Boiler inspection services for NBIC and ASME power boilers

These are planning ranges, not quotes. Boiler size, fuel, tube count, access and the report you need change the real price, and a full outage campaign costs less per tube than a call out for one failed tube.

Power boilers are built to ASME Section I and heating boilers to Section IV. In service inspection, repair and alteration follow the National Board Inspection Code, which the National Board of Boiler and Pressure Vessel Inspectors publishes and most states adopt. Most jurisdictions require a certificate inspection of power boilers every year, done by a commissioned inspector from the state or from your insurer, and often every two years for low pressure heating boilers. Exact intervals and exemptions differ by state, so confirm yours with the jurisdiction. NDT is usually the extra work that answers a specific question for that inspector, such as how much wall is left on the waterwall tubes or whether a drum weld has cracked. For the underlying method see ultrasonic testing services, and for process vessels attached to the same plant see pressure vessel inspection services.

Boiler tube leaks are the leading cause of forced outages in many plants, and they usually come from damage that was measurable months earlier. Fireside corrosion and erosion thin tubes from the outside, waterside deposits cause underdeposit corrosion and overheating, and thermal fatigue cracks the welds where tubes meet headers. A UT thickness grid or an EMAT scan gives you a map of remaining wall per tube, so you can replace the worst 5 percent at the next outage instead of the whole panel after a failure. Repeat the same grid points each year and the corrosion rate falls out of the data. A borescope pushed into headers and drums shows deposits and cracking that no outside method sees, see borescope inspection for how that works.

Plant engineers in food, paper, chemical, hospital and university plants buy annual boiler NDT to support the jurisdiction inspector and the insurer. Power producers and cogeneration operators schedule tube thickness and weld programs around planned outages. Waste to energy and biomass plants, where fireside corrosion is severe, order tube mapping every year. Boiler repair contractors and fabricators order MT, PT and radiography on repair welds before the inspector signs the repair report. Our power plant inspection page covers turbines, switchgear and wind assets in the same plant.

1. You send boiler type, pressure, fuel, year built, tube material, the last inspector report and any known leaks.
2. The inspection company proposes a plan: which tubes and welds, which methods, crew size and access. Internal work needs the boiler cooled, drained, locked out and cleaned of loose scale.
3. Crews mobilize, complete site safety steps and inspect in the agreed outage window. Boiler drums and furnaces are confined spaces, so a permit, an attendant and a rescue plan are required.
4. Data is reviewed by a qualified technician and the inspector, who flags tubes for replacement and welds for repair.
5. You receive a report with thickness maps, weld results, a defect list, corrosion rates and recommended repairs. Urgent findings are called in the same day.

Cleaning, scaffolding and downtime often cost more than the inspection itself. Ask whether the quote includes them.

• UT thickness or EMAT scan of waterwall tubes. $1,500 to $15,000 depending on tube count and access.
• MT of drum and header welds. $1,500 to $8,000 with surface preparation.
• PAUT or TOFD of thick drum seams. $1,500 to $6,000 per seam set.
• Borescope of headers and drums. $600 to $3,500.
• Radiography of repair welds. $60 to $250 per weld in the field.
• Mobilization and travel. $500 to $3,000 per trip for remote plants.

Standby during permits, night shifts and rush reports add to these numbers. Ask each contractor to list them separately so quotes compare like for like. Our NDT inspection cost guide shows how crews price the underlying methods.

Check that technicians hold ASNT SNT-TC-1A or CP-189 Level II certification in the methods quoted, and that the company has boiler specific experience such as waterwall mapping or EMAT. Ask for a sample report on a boiler like yours and how they reference tube locations so next year's scan lines up. Confirm the confined space program, injury record and insurance, and how quickly first data is delivered after the crew leaves site. Compare quotes on the same tube count and report format, not on the headline number.