API 6A – 20th Edition

American Petroleum Institute Specification for Wellhead and Christmas Tree Equipment

ANSI/API Specification 6A, 20th Edition

“Required NDE Testing”

Bodies, Bonnets, End and Outlet Connections, Clamp Hub Connectors and Stems

PSL 1 – Required Non-Destructive Testing

  1. Material NDE – Hardness Testing
    • Sampling per ISO 2859-1:1999. Level II, 4.0 AQL for parts 2,000 – 5,000 psi and 100% for parts with working pressures between 10,000 –20,000 psi. Loose connectors do not require hardness testing. All testing shall be performed at a location determined by the manufacturer’s specification and following the last heat treatment cycle (including all stress-relieving heat treatment cycles) and all exterior machining at the test location.
  2. Material NDE – Visual Examination
    • Each part shall be visually inspected
  3. Weld NDE – General
    • The essential welding variables and equipment shall be monitored; welding activities shall be audited. Requirements and acceptance criteria for corrosion-resistant weld overlay can be different from those for other weld types and shall meet the manufacture’s written specifications. The manufacturer’s written specification for corrosion-resistant weld overlay shall include a technique for measuring the specified overlay thickness.

PSL 2 – Required Non-Destructive Testing

  1. Material NDE – Hardness Testing
    • All parts shall be tested.
    • All testing shall be performed at a location determined by the manufacturer’s specification and following the last heat treatment cycle (including all stress-relieving heat treatment cycles) and all exterior machining at the test location.
  2. Material NDE – Visual Examination
    • Required for Non-wetted and non-sealing surfaces.
  3. Material NDE – Surface Examination
    • All accessible wetted surfaces and all accessible sealing surfaces of each finished part shall be examined by liquid-penetrant or magnetic-particle methods after final heat treatment and final machining operations.
  4. Weld NDE – General
    • The essential welding variables and equipment shall be monitored; welding activities shall be audited. Requirements and acceptance criteria for corrosion-resistant weld overlay can be different from those for other weld types and shall meet the manufacture’s written specifications. The manufacturer’s written specification for corrosion-resistant weld overlay shall include a technique for measuring the specified overlay thickness.
  5. Weld NDE – Visual Examination
    • 100% of all welds shall be visually examined after all post-weld heat treatment and machining operations.
  6. Weld NDE – Surface Examination
    • 100% of all pressure-containing fabrication welds and weld overlay shall be examined after all welding, post welding, post-weld heat treatment and machining operations.
  7. Weld NDE – Volumetric Examination
    • 100% of all pressure-containing welds shall be examined by either radiography or ultrasonic methods after all welding, post-weld heat treatment and machining operations but prior to machining operations that limit effective interpretation of the results of the examination.

PSL 3 – Required Non-Destructive Testing

  1. Material NDE– Volumetric Examination
    • As far as practical, the entire volume of each part shall be volumetrically inspected (radiograph or ultrasonic) after heat treatment for mechanical properties and prior to machining operations that limit effective interpretation of the results of the examination.
  2. Material NDE– Hardness Testing
    • All parts shall be tested, including each finished part (body, bonnet, and end connections) with additional test on each end connection face at locations specified in the manufacturer’s design documents. All testing shall be performed at a location determined by the manufacturer’s specification and following the last heat treatment cycle (including all stress-relieving heat treatment cycles) and all exterior machining at the test location.
  3. Material NDE– Surface Examination
    • All surfaces prepared for “weld metal overlay” and all accessible surfaces of each finished part shall be inspected. Additionally, magnetic particle examinations shall use the wet fluorescent method.
  4. Weld NDE – General
    • The essential welding variables and equipment shall be monitored; welding activities shall be audited. Requirements and acceptance criteria for corrosion-resistant weld overlay can be different from those for other weld types and shall meet the manufacture’s written specifications. The manufacturer’s written specification for corrosion-resistant weld overlay shall include a technique for measuring the specified overlay thickness.
  5. Weld NDE – Visual Examination
    • 100% of all welds shall be visually examined after all post-weld heat treatment and machining operations.
  6. Weld NDE – Surface Examination
    • 100% of all pressure-containing fabrication welds and weld overlay shall be examined after all welding, post welding, post-weld heat treatment and machining operations. Additionally, magnet-particle examination shall be performed by the wet fluorescent method.
  7. Weld NDE – Volumetric Examination
    • 100% of all pressure-containing welds shall be examined by either radiography or ultrasonic methods after all welding, post-weld heat treatment and machining operations but prior to machining operations that limit effective interpretation of the results of the examination.
  8. Weld NDE – Hardness Examination
    • 100% of all accessible pressure-containing, non-pressure-containing and repair welds.

PSL 4 – Required Non-Destructive Testing

  1. Material NDE – Volumetric Examination
    • As far as practical, the entire volume of each part shall be volumetrically inspected (radiograph or ultrasonic) after heat treatment for mechanical properties and prior to machining operations that limit effective interpretation of the results of the examination.
  2. Material NDE – Hardness Testing
    • All parts shall be tested, including each finished part (body, bonnet, and end connections) with additional test on each end connection face at locations specified in the manufacturer’s design documents. All testing shall be performed at a location determined by the manufacturer’s specification and following the last heat treatment cycle (including all stress-relieving heat treatment cycles) and all exterior machining at the test location.
  3. Material NDE – Surface Examination
    • All surfaces prepared for “weld metal overlay” and all accessible surfaces of each finished part shall be inspected. Additionally, magnetic particle examinations shall use the wet fluorescent method.
  4. Weld NDE – Surface Examination
    • No welding except overlay is permitted. 100% of all weld overlay shall be examined after all welding, post-weld heat treatment and machining operations. Additionally, any magnet-particle examination shall be performed by the wet fluorescent method.

 


Disclaimer:

  • All provided information is only intended to be informative about the basic required NDE testing and does not include any Tensile, Impact, Dimensional, Traceability or Chemical Analysis testing that may be required per API 6A, 20th
  • All provided information is only intended to simplify the NDE requirements of API 6A, 20th The code should be used when requesting or preforming inspections.
  • Some companies may require additional testing other than what is listed above.
  • Referenced Specification: API 6A, 20th Edition