Power Plant NDT Services: Boilers, HRSGs, Turbines and Piping

What does power station NDT cover?

Power station NDT examines the components that crack or thin in service and are found at outages: boiler waterwall, superheater and reheater tubes and their welds, headers and drums, HRSG tubes and headers, high-energy piping, and turbine and generator parts. Atlantis NDT mobilises technicians for planned outages anywhere in the USA; radiography, where the code requires it, is scoped with the job.

Boiler tube weld inspection

Boiler tube butt welds are thin-walled and closely spaced. ASME Section I paragraph PW-11 sets the radiographic and ultrasonic examination of welded butt joints in boilers, and ASME B31.1 Table 136.4 sets the type and extent of mandatory examination for power piping welds; the US Coast Guard's rules for marine boilers and piping cite the same paragraph and table (46 CFR 52.05-20, 46 CFR 56.95-10).

Where the governing code or the owner's specification permits ultrasonic examination, encoded PAUT gives a recorded scan of each weld instead of a film, and the scan plan has to show coverage of the weld volume. Tube wall loss from fireside erosion or corrosion is a separate job: UT thickness on cleaned tube surfaces at recorded locations, so the next outage measures the same points.

Sources: ASME BPVC Section I, PW-11; ASME B31.1, Table 136.4; 46 CFR 52.05-20 and 56.95-10.

Headers, drums and high-energy piping

Welds and high-stress locations on headers, drums and high-energy piping are examined with UT, PAUT, TOFD and MT. Which locations are examined, the acceptance standard and any life assessment belong to the plant's engineering programme; the NDE report gives that programme located, sized indications and thickness readings it can trend from one outage to the next.

Who does what at an outage

Jurisdictional boiler and pressure vessel inspections are made by commissioned inspectors. The National Board of Boiler and Pressure Vessel Inspectors commissions in-service inspectors for the periodic inspections that jurisdictions require and Authorized Inspectors for the inspections the ASME Code requires. Atlantis NDT is not a commissioned or Authorized Inspector: it supplies the NDE those inspectors and your engineers rely on, and your inspector remains inspector of record.

Sources: National Board of Boiler and Pressure Vessel Inspectors, Commissioned Inspectors.

What you receive

• Examination records per weld, tube or location: method, procedure, extent and result
• Indications located and sized, and evaluated against the acceptance criteria you name
• Thickness readings tabulated against recorded locations you can find again at the next outage
• Technician certification and equipment calibration records
• A report reviewed by an ASNT NDT Level III before it is issued

Where we work: nationwide. Technicians are mobilised to your site anywhere in the USA; apart from the Houston office there is no local office, so mobilisation is planned and quoted for each job.

Power plant NDT: questions

Can PAUT replace radiography on boiler tube welds?

Where the construction code or the owner's specification permits ultrasonic examination, yes. The scan plan must show coverage of the weld volume, and acceptance comes from the governing code, not from the method.

Do you provide the jurisdictional boiler inspection?

No. Jurisdictional boiler and pressure vessel inspections are made by commissioned inspectors. Atlantis NDT supplies the NDE they rely on, and your inspector remains inspector of record.

What do you need from us to plan outage NDT?

The outage window, the components and weld or tube locations in scope, drawings or tube maps, materials, access and scaffolding plans, the acceptance code and the reporting format you need. Every job is quoted on request, and we reply within one business day.

Speak to an ASNT NDT Level III

Discuss your inspection requirements with Atlantis NDT. Include the asset, method, location and documents you need reviewed.