Using welding codes to develop robust welding procedures

Welding codes, procedures, qualifications, and certifications—what are they, and how are they used? They can be confusing, at best. Worse still, some welding applications don’t need to comply with any sort of code, written procedure, or anything else. Getty Images

You run a fabrication shop, your shop’s work involves a lot of weldments, and your customers are depending on your welders to get the job done right. Your welders have a lot of knowledge, the experience pool in your shop is deep and wide, and you have certified welders, so what could go wrong?

Well, quite a bit. Understanding the roles of welding codes, procedures, qualifications, and certifications is the foundation. Purchasing the code, designating someone to become thoroughly familiar with it, and using it to develop the necessary welding procedures for every weldment your shop are three steps on the path to making sure the welds are done properly. At the same time, three separate people, or groups of people—those who helped develop the welding procedure, the welding staff, and the quality control department—have roles to play and contributions to make.

In addition to providing the foundation for the welding processes, adhering to the code is a critical step in mitigating risks. Your staff might be the most knowledgeable welders anywhere, and their welds might exceed all expectations, but proper documentation is necessary. If something goes wrong with a weldment your company made, you might need to explain how the welding procedure was developed, how it was tested, and how your staff was trained. If you haven’t documented these steps, you’ll be in a tough spot, but if your company has sufficient documentation to show that it makes welds to code, you’ll be in a good position to defend the integrity of your products.

Codes, Procedures, and Certifications

In many cases, an item that isn’t likely to support much weight or undergo much stress—say, a bracket for a small bookshelf or a gusset for a rack to hold some tools—doesn’t need a thoroughly engineered weld joint or a highly trained welding staff to make it. When the weld joint’s reliability is critical, however, you need to follow several steps to develop a reliable weldment. These include engineering the joint; developing a written procedure for making the joint; verifying that the weldment can withstand the expected stresses, including a safety factor; and testing the welders charged with making the joint.

This multifaceted task starts with engineering the weldment, which is the responsibility of the manufacturer. This can be a lengthy step that encompasses several stages:

• Determine the joint’s function—withstanding forces such as compression, tension, torsion, and shear.

• Calculate the needed strength.

• Design the joint’s configuration and dimensions.

• Research the strength and behavior of the materials to be welded.

• Determine preheating or postweld heat-treating requirements.

• Research related factors that contribute to the joint’s suitability for service.

The next step is to determine whether a welding code applies and, if so, to ensure that the design elements of the joint comply with that code.

Simply stated, a welding code is a written standard for industry that describes a large number of welding scenarios and specifies the factors that go into making an acceptable weld for each one. For example, if you need to make a structural element from steel for a cab for a bulldozer, the American Welding Society (AWS) publishes code D14.3/D14.3M:2010 AMD1, Specification for Welding Earthmoving, Construction and Agricultural Equipment, which covers welding that cab frame. If your weldment is a fillet weld made horizontally on 5/16-in.-thick steel using gas metal arc welding (GMAW), you can find the requirements for the procedure for making that weld—acceptable filler metal type and diameter range, proper welding current, and so on—in that standard.

This sounds straightforward, but it’s not quite that simple. Dozens of codes are available from a handful of standards-setting groups, so finding the right code is critical. Regarding structural applications alone, AWS publishes several codes, such as D1.1/D1.1M:2015, which covers welding of structural steel. It publishes individual D1-series codes for several other materials, such as aluminum, sheet steel, stainless steel, and titanium. Regarding industrial machines and other equipment, it publishes:

• D14.1/D14.1M:2005-AMD1, Specifi-cation for Welding of Mill Cranes and Other Material Handling Equipment.

• D14.5/D14.5M:2009, Specification for Welding of Presses and Press Components.

• D14.6/D14.6M:2012, Specification for Welding of Rotating Elements of Equipment.

• D14.7/D14.7M:2005, Recommended Practices for Surfacing and Reconditioning of Industrial Mill Rolls.

• D14.9/D14.9M:2013, Specification for the Welding of Hydraulic Cylinders.

• D15.1/D15.1M:2019, Welding Specifi-cation for Railroad Cars and Locomotives.

After refining the specific steps for making your weldment with the information derived from the welding code, you have a welding procedure specification (WPS). Nobody would expect a welder to drag a $500 welding code out to the shop floor and page through it, looking for guidance in making each weld, so codes require that you develop your own WPS, which is a detailed set of instructions for the welders to follow.

This also sounds straightforward, but the devil is in the details. Welding codes are lengthy, so the challenge in writing a solid WPS is identifying what to include and what to exclude. Furthermore, writing a WPS isn’t enough. You have to qualify the WPS by following its steps to make a test weld, and then subject that test weld coupon to bend tests and tension tests to determine the weld’s ductility and strength. Other tests, such as a Charpy impact test, also may be warranted to determine the material’s toughness after welding. Once you have demonstrated that the WPS is successful, you document it in a procedure qualification record (PQR).

