Pressure vessel inspector: what the job involves day to day

A day on site

Most days start with a plan. You review the vessel's history, the last inspection report and any open recommendations, then walk the equipment with that context in mind.

A typical inspection involves:

• External examination. Looking at the shell, heads, nozzles, supports, insulation and coatings for corrosion, leaks, distortion and mechanical damage. Saddles, skirts and low spots where water sits get extra attention.
• Internal examination. When a vessel is opened during an outage, you examine the inside surfaces, welds, internals and linings, often after confined-space preparation by the plant.
• Thickness readings. You take ultrasonic thickness measurements at set locations, compare them with earlier readings and calculate how fast the metal is thinning.
• Follow-up checks. Pressure relief devices, attachments and repairs are checked against the plan.

Before you leave the site, you confirm that findings needing quick attention reach the right person. A thin spot near a nozzle or a leaking flange is not something to save for the end-of-week report.

The rest of the day is paperwork that matters: photographs, sketches, readings and notes entered while the details are fresh.

For a printable version of that walk, use our pressure vessel inspection checklist.

Vessel types you will see

Variety is one of the job's real draws, because no two vessels age the same way. The word "vessel" covers a lot of equipment. Expect separators, drums, columns and towers, reactors, heat exchangers, air receivers and storage spheres. Each has its own wear patterns. A column may thin near the vapor outlet, a drum may corrode at its bottom, and an exchanger may have problems tied to its tube bundle. Heat exchangers, columns and drums each reward a different checklist, and a good inspector adjusts the plan before arriving on site. Pairing each vessel with its likely problems keeps your inspection plan focused. Learning those patterns is a large part of the job, and our damage mechanisms guide shows how common mechanisms tend to appear and how they are found.

What you document and who signs

The inspection report is the product. It records what was examined, how, what was found and what you recommend. Good reports include thickness trends, calculated corrosion rates, remaining life estimates and the next inspection date. They tell the plant what to repair, monitor or leave alone, and a clear report earns trust faster than anything else in this job.

Who signs depends on the employer and the jurisdiction. In many plants the certified inspector signs the findings and recommendations, while engineers decide on repairs or rerating. Your employer sets who may inspect which equipment, and your jurisdiction may add its own rules.

Tools of the trade

The tools are simple, and the skill is in using them well. You do not need a truck full of gear for most inspections. The core kit is:

• An ultrasonic thickness gauge and couplant
• A flashlight, inspection mirror and magnifier
• Calipers, pit gauges and a tape
• A camera and a notebook or tablet
• Personal protective equipment for the site

Keep the gear organized and calibrated, because a gauge that drifts or a camera with a dead battery costs you a return trip. Other methods, such as magnetic particle or liquid penetrant testing, are often done by examiners you direct. Knowing what each method can find helps you pick the right one.

Owner-user versus inspection company work

The job changes with the employer. Owner-user inspectors work at one plant, know its vessels in depth and manage a long inspection history. Inspection company inspectors travel to client sites, often for outages and turnarounds, and see a wider range of equipment and conditions. Both do the same core work: examine, measure, calculate, report and recommend. The difference is mostly in rhythm, travel and how long you live with the results of your own recommendations. The pressure vessel inspector salary guide explains how to compare base pay with total compensation across roles like these.

Where API 510 fits

API 510 is the certification many employers look for when hiring pressure vessel inspectors. The exam covers thickness calculations, welding procedure review, nondestructive examination and practical inspection knowledge, which is the same ground you cover on the job. Eligibility depends on education and documented vessel experience, and the requirements and cost guide walks through the routes and budget. If your equipment includes piping or tanks, the API 510 vs 570 vs 653 comparison shows which certification fits. Once you know the work suits you, see who hires and what postings ask for.

Next steps: see how to get pressure vessel inspector certification, what pressure vessel inspectors are paid and who is hiring.

If you want to see how your knowledge matches what the credential asks, the free 10-question check takes a few minutes, needs no signup and shows which areas to study first.

FAQ

What does an API 510 inspector inspect?

Pressure vessels that are in service, such as separators, drums, columns, reactors and heat exchangers. Inspectors examine them externally and internally, take thickness readings and judge whether they can keep running safely until the next inspection.

Is it a desk or field job?

Both. Field work is examination and readings, and desk work is calculations, report writing and planning. The mix depends on your employer, with contractor roles usually leaning toward field work and some owner-user roles leaning toward records and planning.

How is it different from a welding inspector?

A welding inspector focuses on welds during fabrication or repair, checking procedures, workmanship and acceptance. A pressure vessel inspector looks at whole in-service equipment over time, including damage, thinning and remaining life. Welding review is part of API 510, but it is one section of five.

Do I need an engineering degree?

Not necessarily. API's eligibility routes combine education with documented experience, and one route requires no formal education with five or more years of relevant vessel work. The requirements and cost guide lists all four routes.