Piping inspection services for API 570 process piping

These are planning ranges, not quotes. Pipe size, schedule, insulation and access decide the real price.

API 570 covers in service inspection, repair and rerating of metallic process piping. Owners classify each circuit by consequence of failure, from Class 1 for flammable or toxic service to Class 3 for low risk lines, and the class sets the visual, thickness and CUI inspection intervals. Thickness readings taken at CMLs give a corrosion rate and a remaining life, and the shorter of half the remaining life or the class limit sets the next date. The code is published by the American Petroleum Institute, and the inspector who signs the plan must hold API 570 certification. The same logic for tanks and vessels is on our storage tank and pressure vessel pages.

Thickness work is the base of most contracts, but the larger bills come from what surrounds it. Insulation has to be opened or removed to read the pipe. Elevated lines need scaffolding or rope access. Hot lines need cool down or a high temperature probe. Lines in hydrogen, caustic or amine service may add targeted checks such as PAUT for cracking. Ask the quote to separate NDT labour, access and insulation work, since access is often the larger share. For weld level testing on new work see pipe weld testing.

Refinery and chemical plant reliability engineers buy circuit campaigns before a turnaround. Power plant owners test steam and feedwater lines for flow accelerated corrosion. Food, beverage and pharma plants inspect process and utility piping for insurers. Oil and gas operators check pipework at processing sites, covered further on the oil and gas industry page. Maintenance planners buy it to defend an interval extension or to prove a repair did the job.

1. You send isometrics or a line list, with pipe size, schedule, material, service and last thickness readings.
2. The company proposes CML locations, methods and crew size, and flags insulation to open.
3. Technicians clean the spot, take UT readings or shoot profile radiographs and mark each location on the isometric.
4. A qualified inspector reviews the data, calculates corrosion rates and remaining life per circuit.
5. You receive a report with CML tables, rates, next inspection dates and repair recommendations.

• Straight UT thickness on a small circuit, 20 to 60 CMLs. $800 to $2,500.
• Large circuit with CUI checks and profile RT. $3,000 to $6,000.
• Weld RT on repaired piping. $60 to $250 per weld.
• Insulation removal and reinstall. $15 to $60 per linear foot.
• Scaffolding. Often $1,000 to $10,000 per area.
• Mobilization and travel. $500 to $3,000 per trip.

Night shifts, turnaround standby and rush reports add premiums. See NDT inspection cost for how crews price the underlying methods, and ultrasonic testing cost for UT rates.

Ask for UT technicians certified to ASNT Level II or higher and an API 570 inspector on the job. Request a sample report on a circuit like yours, check that CML numbers carry over from year to year and ask how they calibrate on your pipe material. See the ASNT pages for what technician levels mean, and confirm insurance and site safety records.