X-ray Radiography
Applications:
- Air craft structures
- Structural steel works
- Ship building
- Pressure vessels and boilers
- Penstocks, etc.
Advantages
- Provides permanent record on film
- Technique standardized
- Reference standards available
- Adjustable energy level gives high sensitivity
- Fluoroscopy techniques available
Limitations
- Trained technician needed
- Radiation hazards
- High cost of equipment
- Power source needed
Gamma-ray Radiography
Applications
- Pipe work
- Penstocks
- Pressure vessels and boilers
- Structural steel works
- Ship building
Advantages
- Provides permanent record on film
- Technique standardized
- Reference standards available
- Low initial cost
- Portable, independent of power supply
- Makes panoramic exposures
Limitations
- Trained technician needed
- Radiation hazards
- Fixed energy levels per source
- Source looses strength continuously
- Generally lower sensitivity and definition than x-ray radiography
Ultrasonic Testing
Applications
- All types of welded work in metallic and non metallic materials
Advantages
- Safe to use
- Fast method
- Results available immediately
- Sensitive
- Indicates presence of laminations and other plannar defects
- Indicates depth of flaw
Limitations
- Entirely dependent on operator skill
- Unsuitable for welding of complex shape or configuration
- Requires surface contact
- Surface must be clean and smooth
Magnetic Particle Testing
Applications
- Welds, particularly fillet welds, in all ferro magnetic materials
Types of Faults Indicated
- Cracks, Porosity, Inclusions and discontinuities at or close to the surface
Advantages
- Simple to use and interpret
- Portable and relatively inexpensive
Limitations
- Material must be ferro magnetic
- Demagnetization may be needed
- Power source required
Liquid Penetrant Testing
Applications
- All welds in ferrous and non ferrous materials and in non metallic materials
Advantages
- Simple to use and interpret
- Relatively inexpensive
- Portable and require no elaborate equipment
- Work on all materials
Limitations
- Only surface defect will be detected
- Surface must be clean and dry
- Rust or paint will mask defects