The fourth component is welder certification. Small companies often rely on third parties (certifying agencies or technical schools) for this, whereas an employer with more means can certify its own welders. In any case, certification is the responsibility of the welder’s employer.

A welder who is to weld in compliance with AWS D1.1 makes a test weld or welds that comply with AWS D1.1, and if successful, he can be certified as qualified to AWS D1.1. To maintain certification, the welder must make welds using each process at least once every six months, and a supervisor must document that he or she did so. The certification usually is indefinite.

Maintaining and updating the documentation, paperwork that shows every t has been crossed and every i has been dotted, is the fourth step. Codes, WPSs, PQRs, and certifications all contribute to making good welds and therefore good products; you must document them.

To summarize, the code is for the entire industry; a WPS is specific to a weldment that a manufacturer uses to make a specific assembly; a PQR documents that the WPS is satisfactory; and certification shows that a welder has passed a test regarding a code.

Note that AWS sells a couple of dozen standard WPSs for welding common materials such as carbon and 300 series stainless steel, so developing a WPS from scratch isn’t always necessary.

Code or No Code? In some cases, welding in accordance with a code is mandated by law; in others, it can be stipulated by contract; otherwise, it is voluntary. Because some welds require code compliance and others don’t, fabrication shop owners often simply aren’t aware that they need to purchase a welding code or two.

“In many cases, companies that should be using the code aren’t doing so,” said Paul Cameron, a certified welding inspector (CWI). “Often a company doesn’t own a copy of the code and doesn’t know that having one is a requirement.”

If they’re not using a welding code, what are they using? Company executives and shop supervisors have a million things to do, so if they have skilled welders on staff, and the welders have a couple of decades of welding experience, the entire burden for compliance might rest on those welders’ shoulders, Cameron said.

Walter Sperko, a professional engineer and welding specialist, concurred. “Many manufacturers rely on shop practices,” he said. These aren’t necessarily best practices or even modern practices. “In some cases, they get passed down from one generation to another.”

Regardless of the welders’ knowledge base, if they make good welds and the customers have no complaints, it’s not clear that a problem exists. Problems that don’t seem to exist don’t seem to need solutions, or in common parlance, “If it ain’t broke, don’t fix it.”

Indeed, it’s not broken until something breaks. When a fire truck can’t respond to a call or trailer falls apart at highway speed, and the failure is due to a bad weld that can be traced back to your shop, it’s too late to order a code, develop a WPS, establish a PQR, and qualify your staff.

Beware of the Limitations. Non-welders on the management staff need to be aware that while buying a code is a necessary first step, getting the right code for the application is critical. For example, the American Society of Mechanical Engineers Boiler and Pressure Vessel Code covers all aspects of designing, building, and repairing boilers, pressure vessels and nuclear components, and it comes in 12 sections. A shop that does repairs doesn’t need to buy every section.

For many other welding applications, care is necessary in getting the right code. Making a weldment for a structural application is a good example. A code that seems to have an extremely broad purpose, AWS D1.1/D1.1M:2020 Structural Welding Code – Steel, doesn’t cover every structural steel application.

“It applies only to steel greater than 1/8 in. thick and less than 100,000 pounds per square inch minimum yield strength,” said Cameron. “Also, it applies only to carbon steel.” AWS publishes a separate code for stainless steel structural applications (not to mention codes for other metals, such as aluminum and titanium), codes for two specific products for structural applications (sheet and reinforcing bars), and even a code that describes specific considerations for seismic activity.

Likewise, passing a test to achieve a certification is limited. A certification doesn’t mean a welder is proficient using any welding process in the corresponding code; it means he passed a test on one welding process relevant to the code.

“Certification is based on a very specific test,” Cameron said. “It calls for a specific material, electrode, electrode diameter, and process,” he said. “Passing a test to use flux-cored arc welding in the horizontal position doesn’t qualify that welder to use GMAW overhead, even if the other parameters are the same,” he said.

In some cases, a certification does allow some latitude. For example, a welder who needs to perform a specific weld process on several thicknesses of material doesn’t necessarily have to pass a test on every thickness.

“In many cases, a standards developer like AWS uses the 2T guideline,” Sperko said. “A welder who makes a test weld using a specific process on some thickness, T, is qualified to weld up to twice that thickness, or 2T,” he said. “Furthermore, if a welder is certified to weld on 1-in.-thick material with a process, often the range he’s allowed to weld is unlimited.”

Similarly, two codes often have enough latitude that both can apply to one application. When making a cab for an earth-moving machine, AWS D14.3/D14.3M:2010 AMD1, Specification for Welding Earthmoving, Construction and Agricultural Equipment, is the obvious choice, but the more general AWS D1.1/D1.1M:2020, Structural Welding Code – Steel, is also acceptable. It’s a matter of the OEM’s preference, but the OEM needs to pick a code then follow it.

Who’s Involved? As in the case of a certified welder, a CWI has met specific requirements that may be required by a code. The educational requirements run the gamut, from less than an 8th grade education to a bachelor’s degree in welding engineering or welding technology. The corresponding minimum amount of welding experience needed also is broad, varying from 12 years to one year, respectively. The requirements for certified associate welding inspector are not as stringent; those for senior certified welding inspector are higher and include six years’ tenure as a CWI during the previous eight years.

