Computed Radiography (CR)

Computed Radiography (CR)

Computed radiography (CR) is used to assess internal or external corrosion/erosion losses in process piping, pressure vessels and valves. Based on it one can estimate remaining thickness and wall losses. The computerized images allow easy data sharing and result in significant improvements in radiographic inspection productivity as well as faster identification of defects. Computed Radiography system can be used for following below mentioned applications.

  1. Piping for internal corrosion or for corrosion under insulation (CUI).
  2. Valves and their internals for internal or external corrosion/erosion
  3. Piping and valves for build-up of products and for blocks.
  4. Newly fabricated welds according to:
    • ASME Section V for pressure vessels
    • ASME B31.1 and B31.3 for piping
    • API 1104 for pipelines
  5. For losses in boiler tubes at temperatures of the order of 350 ⁰C.
  6. Asbestos insulated equipment and assess losses around the circumference (not only those perpendicular to the radiation source)
  7. In-service welds

ADVANTAGES

  1. The images can be readily shared, e-mailed and stored electronically by anyone needing reliability information for the equipment.
  2. The imaging plates practically eliminate re-shots by providing a greater range over which exposures can be useful.
  3. Significant exposure reductions
    • Reduction of exposure times from 40-60% when using IR 192
    • Similar or better results are obtained when utilizing Se 75, Co60 and X-rays
    • Highly reproducible
  4. Images on film or digitized
  5. Data is stored for future comparison or audit

LIMITATIONS

  1. Radiation safety considerations are the same for CR as standard radiography
  2. An equipment reading station is required to scan the imaging plates
  3. Physical space and on-site electrical power are required to set up the equipment
  4. Requires access to both sides of the part
ircenggComputed Radiography (CR)