What are the inspection techniques that should be used for the evaluation of coker drums?

ID  deformation measurement by TOFD or laser equipment  

Wall Thickness Inspection,  Magnetic Particle Test. 

• Corrosion Mapping
• Ultrasonic thickness measurement and flaw detection
• Magnetic-particle examination for cracks and other elongated discontinuities
• Magnetic Flux Leakage Screening

Visual , Wall thickness Inspection,DPT/MT

• 3D Laser Scanning and Remote Visual Inspection (RVI) tools
• Stress Concentration Factors (SCF)

phased array ultrasond testing and Tofd 

What is this Coker drum? and for what purpose it does use?

Inspection of Coke Drums may require the use of Automated Pulse Echo or Time of Flight Diffraction Techniques (TOFD).

Visual inspection and dye penetrant should be used.

Wall thickness Inspection,

Welding joint Inspection using NDT techniques

Coke drums can inspected during turnaround with 3D Laser scanning and remote visual inspection (RVI) tools, resulting in a detected dimensional and visual evaluation of the internal surface.