Pressure vessels, process piping and storage tanks lose wall, crack and degrade while they operate. API in-service inspection assesses the condition of equipment that is already running, and establishes whether it remains fit for continued service and when it should be inspected next.
- Covers
- Pressure vessels, process piping, and aboveground storage tanks; inspection intervals, remaining life, and repair or alteration review
- Typical use
- Refineries, chemical and petrochemical plants, terminals and tank farms, midstream facilities
What API inspection covers
The three API inspection codes
- API 510, the Pressure Vessel Inspection Code, for in-service inspection, repair, alteration and rerating of pressure vessels
- API 570, the Piping Inspection Code, for in-service inspection, repair, alteration and rerating of process piping
- API 653, for inspection, repair, alteration and reconstruction of aboveground storage tanks
What the inspection includes
- Inspection planning around the damage mechanisms the equipment is exposed to
- External and internal visual inspection
- Thickness measurement, corrosion rates and remaining life
- Supporting NDT, such as UT, MT, PT or RT, where a damage mechanism calls for it
- Inspection intervals for the next internal, external and thickness inspections
- Review of repairs and alterations
- Reports and records that support the owner’s inspection program
Where it’s used
- Refineries
- Chemical and petrochemical plants
- Terminals and tank farms
- Midstream facilities
- Any plant that runs pressure vessels, process piping or aboveground storage tanks
Codes and standards
- API 510, API 570 and API 653, as above
- API RP 572, RP 574 and RP 575, the recommended practices for inspecting pressure vessels, piping components and storage tanks
- API RP 571, damage mechanisms affecting fixed equipment in the refining industry
- The construction codes the equipment was built to, such as ASME Section VIII, ASME B31.3 and API 650
- The owner’s inspection program and any jurisdictional requirements
Who does the work
The API codes require the inspector of record to hold API’s individual certification for the code concerned: API 510 for pressure vessels, API 570 for piping and API 653 for aboveground storage tanks. We match the inspector to the code.
The NDT that supports an API inspection is performed by technicians certified in each method under a written practice that follows SNT-TC-1A, or NAS410 for aerospace and defense work, with a Responsible Level III overseeing the program.
Training
API certifies its inspectors through its own examinations. Midgard trains technicians in the NDT methods that support in-service inspection, including ultrasonic and thickness testing, magnetic particle, penetrant, radiographic and visual testing, at Level I, II and III, with examinations at your facility or ours. See training and certification.
Common questions
What is the difference between API 510, API 570 and API 653?
They cover different equipment. API 510 is for pressure vessels, API 570 for process piping, and API 653 for aboveground storage tanks. Each sets out how that equipment is inspected in service, how intervals are set, and how repairs and alterations are handled.
How often does equipment need API inspection?
Each code sets maximum intervals and ties the actual interval to the corrosion rate and remaining life of the equipment, so equipment losing wall quickly is inspected more often. Risk-based inspection can also be used to set intervals where the owner’s program supports it.
Who can perform API inspection?
The codes require an inspector certified by API for the code concerned. NDT examiners who support the inspection are certified in their methods, and the owner-user remains responsible for the inspection program.
Does the equipment have to be shut down?
Not for everything. External inspection and most thickness readings are done with the equipment in service. Internal inspection of vessels and tanks needs them out of service, cleaned and safe to enter, and is usually planned into a turnaround or outage.
Tell us the equipment, the code, the last inspection date and any earlier reports, and whether the work is in service or during a turnaround. Call 1-844-MIDGARD, email contact@midgardscientific.com, or use the contact page.