Depending on the size of your company and its goals relative to its welding capabilities, you might be interested in seeking out some specialists for your staff or a consultant, such as a certified welding educator, welding engineer, certified welding supervisor, certified radiographic interpreter, and certified robotic arc welding operator and technician. It might be beneficial to get some assistance from a consultant with a background in metallurgy, mechanical engineering, or civil engineering.

Certainly each has something to offer. A welder who spends eight hours a day reading weld pools—and who spends an hour a day grumbling because he doesn’t have enough clearance for some of the weldments—can provide great feedback for putting a new weld procedure through a few practical trials. Folks who know the codes forward and backward can help with compliance, and a metallurgist or an engineer can help you determine strength and durability—evaluating the heat-affected zone and identifying the necessary destructive tests and hardness tests to evaluate welds made to the WPS.

A key duty that doesn’t correspond to a certification is writing a WPS. It requires no specific background or welding experience. This means anyone can develop a WPS, whether drawing on education, hours spent reading welding codes and perhaps other welding-related literature, or welding experience. Some might see this is a drawback, but regardless of that person’s credentials, the proof is in welding a test coupon and documenting it and the test results on a PQR.

In other words, either the weld is found to be adequate or it’s not, and either the WPS is accepted or it’s not, and either the WPS is accompanied by a PQR or it’s not. That said, it’s certain that a wide-ranging accumulation of welding knowledge and experience contributes to writing a more thorough and robust WPS.

Putting the Codes to Use

Employers must provide their welders the necessary knowledge to get the job done, which often means much more than buying the product-relevant code, Cameron said.

First, you probably need three codes—the welding code specific to your application, plus two more:

• AWS A2.4, Standard Symbols for Welding, Brazing, and NonDestructive Examination

• AWS A3.0, Standard Welding Terms and Definitions

Second, every welder in the shop needs to become proficient in the welding symbols and terms used by their shop. Nearly everyone in every industry uses some level of shop-speak, so it’s necessary to get everyone onto the same page regarding standard terminology.

Third, someone—ideally, someone knowledgeable in welding engineering and metallurgy—needs to become familiar enough with the code to establish WPSs or help establish them. This person or small team must go through the selected code thoroughly enough to understand the content, determine how the content applies to the welds made in your shop, and identify a WPS for every weldment. Two key points here are attention to detail and strict adherence to the code.

“It’s necessary take the code literally,” Cameron said. “Every and, every or, and every shall are there for a reason.”

Finally, it’s the employer’s responsibility to go beyond English, if necessary. A 2015 report from the U.S. Census Bureau identified 350 unique languages spoken in the U.S. (at least 192 in New York City alone). It’s up to the workers to do the job, but the employer must give them the tools to do so. As a practical matter, this might mean designating the shop folks who are proficient in two languages to assist those who aren’t. A thorough resolution would be to have the WPS translated by a technical writer proficient in both languages. However, written documentation in languages other than English isn’t a requirement; it is perfectly acceptable for a shop supervisor to provide verbal instructions based on the WPS requirements.

Making a Case for Due Diligence and Managing Risks

If a weldment on a piece of machinery fails, an investigation is bound to ensue to determine just how the weld failed. The weld may have been perfectly sound when it was made, and some other cause for the failure may have been at fault. Perhaps improper protection allowed corrosion to set in, weakening the weld. Maybe the system or machine was misused or even abused, putting much more stress on the weld than it was designed to handle. Other scenarios are possible, but nevertheless, you might find yourself answering a lot of questions about your shop’s practices and weld integrity. Proper documentation is necessary when questions of culpability arise.

For cases in which a welding code isn’t required by a legal jurisdiction or by contract, following a code and performing weld inspections contribute to due diligence. Sperko cited the 2012 court case of James Lomma and his company, New York Crane and Equipment Corp., as a cautionary tale concerning a weld failure. One of the company’s cranes was taken out of service for a repair; on the day the crane was put back into service, it collapsed, killing two people.

In a criminal suit, the prosecution alleged that Lomma and New York Crane focused on the cost and speed, rather than the integrity, of the repair. Regarding the entire responsibility—repair and inspection—it’s possible that the waters were muddied in that New York City’s Department of Buildings is responsible any post-repair inspections. In 2010 the city’s chief crane inspector, James Delayo, was convicted of taking bribes and falsifying crane inspections, which may have contributed to Lomma’s acquittal.

Although tube or pipe fabricators aren’t likely to get involved in anything as significant as repairing a construction crane, the lesson is clear: Due diligence and thorough recordkeeping are essential.

Sperko’s advice is to take charge of the subassemblies and assemblies that leave your company’s premises, relying on your own processes rather than those of your customer. If you’re making critical welds, due diligence, starting with the relevant welding code, might prevent a weld failure, avert an injury, save a life, and keep your company’s reputation intact.