A coded welder is a welder who has passed a welder approval test to prove they can weld to a particular specification. In simple terms, it means they have shown, through testing, that they can make high quality welds that meet welding codes and industry standards. This matters because coded welds are often used in safety critical applications where a failure could cause serious harm. C
Coded welders usually work in areas like construction, fabrication, and heavy industry, where the finished welds must meet strict standards for quality and safety. You might find them working on site with a team, or in a workshop making products that must meet a set level of reliability.
What is a coded welder?
A coded welder is a qualified welder who has passed approval tests for a specific welding setup. The test is not only about making a weld that looks neat. It is about proving the weld will perform properly in real work, often under pressure, heat, vibration, or load. That is why coded welding is linked to critical applications such as pressure vessels, pressure pipework, pipelines, and structural steel.
The idea of “coded” is based on welding code requirements. A welding code is a written set of rules that explains what is required, how the work should be done, and how it should be checked. Coded welders need the skills, practice, and knowledge to follow these rules closely, because the job commonly requires work that must be inspected and recorded.
Coded welders and certified welders: what is the difference?
People often mix up coded welders and certified welders, and the terms can sound very similar. A certified welder is a welder who has completed training and has passed tests that show they can weld in a certain way, using a certain welding process. This might include MIG welding, TIG welding, or arc welding, and it may be based on the materials they are tested on.
A coded welder goes further because the welder approval is tied to a code, a welding procedure, and a specific welding configuration. That means the approval is not just “I can weld”. It is “I can weld this type of joint, in this position, on this material, using this welding process, to this standard”. This is the key difference between general certification and welder coding for real jobs with strict requirements.
You may also see the phrase “coded welders and certified” used together. That is because many coded welders are also certified welders, but not all certified welders hold current coding for the exact work a job may require.
Why coded welding is used for critical work
Coded welding is commonly used when a mistake could cause a leak, a collapse, or a dangerous failure. This is why coded welders are often required for pressure vessel work, pressure pipework, and some parts of structural steel fabrication. In these jobs, welds may be checked by inspection and testing, and the work must meet a particular specification.
For employers, using coded welders helps ensure the work meets industry standards. For welders, being coded can open up more job options in the UK and across the wider industry. It can also show that a welder has developed strong skills and knowledge over years of work and practice.
What happens in a welder approval test?
A welder approval test is a practical test where the welder must complete welds to a set of rules. The test may be called an approval test, a welder approval test, or a welding approval, depending on the company and the standard being used. The test is often completed under controlled conditions, with clear instructions that cover the welding methods, the welding procedure, and the required quality level.
Many tests are job-based. A welder might need to pass a test in a specific position, or a test in a specific welding configuration that matches the work they will do on site. For example, a pipe welder may need a different approval from someone working on plate. A welder might also be tested on different materials, such as mild steel or stainless steel, because codes often limit what the welder is approved to weld.
How welds are tested after the welding is done
After a welder completes the test piece, the weld is checked. This is done to ensure the weld meets the standard and the particular specification. Testing can include a close visual check for surface faults, and it can also include more detailed tests to find problems inside the welds.
Some approval tests use bend tests or fracture tests on cut samples. Others may use inspection methods that look inside the weld without cutting it, depending on what the code requires. The point is to show the welder can consistently perform work that meets the required quality, not just one good weld on a lucky day.
Common welding codes and industry standards
Welding codes set out what must be done and how it must be proved. In the UK, you will often hear about BS and BS EN ISO standards. BS 4872 is commonly used for some types of welding work, and BS EN ISO 9606 is widely used for welder qualification in many industries. You may also see BS EN ISO written as “bs en iso”, and you will often see “ISO” mentioned because it links to international standards.
There are also international standards used in many projects. For example, ASME IX, sometimes written as “asme ix”, is commonly used for pressure vessels and some pipework. ASME comes from the American Society of Mechanical Engineers, and you may also see references to the society of mechanical engineers. In construction and structural work, codes from the American Welding Society may appear, such as AWS D1.1, and sometimes AWS D1.1 D1.2 D1.6, depending on the type of work and materials.
Standards can be described in different ways, such as a european standard, a british standard european approach, or a european british standard, depending on how the rules are published and used in contracts. ISO is linked to the International Standards Organisation, which helps set common rules used around the world.
