a look at 13 of the most common issues we have seen in pipe welding applications and the way to resolve them.

1. Forgetting to grind the joint after oxyfuel or plasma cutting

The oxyfuel and plasma cutting processes add a layer of oxide to the cut edge. This oxide layer has to be removed before welding, as the oxide often has a higher melting point compared to the base metal. Once the arc gets hot enough to melt the oxide, it’s too hot for the base metal and can lead to burnthrough. The oxides may also remain in the weld and cause porosity, inclusions, lack of fusion along with other defects. It is essential that welders be sure you grind the joint as a result of the parent material just before welding, along with grind the in and out of diameters in the pipe to remove these oxides along with other potential contaminants.

2. Cutting corners with cutting

When welders work with materials more prone to distortion and the affects of higher heat input, including stainless-steel and aluminum, a bad cut can lead to poor fit-up and make unnecessary gaps. Welders then compensate by putting more filler metal (thus, heat) to the joint to fill it up. This added heat can lead to distortion and, with corrosion-resistant pipe like stainless-steel, is effective in reducing the corrosion-resistant qualities from the base metal. Additionally, it may lead to absence of penetration or excessive penetration. Poor preparation also contributes to longer weld cycle times, higher consumable costs and potential repairs.

Shops currently using chop saws or band saws to reduce pipe used in critical process piping applications should consider buying dedicated orbital pipe cutting equipment to ensure cuts within mere thousandths of your inch of the specified parameters. This precision helps ensure optimum fit-up and keeps the amount of filler as well as heat put into the joint at the very least.

3. Forgetting to reduce out and feather tacks

Tacking is critical to match-up, and finest practices suggest that the welder reduce and feather that tack to guarantee the consistency in the final weld. Particularly in shops when a fitter prepares the Poly Lined Steel Pipe and then somebody else welds it, it’s essential that the welder knows exactly what is incorporated in the weld. Tacks left in the joint become consumed by the weld. When there is a defect within the tack, or maybe the fitter used a bad filler metal to tack the joint, you will find a risk for defects inside the weld. Removing and feathering the tacks helps eliminate this potential problem.

4. Preparing a joint for MIG processes is different compared to Stick welding

Training welders is actually a top priority for many fab shops, and – for better or worse – many welders bring past experiences together to the new job. These experiences may be addressed with adequate training, but one common mistake we see is welders with Stick experience not finding out how to correctly create a joint for wire processes common in pipe fabrication applications. Welders trained traditionally in Stick and TIG welding often prepare the joint using a heavy landing area and wish to keep your gap as narrow as is possible. As pipe shops transition to easier, more productive MIG processes including Regulated Metal Deposition (RMD™), we prefer welders take that landing area as a result of a knife’s edge and space the joint at approximately 1/8-inch. This region is wider as opposed to those trained in Stick and TIG processes are used to and can result in numerous problems: focusing excessive heat into the edges from the weld, an absence of penetration and insufficient reinforcement on the inside of the pipe. Shops should train their welders to the details of each application and ensure they understand different weld preparation and operational techniques before they go to work.

5. More shielding gas may not be better

Some welders use a misconception that “more shielding gas is better” and will crank the gas wide open, mistakenly believing they are providing more protection towards the weld. This method causes a number of problems: wasted shielding gas (resources and expense), increased and unnecessary agitation of the weld puddle, and a convection effect that sucks oxygen in to the weld and can result in porosity. Each station ought to be outfitted with a flow meter and every welder should learn how to set and follow the recommended flow rates.

6. Buy mixed gas – don’t count on mixing with flow regulators

We now have seen shops that, for a stainless steel application that requires 75/25 percent argon/helium, setup a different tank of argon as well as a separate tank of helium and after that count on flow regulators to bleed within the proper amount of shielding gas. The truth is you really don’t know what you’re getting in a mix with this method. Buying cylinders of Galvanized Stainless Steel Pipes from reliable sources, or purchasing a proper mixer, will make sure you understand precisely what you’re shielding your weld with which you’re implementing proper weld procedures/qualifications.

7. Welding power sources don’t cause porosity

It is really not uncommon to get a call from a customer who says “Hey, I’m getting porosity from your welder.” Plainly, welding power sources don’t cause porosity. We tell welders to recount their steps back from the point where the porosity began. Welders will usually discover that it began just when a gas cylinder was changed (loose connections, incorrect gas used), a new wire spool was put in, when someone didn’t prep the material properly (oxides found in the weld), or if the fabric was contaminated somewhere else over the line. More often than not the thing is due to an interruption or downside to the gas flow. Tracing back your steps will often lead dkmfgb the variable that caused the porosity.

Rise Steel consisted of subsidaries of Cangzhou Spiral Steel Pipe Factory, Hebei All Land Steel Pipe Factory, Hebei Yuancheng Steel Pipe Factory, Cangzhou Xinguang Thermal Insulation Pipe Factory .The company is located in Tianjin port, the largest comprehensive port and an important foreign trade port, engaging in the management of steel pipe production nearly 20 years.The company is a high-tech enterprise intigrated with independent production and sales business.We are committed to the concept of “innovation, technology and service”.

Rise Steel consisted of subsidaries of Cangzhou Spiral Steel Pipe Factory, Hebei All Land Steel Pipe Factory, Hebei Yuancheng Steel Pipe Factory, Cangzhou Xinguang Thermal Insulation Pipe Factory .The company is located in Tianjin port, the largest comprehensive port and an important foreign trade port, engaging in the management of steel pipe production nearly 20 years.The company is a high-tech enterprise intigrated with independent production and sales business.We are committed to the concept of “innovation, technology and service”.

Contact Us:
Address: APT. 1202 BLDG. B Kuang Shi Guo Ji Plaza, Tianjin Free Trading Testing Zone (Business Center), Tianjin, China.
Hamer Chen:[email protected]
Eason Gao: [email protected]
Miao lin: [email protected]
Amy Shi: [email protected]
Hamer Chen:+86 18202505824
Eason Gao: +86 18622403335
Miao lin: +86 13251845682
Amy Shi: +86 18630426996