Weld inspectors, especially those new to the trade, put a lot of emphasis on the equipment needed to do the job: flashlight, mirror, high-low gauge, pit gauge, bridge camera, and a borescope. However, this isn’t the entire toolkit. A welding inspector must also know the applicable codes, learn about the project owners’ specifications, and carry a personal logbook to make notes about conversations and inspections.
The quality control profession is far from static. The need for quality control inspectors is increasing, and the field is growing. New job opportunities are created as rising numbers of owner-users, manufacturers, and contractors learn that well-trained and knowledgeable quality control inspectors impact the quality of a facility or project.
Anyone interested in becoming an inspector should familiarize himself with the necessary tools. Merriam-Webster defines a tool as “Something (as an instrument or apparatus) used in operating or necessary in the practice of a vocation or profession.”
When you ask people in the construction industry about inspection tools, common answers are a flashlight, mirror, high-low gauge, pit gauge, bridge cam, and borescope. However, often they leave out the most essential and critical tools: codes, owner specifications, drawings, bills of material, and a personal logbook.
As any welding inspector knows, having a good flashlight is essential when looking through a window left in an open butt joint to examine the internal of a root bead. Also, when used properly, a flashlight can help spot an undercut at the toe of a weld. Likewise, a mirror is handy for a visual inspection of the internal bead of a pipe weld, test coupon, and any weld near an obstruction that prevents a direct view.
A pit gauge or a bridge cam is handy for measuring pits in the wall of base material, undercut, or the amount of reinforcement of a weld, whether it’s convex or concave. In addition, as borescopes become more affordable and smaller in size, they are being used more frequently to do visual inspections where it is impractical or impossible to see with a mirror and a light.
These tools are helpful, but their usefulness is limited if the inspector isn’t familiar with the codes, specifications, and bill of materials.
Critical Tools
The most important tools are not physical tools but documentation and knowledge. The relevant documents provide recommended and required construction practices, describe the correct use of inspection instruments, and offer acceptance criteria for an inspector. Others are the construction codes and the owner’s specifications.
Codes. Welds are engineered to meet various criteria depending on expected service life, environment, temperature, strength, and system cleanability. These are determined through codes written by entities such as the American Society of Mechanical Engineers (ASME), the American Welding Society (AWS), and the American Petroleum Institute (API). Therefore, a welding inspector must have a good understanding and working knowledge of these codes.
Most projects must meet several codes and national standards. For example, a pharmaceutical plant may use ASME Biopharmaceutical Equipment Standard ASME B31.1, ASME B31.3, ASME Sec. I, Sec. V, Sec. VIII, Sec, IX; and AWS D1.1.
The inspector does not need to have all these codes memorized but must have a working knowledge of each of them, focusing on details about acceptable procedures for preparation, welding conditions, and acceptance criteria.
Owner’s Specifications. An owner-user often has more stringent specifications than or supplementary to commonly accepted construction codes. Inspectors must read the owner’s specifications, including engineering drawings and bills of material. This is critical to ensure all job-, company-and site-specific needs are met. A copy of all specifications must be readily available to the inspector. It is a good practice for the inspector to note the owner’s specifications.
Personal Log. An inspector’s typical day is busy and involves examining weld parameters—weld joint fit-up, internal root beads, final welds, and hydrostatic test results, to name a few—and having many conversations. Therefore, the inspector should make comprehensive notes in a personal log to keep the details straight for future reference. In addition, such a log can be invaluable for future reference, mainly if a dispute arises.
An Ounce of Prevention
Inspectors aren’t the only ones who need to be familiar with codes, specifications, and standards. Everyone involved in the project should know the codes that apply to the job, which ultimately prevents rejects and rework.
The cost of rework is summarized in this equation:
(Hc x 3) + (Co x 2) + (Mo x 3) + (T x 2) + (Ma x 2) + (Lt x 1) = C
Where:
Hc = Labor-hours of original work converted to cost
Co = Consumables for original work (e.g., electrodes and shielding gas)
Mo = Mobilization from ongoing work to rework
T = Required nondestructive examination of repair, including visual inspection
Ma = Material for original work and new material for rework
Lt = Lost schedule time in labor hours, converted to cost
C = Total cost of repair or rework
Preventing rework is critical to keeping projects on budget and schedule.