Welding procedures and why they matter
A coded welder does not just “do their own thing”. They are expected to follow welding procedures, including a welding procedure that matches the job requirements. A procedure will cover details such as the welding process, the type of welding, heat settings, filler materials, joint preparation, and the order of work.
This matters because two welders can produce very different results if they use different methods. Following welding procedures helps ensure the weld is consistent, safe, and suitable for the products being made. It also supports quality and safety checks, especially when a job must meet strict codes.
Types of welding and what coded welders may be approved for
There are many types of welding, and a coded welder is not always approved for every type. Approval is normally linked to a welding process and the way it is used. MIG welding is common in fabrication because it is fast and effective for many jobs. TIG welding is often used where a cleaner finish and tighter control are needed. Arc welding is also widely used and can be suitable for many site conditions.
The type of welding, the position, and the material all affect what the welder approval covers. This is why employers often ask for proof of the exact approvals required, rather than relying on a general statement that someone is a certified welder.
Keeping approval current
Welder approval is not always for life. Many codes require welders to show they are still active and still able to meet the standard. This could mean doing regular work that is recorded, taking repeat tests, or completing checks over time. If a welder stops doing that type of work for too long, they may need to re-test.
This is another reason coded welders are valued. They can demonstrate that they have passed practical tests, kept their qualifications up to date, and continued to meet the required level in real work.
Skills and knowledge that matter most
A coded welder needs good hands-on skills, but they also need theoretical knowledge. They must understand drawings, specifications, and code rules, and they need to know how different materials behave during welding. They must also understand how heat can affect strength and shape, and why certain welding methods are chosen for certain jobs.
Just as important is the ability to work safely and reliably. Many coded welding jobs are carried out on site, sometimes in tight spaces or awkward positions. Being able to perform under pressure, follow instructions, and work well in a team is part of what employers look for.
Safety on site and in the workshop
Safety is a big part of coded welding. Welders work with heat, bright light, fumes, gas, and heavy equipment. Good safety habits protect the welder and everyone around them. This includes wearing the right protective gear, keeping the work area tidy, and following site rules.
Quality is also linked to safety. A weld that fails can put people at risk, especially in pressure vessels, pressure pipework, and construction work. This is why coded welders are required to meet strict standards and why their welds are commonly tested.
Safety on site and in the workshop
The five basic types of welding joints Welding joints are where two pieces of metal meet and are welded together. These joint types are commonly used across the industry, and coded welders may be tested on one or more of them depending on the job.
A butt joint : A butt joint is where two pieces meet in the same flat line. This joint is often used for pipes and plate work because it can provide a strong, clean join when done correctly.
A lap joint : A lap joint is where one piece overlaps another. It is often used in sheet work and some fabrication tasks where extra contact area is helpful.
A tee joint : A tee joint forms a “T” shape where one piece meets the middle of another. It is common in frames and structural parts, where strength is needed at the meeting point.
A corner joint : A corner joint is where two pieces meet at a right angle to form an “L” shape. This is common in box sections, frames, and general fabrication.
An edge joint : An edge joint is where the edges of two parts sit side by side and are welded along the edge. This is often used with thinner materials and certain sheet metal jobs.
Rights, responsibilities, and what employers expect
A coded welder has rights at work, including the right to a safe workplace and clear instructions. They also have responsibilities, such as following safety rules, using equipment correctly, and producing welds that meet the specification. Employers expect coded welders to take care, avoid shortcuts, and report problems early.
In many workplaces, coded welders may also support others by sharing good practice and helping to keep quality high across the team. That helps the whole job run smoothly and helps ensure the finished work meets the required standard.
Contact A Coded Welder Service
If you need welding services for a project, or you want to find out what approvals are required for a job, contact us at Anderson Engineering And Welding Services. If you would like to discuss coded welders, welder approval, or the right welding codes for your work, get in touch and we can help you understand what is required.
Anderson Engineering and Welding Services offers expert fabrication and coded pipe welding solutions in Manchester, , and the North West. With over 80 years of combined experience, we deliver high-quality results for residential, commercial, and industrial projects.
Coded Pipe Welding In Manchester
