Welding Coupon

What is a Welding Coupon?

Welding is an essential skill for many industrial jobs, and it’s important for welders to show their proficiency with the craft.

Most certifications require welders to demonstrate their skill by passing a welding coupon test according to code and standards.

Welding coupons are small pieces of metal (in pipe or plate form) used to assess welders’ skills through visual inspection, destructive testing, and other methods.

They allow welding professionals to determine and demonstrate the welder’s ability whether or not a welder is able to deposit a good quality weld joint.

In this article, we’ll be looking at the different types of welding coupons that are available and how they can be used in various welding test qualifications.

Types of Welding Coupons

ASME Section IX and AWS D1.1 have specific requirements for plate and pipe welding coupons for:

  1. Welding Procedure Specification Qualification (PQR),
  2. Welder Performance Qualification (WQT).
Image: Linkedin

Further based on the geometry, AWS D1.1 specifies the welding coupon in two types:

  1. Tubular &
  2. Non-Tubular

ASME Section IX also defines two types of welding test coupons:

  1. Plate Coupons,
  2. Pipe Coupons.

Both plate and pipe welding coupons must meet specific requirements, including size, thickness, joint preparation, and welding technique, as defined in ASME Section IX or AWS D1.1.

Plate welding coupons are used to test the welder’s ability to make a high-quality weld on a flat surface in different welding positions such as 1G, 2G, 3G and 4G.

Pipe welding coupons are used to test the welder’s ability to make a high-quality weld on a cylindrical surface.

Related reading: Pipe Welding Positions for welder Qualification.

Welding coupon dimensions

A welding coupon is a small piece of metal that is used as a sample in welding tests and evaluations.

The dimensions of the coupon are crucial in ensuring accurate results and determining the quality of the weld.

The coupon size should match the thickness and type of metal used in the actual welding, allowing for a fair assessment of the welding process.

The coupon dimensions also play a crucial role in determining the appropriate parameters for welding, such as welding speed, heat input, as well as providing sufficient materials for mechanical testing and NDT.

Welding coupon dimensions as per AWS D1.1 for WPS qualification

According to AWS D1.1, the following are the minimum dimensions for welding coupons used in the qualification of a Welding Procedure Specification (WPS):

  1. Plate Coupons:
    • Minimum length: 15 inches (381 mm), as per Figure 6.6 when CVN is not required. 21 inches (533 mm), when Charpy V-Notch (CVN) impact test is required.
    • Minimum width: 14-inches
    • Minimum thickness: Based on the thickness range of the production welds.
Groove weld test coupon example

Image Credit: CWB

Welding coupon dimensions as per ASME Section IX for WPS-PQR

As per ASME Section IX, the dimensions of the groove weld test coupon is a non-essential variable.

Hence, the size of coupon can be carried although it must be sufficient to provide material for testing.

Welding coupon dimensions as per ASME Section IX for WQT

  1. Plate welding coupon: The coupon should have a minimum length of 6 inches (150mm) as specified in QW 302.
  2. Pipe welding coupon: The coupon should have a minimum length of 6 inches (150mm) and shall include full weld circumference. For small diameter pipe, there can be multiple test coupons.
Welder Qualification Test WQT-Pipe
A pipe welding Coupon Example

The images displayed are of metal specimens utilized in a welder’s performance evaluation.

These specimens, referred to as “coupons,” underwent a destructive test by cutting out portions and reassembling the pieces after examination.

To gain certification for the welding process, the welder had to fulfill a set of assessment standards (E.g., AWS D1.1, ASME Section IX, ISO 15614-1).

What is a Welding Certification?

A Welding Certification is a formal recognition of a welder’s qualifications and ability to perform welding tasks to a specified standard.

The certification is usually granted by a governing body or an industry organization after the welder has successfully completed a practical test, that evaluate their knowledge, skills, and experience in welding.

The certification is an assurance to potential employers and clients that the welder is competent and capable of producing quality welds that meet the required specifications and standards.

The certificate is usually valid for a specified period, after which the welder must recertify to maintain their qualification.

Why we need Welding Test Coupon?

Welding test coupons are needed to ensure that the welder has the required skills and knowledge to produce high-quality welds and that the welding process is safe and reliable.

Here are some of the reasons why welding test coupons are important:

  • Welding qualification: Welding test coupons help to demonstrate the welding capabilities of a welder and are used to qualify and certify welders.
  • Welding procedure validation: Welding test coupons are used to validate the welding procedure and ensure that it meets industry standards and specifications.
  • Quality control: Welding test coupons help to identify potential issues and ensure that the welding process is producing high-quality welds.
  • Safety assurance: Welding test coupons help to identify any defects or anomalies in the welds, which can help to prevent safety issues and ensure that the welded components are safe for use.
  • Regulatory compliance: Welding test coupons are often required by regulatory bodies and industry standards to demonstrate that the welding process meets certain criteria for quality, safety, and reliability.

FAQS

What is a welding test coupon?

A welding test coupon is a small piece of metal used for welding qualification and certification purposes. It is used to demonstrate the welding capabilities of a welder and the quality of the welding procedure.

Why are welding test coupons necessary?

Welding test coupons are necessary to ensure that the welder has the required skills and knowledge to produce high-quality welds. They also help to validate the welding procedure, identify potential issues, and ensure that the welding process is safe and reliable.

What materials are used for welding test coupons?

The materials used for welding test coupons depend on the type of welding process and the intended use of the welded component. Common materials include mild steel, stainless steel, aluminum, and copper.

How are welding test coupons prepared for testing?

Welding test coupons are typically cut from the same material as the component being welded and prepared with similar dimensions, thickness, and surface finish. They are then welded using the same welding process, parameters, and techniques as the component.

How are welding test coupons tested?

Welding test coupons are tested using various nondestructive testing (NDT) methods such as visual inspection, ultrasonic testing, magnetic particle testing, and radiographic testing. The results of these tests are used to evaluate the quality of the weld and determine if the welder and welding procedure are qualified.

Material Welding is run by highly experienced welding engineers, welding trainers & ASNT NDT Level III bloggers. We strive to provide most accurate and practical knowledge in welding, metallurgy, NDT and Engineering domains.